HomeMy WebLinkAboutAttachment 02d. - Geotechnical Update - Apr 2024UPDATE
GEOTECHNICAL REPORT
OTAY RANCH VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
PREPARED FOR
PROJECT NO. G1006-52-05
SEPTEMBER 30, 2022
REVISED MAY 5, 2023
Project No. G1006-52-05
September 30, 2022
Revised May 5, 2023
Homefed Otay Land II, LLC
1903 Wright Place, Suite 220
Carlsbad, California 92008
Attention: Mr. Jeff O’Connor
Subject: UPDATE GEOTECHNICAL REPORT
OTAY RANCH VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
Dear Mr. O’Connor:
In accordance with your authorization and our proposal LG-21228 dated May 4, 2021, we prepared this
update geotechnical report for the subject project. The accompanying report presents our findings,
conclusions and recommendations pertaining to the geotechnical aspects of the proposed development.
The study also includes an evaluation of the geologic units and geologic hazards. Based on the results
of this study, we opine the site is considered suitable for development provided the recommendations of
this report are followed.
Should you have any questions regarding this correspondence, or if we may be of further service, please
contact the undersigned at your convenience.
Very truly yours,
GEOCON INCORPORATED
Shawn Foy Weedon
GE 2714
Michael C. Ertwine
CEG 2659
SFW:MCE:am
(e-mail) Addressee
(e-mail) Hunsaker & Associates San Diego, Inc.
Attention: Ms. Alisa Vialpando
TABLE OF CONTENTS
1.PURPOSE AND SCOPE ...................................................................................................................... 1
2.SITE AND PROJECT DESCRIPTION ................................................................................................ 2
3.PREVIOUS SITE DEVELOPMENT ................................................................................................... 5
4.TEMPORARY GRADED SLOPES ..................................................................................................... 6
5.SUBDRAINS ........................................................................................................................................ 7
6.GEOLOGIC SETTING ......................................................................................................................... 8
7.SOIL AND GEOLOGIC CONDITIONS ............................................................................................. 9
7.1 Previously Placed Fill (Qpf) ....................................................................................................... 9
7.2 Undocumented Fill Soil (Qudf – Environmental Stockpile) .................................................... 10
7.3 Undocumented Fill Soil (Qudf) ................................................................................................ 10
7.4 Compacted Fill (Qcf) ................................................................................................................ 10
7.5 Topsoil (unmapped) .................................................................................................................. 11
7.6 Alluvium (Qal) ......................................................................................................................... 11
7.7 Terrace Deposits (Qt) ............................................................................................................... 11
7.8 Otay Formation (To, Tob and Tog) .......................................................................................... 11
8.GEOLOGIC STRUCTURE ................................................................................................................ 12
9.GROUNDWATER ............................................................................................................................. 12
10.GEOLOGIC HAZARDS .................................................................................................................... 13
10.1 Faulting and Seismicity ............................................................................................................ 13
10.2 Liquefaction .............................................................................................................................. 14
10.3 Landsliding ............................................................................................................................... 14
10.4 Seiches and Tsunamis ............................................................................................................... 15
10.5 Slope Stability ........................................................................................................................... 15
10.6 Erosion ...................................................................................................................................... 16
11.CONCLUSIONS AND RECOMMENDATIONS .............................................................................. 17
11.1 General ...................................................................................................................................... 17
11.2 Existing Grade Soil Conditions ................................................................................................ 18
11.3 Seismic Design Criteria – 2022 California Building Code ....................................................... 19
11.4 Slope Stability Analyses ........................................................................................................... 22
11.5 Grading ..................................................................................................................................... 23
11.6 Earthwork Grading Factors ....................................................................................................... 30
11.7 Subdrains .................................................................................................................................. 30
11.8 Preliminary Foundation and Concrete Slabs-On-Grade Recommendations............................. 33
11.9 Exterior Concrete Flatwork ...................................................................................................... 39
11.10 Conventional Retaining Walls .................................................................................................. 40
11.11 Lateral Loading ......................................................................................................................... 43
11.12 Preliminary Pavement Recommendations ................................................................................ 44
11.13 Slope Maintenance.................................................................................................................... 47
11.14 Site Drainage and Moisture Protection ..................................................................................... 48
11.15 Grading and Foundation Plan Review ...................................................................................... 49
11.16 Testing and Observation Services During Construction ........................................................... 49
TABLE OF CONTENTS (Concluded)
LIMITATIONS AND UNIFORMITY OF CONDITIONS
MAPS AND ILLUSTRATIONS
Figures 1 through 6, Geologic Map
Figures 7 and 8, Geologic Cross-Sections
APPENDIX A
PREVIOUS BORINGS AND TRENCH LOGS
APPENDIX B
LABORATORY TESTING
Table B-I, Summary of Laboratory Maximum Dry Density and Optimum Moisture Content Test Results
Table B-II, Summary of Laboratory Direct Shear Test Results
Table B-III, Summary of Laboratory Expansion Index Test Results
Table B-IV, Summary of Laboratory Water-Soluble Sulfate Test Results
Table B-V, Summary of Laboratory Atterberg Limits Test Results
Table B-VI, Summary of Laboratory Resistance Value (R-Value) Results
Figures B-1, Gradation Curve
APPENDIX C
SLOPE STABILITY ANALYSIS
APPENDIX D
RECOMMENDED GRADING SPECIFICATIONS
LIST OF REFERENCES
Geocon Project No. G1006-52-05 - 1 - September 30, 2022
Revised May 5, 2023
UPDATE GEOTECHNICAL REPORT
1. PURPOSE AND SCOPE
This report presents the results of an update geotechnical study for the proposed Otay Ranch Village 8
East development located in eastern portion of Chula Vista, California (see Vicinity Map).
Vicinity Map
The purpose of this update report is to provide excavation and remedial grading considerations,
foundation and concrete slab-on-grade recommendations, retaining wall and lateral load
recommendations, 2019 CBC seismic design criteria, preliminary pavement and flatwork
recommendations, and discussions regarding the local geologic hazards including faulting, liquefaction,
and seismic shaking. The scope of the study also included a review of:
1.Geotechnical Investigation, Otay Ranch Village 8 East, Chula Vista, California, prepared by
Geocon Incorporated, dated March 14, 2014 (Project No. G1006-11-02).
2.Final Report of Testing and Observation Services Performed During Site Grading, Otay Ranch
Village 8 East, Borrow and Disposal Sites, Chula Vista, California, prepared by Geocon
Incorporated, dated September 9, 2022 (Project No. G1006-52-04).
3.Tentative Map CVT-13-03, Otay Ranch Village 8 East, City of Chula Vista, prepared by
Hunsaker & Associates, San Diego, Inc., August 17, 2022 (W.O. No. 2395-0039).
Geocon Project No. G1006-52-05 - 2 - September 30, 2022
Revised May 5, 2023
Our referenced field investigation dated March 14, 2014 for Otay Ranch Village 8 East included
mapping the geology, drilling 19 large-diameter borings, and excavating 57 backhoe trenches. Appendix
A presents the logs of the previous borings and trenches. The approximate locations of the exploratory
excavations are presented on the Geologic Map (Figures 1 through 6). We performed laboratory tests
on soil samples obtained from the exploratory excavations to evaluate pertinent physical and chemical
properties for engineering analysis. The results of the laboratory testing are presented in Appendix B.
We performed engineering analyses to evaluate the stability of the proposed slopes. The results of our
slope stability analyses are discussed herein and analyses are presented in Appendix C.
Hunsaker & Associates San Diego, Inc. provided the topographic information and the tentative map
used during our field investigation and preparation of the Geologic Map. References to elevations
presented in this report are based on the referenced topographic information. Geocon does not practice
in the field of land surveying and is not responsible for the accuracy of such topographic information.
2. SITE AND PROJECT DESCRIPTION
Otay Ranch Village 8 East is located south of future Main Street (currently Rock Mountain Road) and
Olympian High School, west of State Route 125, north of the Otay River drainage and Wiley Road
access easement, and east of undeveloped land in the southeastern portion of Chula Vista, California.
The property is approximately 575 gross acres with about 265 gross acres planned for open space
resulting in the development of about 310 acres. The site consists of a series of south trending ridges
and canyons draining to the south into Otay River. Site elevations range from approximately 180 feet
above mean sea level (MSL) at the southwest corner of the Community Park site adjacent to the Otay
River drainage to approximately 610 feet MSL at the northeast corner of the site. Cut and fill slopes
exist on the northern portion of the site created during the previous grading of Main Street. A Chula
Vista sewer line easement and SDG&E overhead transmission lines are located on the southern portion
of the project within the un-improved Wiley Road. Wiley Road provides access to the Vulcan material
plant to the west and further east within the Otay River Valley. The City of San Diego’s, Otay 2nd 40-
inch and Otay 3rd 54-inch-inch waterlines (constructed in the late 1920s by cut and cover techniques)
cross the site from east to west in the middle portion of the project. We understand the invert elevations
of the pipeline are 10 to 15 below the existing grades based on observation of portion of mass grading
on Village 8 West. We understand the existing waterlines will be removed or abandoned from the eastern
and western points of connection, respectively. Portions of the existing 54-inch pipeline are partially
exposed above ground as it crosses several tributary drainages. Previous grading of Main Street and the
high school included the construction of canyon subdrains and a buttress fill. Site vegetation consists of
sparse native coastal sage scrub and grassland habitats disturbed by farming. Some riparian vegetation
occurs on the north side of the Otay River drainage area. The Project Location Map shows the areas
surrounding the Village 8 West development area.
Geocon Project No. G1006-52-05 - 3 - September 30, 2022
Revised May 5, 2023
Project Location Map
We understand the development will generally occur from the north to south property lines leaving local
areas designated as open space and preserve for environmental purposes (MSCP). The site will
accommodate multi-family residential (108.8), village core (47.7 acres), park sites (73.2 acres), school
site (11.3 acres), community purpose facilities (2.0 acres), parks (73.2 acres, respectively), future
development lots (9.3 acres), circulation roadways (31.8 acres), active recreation (22.6 acres), and open
space (253.6. acres of preserve land, and basins (31.6 acres). A large community park is proposed on
the southern portion of the property adjacent to the Otay River drainage channel. In addition, a water
quality basin will be constructed on the southeast and southwest portion of the site to the south of the
developed area and along the north side of the Otay River drainage. Grading of the site will consist of
maximum cuts and fills of approximately 75 feet with cut and fill slopes having a maximum height of
45 and 50 feet, respectively, and a maximum slope inclination of 2:1 (horizontal to vertical). Several
reinforced earth retaining walls are proposed on the site with maximum heights on the order of 25 feet.
The proposed grading will require approximately 4.86 million cubic yards of excavation and fill. The
Site Utilization plan is presented herein. This report does not include the design for the proposed bridges
extending over Highway SR-125 on La Media Parkway and Rock Mountain Road.
Geocon Project No. G1006-52-05 - 4 - September 30, 2022
Revised May 5, 2023
Site Utilization Map
A portion of Village 8 East has been utilized as a disposal site for rock-fill placement operations which
are ongoing. Prior to site grading in the disposal area, in accordance with the soil remediation plan,
topsoil material was stripped and stockpiled. The stockpiled material will be placed during mass-grading
operations in accordance with project specifications. Within the disposal site, remedial grading consisted
of removing the existing surficial materials in the proposed work area, installing subdrains (where
Geocon Project No. G1006-52-05 - 5 - September 30, 2022
Revised May 5, 2023
necessary) and placing soil-rock-fill from the Otay Ranch Village 8 West project. The rock is being
placed on the side of an existing slope to an elevation of about 425 to 440 feet MSL. The rock will be
placed at least 2 feet below the planned deepest utilities and at least 10 feet from the proposed finish
grade elevations. Soil: rock-fill is placement is completed and referenced in our report dated August 9,
2022.
The locations and descriptions provided herein are based on a site reconnaissance, review of the tentative
map, and project information provided by the client and Hunsaker & Associates, San Diego.
3. PREVIOUS SITE DEVELOPMENT
In general, a portion of Otay Ranch Village 8 East has been partially grading during mass grading
operations for Village 8 West. The disposal and borrow areas within Village 8 West consisted of
remedial grading of surficial soil and placing compacted fill resulting in a total maximum thickness
ranging up to approximately 40 feet. The surficial soil (topsoil) and upper weathered formational
materials were excavated to expose competent Otay Formation. The topsoil and portions of the
weathered Otay Formation were stockpiled for environmental purposes highlighted blue and labeled
environmental stockpile. Prior to fill placement, toe drains were installed and canyon subdrains were
placed within the former canyon drainages. The grading contractor generated additional fill material
from within the Otay Formation and placed within the lower temporary slope zone margins subsequent
to the installation of the toe drains. Excavation depths ranged from 5 feet within the former mesa areas
and up to 10 feet within the flanks of the central canyon drainage. The Geologic Maps, Figures 1 through
8, depict elevations of the base of the fill and environmental stockpiled material.
Imported materials from Otay Ranch Village 8 West generally varied between angular gravels and
boulders (produced by blasting of hard metavolcanic rock) to clayey, fine sand; sandy to silty clay; and
sandy to clayey gravels. Structural fill consists of materials that can be classified into three zones:
1. Zone A – Material placed within 3 feet of pad grade, 6 feet of parkway grade, and within
roadways to at least 1 foot below the deepest utility consisted of “soil” fill with a maximum
particle dimension of 6 inches.
2. Zone B – Material placed within 10 feet of pad grade and below Zone A consisted of “soil-rock”
fill with a maximum particle dimension of 12 inches. In addition, material placed on the outer
6 feet of fill slopes and 2 feet below Zone A for fills in roadways and parkways consisted of
“soil-rock” fill with a maximum particle dimension of 12 inches.
3. Zone C – Material placed below Zone B consisted of “soil-rock” fill and “rock” fill with a
maximum particle dimension of 4 feet. It should also be noted that larger rocks with a maximum
dimension of approximately 8 feet were buried individually during “soil-rock” fill grading
operations.
Geocon Project No. G1006-52-05 - 6 - September 30, 2022
Revised May 5, 2023
Based on our observations, only Zones B and C were placed in the disposal areas. We expect Zone A
will be placed during future mass grading operations during site development. Placement procedures for
“soil-rock” and “rock” fills consisted of spreading and compacting the material with a D9 or larger
Caterpillar bulldozer with a maximum lift size of 3 feet. Materials placed as “soil/rock” and “rock” fills
were watered heavily during spreading to place finer-grained material between the rocks. During the
placement of each lift, compaction effort was applied to the fill by wheel-rolling with loaded rock trucks
such that the entire lift was compacted.
Soil fills were placed in lifts no thicker than would allow for adequate bonding and compaction. The
soil was moisture conditioned as necessary and mixed during placement, then compacted utilizing
conventional heavy-duty compaction equipment.
During the disposal sites grading operations, we observed compaction procedures and performed in-
place density tests to evaluate the dry density and moisture content of the fill materials. We performed
in-place density tests in general conformance with ASTM Test Method D 6938 (nuclear). In general,
the in-place density test results indicate the compacted fill possesses a dry density of at least 90 percent
of the laboratory maximum dry density near to slightly above optimum moisture content at the locations
tested. The results of these tests are reported in the referenced Final Report of Grading dated
September 9, 2022. A summary of the observations, compaction test results, and professional opinions
pertaining to the grading is presented in the referenced interim reports of testing and observation services
performed during site grading.
4. TEMPORARY GRADED SLOPES
During the disposal site grading operations, the contractor constructed temporary fill slopes with a
maximum height of approximately 35 feet at inclinations of 2:1 (horizontal to vertical) or flatter. The
existing site conditions and approximate oversize rock fragments are presented on the Existing Site Plan.
Geocon Project No. G1006-52-05 - 7 - September 30, 2022
Revised May 5, 2023
Existing Site Plan
After remedial grading of the surficial soil and installation of toe drains, the western and eastern facing
embankment fill slopes were constructed along the margins of a shallow alluvial drainage. At the
direction of Terra Development Inc. and HomeFed, the contractor extended the soil-rock fill to the
temporary slope face instead of placing finer-grained compacted fill materials for placement on the outer
slope face as outlined in our letters dated October 9, 2020, and July 15, 2021. Although the contractor
properly placed the soil-rock fill, the slope surface areas of the soil-rock fill possess voids between the
rock fragments that will require additional remedial grading during future grading operations. Some
oversize rock will require special handling and benching techniques prior to additional fill placement.
5. SUBDRAINS
The grading contractor installed toe drains and a canyon subdrain at the general locations shown on the
As-Graded Geologic Map, Figures 1 and 2. In addition, the subdrains were “as-built” for location and
elevation by the project civil engineers, Hale Engineering, and Hunsaker & Associates, San Diego,
Incorporated. The canyon subdrains and toe drains consists of 6- to 8-inch-diameter, Schedule 40,
perforated PVC pipe placed in ¾-inch crushed aggregate gravel surrounded by Mirafi 140N (or
equivalent) filter fabric. The perforated pipe is connected to a solid pipe at the end of the drain near the
Geocon Project No. G1006-52-05 - 8 - September 30, 2022
Revised May 5, 2023
outlet. The canyon subdrains and toe drains have been outlet into open space as-depicted as the As-
Graded Geologic Map. These subdrains should be extended during the proposed mass grading
operations for the future development.
6. GEOLOGIC SETTING
The site is located in the coastal plain of the Peninsular Ranges province of southern California. The
Peninsular Ranges is a geologic and geomorphic province that extends from the Imperial Valley to the
Pacific Ocean and from the Transverse Ranges to the north and into Baja California to the south. The
coastal plain of San Diego County is underlain by a thick sequence of relatively undisturbed and non-
conformable sedimentary rocks that range in age from Upper Cretaceous through the Pleistocene with
intermittent deposition. Geomorphically, the coastal plain is characterized by a stair-stepped series of
marine terraces, which are younger to the west and have been dissected by west flowing rivers that drain
the Peninsular Ranges to the east. The coastal plain is a relatively stable block that is dissected by
relatively few faults consisting of the potentially active La Nacion Fault Zone and the active Rose
Canyon Fault Zone. The Peninsular Ranges are also dissected by the Elsinore Fault Zone that is
associated with and sub-parallel to the San Andreas Fault Zone, which is the plate boundary between
the Pacific and North American Plates.
The site is located on the central portion of the coastal plain. A prominent outcrop composed of
Metavolcanic Rock (Mzu) is located west of the site. Marine sedimentary units unconformably overlie
the Metavolcanic Rock and consist of a Pleistocene age Terrace Deposits (Qt) and the Tertiary age Otay
Formation (To). The Terrace Deposits are shallow marine and non-marine sandstone units with layers
containing cobble up to 18 inches in diameter. This unit is located on the southern portion of the site on
the northern flanks of the Otay River Valley. Otay Fanglomerate is mapped along the southern flanks
of the site; however, we do not expect to encounter it at the site. We expect this unit could be consistent
with the gritstone member discussed herein. The Otay Formation typically consists of three
lithostratigraphic members composed of a basal conglomerate member, a middle gritstone member and
an upper sandstone/siltstone/claystone member with a maximum reported regional thickness of roughly
400 feet. The upper two members of the Otay Formation are present on the site. In addition, bentonitic
claystone layers are common within the upper member typically deposited as highly consolidated
volcanic ash deposits. The site has been dissected by a series of northwest trending canyons that have
exposed the Otay Formation. Pleistocene-age Terrace Deposits are present on the northern flank of the
Otay River. A Regional Geologic Map is presented herein.
Geocon Project No. G1006-52-05 - 9 - September 30, 2022
Revised May 5, 2023
Regional Geologic Map
7. SOIL AND GEOLOGIC CONDITIONS
During our field investigation, disposal and borrow site grading operations, we encountered four
surficial deposits (consisting of previously placed fill, undocumented fill, topsoil, and alluvium) and two
formational units (consisting of Pleistocene age Terrace Deposits and Tertiary-age Otay Formation). We
subdivided the Otay Formation into the upper sandstone/siltstone/claystone member (To) and an
underlying middle gritstone member (Tog). We did not encounter the lower basal conglomerate member
of the Otay Formation on site. The lateral extent of the materials encountered is shown on the Geologic
Map, Figures 1 through 4. Figure 5 presents Geologic Cross-Sections providing an interpretation of the
subsurface geologic conditions. We prepared the geologic cross-sections using interpolation between
exploratory excavations and observations; therefore, actual geotechnical conditions may vary from those
illustrated and should be considered approximate. The descriptions of the soil and geologic conditions
are shown on the boring logs located in Appendix A, the laboratory testing in Appendix B, and described
herein in order of increasing age.
7.1 Previously Placed Fill (Qpf)
Previous grading has occurred along the northern portion of the site during the construction of Main
Street and the adjacent high school consisting of the placement of previously placed fill. The previous
grading was completed in 2005 with the testing and observation services provided by Geotechnics
Incorporated (see List of References). The grading consisted of the removal of surficial soil, placement
Geocon Project No. G1006-52-05 - 10 - September 30, 2022
Revised May 5, 2023
of two canyon subdrain and two soil-rock fill subdrains, and the placement and compaction of fill soil
to achieve finish grades. The two canyon subdrains should be extended up-gradient during mass grading
operations to 10 feet below proposed grades. A buttress fill constructed during grading in 2007 possesses
a subsurface drain constructed on the ascending slope on the south side of Main Street on the western
portion of the roadway (see Geologic Map). During mass-grading for Otay Ranch Village 8 East,
performed by AGS, Inc. the 8-inch subdrain has been outlet to an approved structure along Main Street
East during the site development within Village 8 East. In general, the fill consists of medium dense to
dense, moist, silt and sand. In its present condition, the fill soil is suitable for support of additional fill
or utilities; however, the upper portion of the fill soil will require remedial grading.
7.2 Undocumented Fill Soil (Qudf – Environmental Stockpile)
Undocumented fill soil is present as stockpiles on the site adjacent to the disposal and borrow areas. The
contractor placed stockpiles during the soil remediation program topsoil material which consists of
stripped and stockpiled topsoil and surficial materials. The stockpiled material will be placed during
mass-grading operations in accordance with project specifications. The undocumented fill possesses a
thickness of at least 10 to 35 feet thick and can be characterized as soft to loose, dry to damp, sandy clay
to clayey sand. The undocumented fill is compressible and removal will be necessary within the limits
of grading in areas to support proposed fill or structures, or in areas of additional removals and placement
of additional compacted.
7.3 Undocumented Fill Soil (Qudf)
Undocumented fill soil is also present on the central portion of the site adjacent to and within the existing
City of San Diego Otay 2nd and 3rd pipelines. The fill was likely placed during the excavation of the
aqueduct and to traverse the property. The undocumented fill likely has a thickness of at least 10 to 15
feet thick and can be characterized as soft to loose, dry to damp, sandy clay to clayey sand. The
undocumented fill is compressible and removal will be necessary within the limits of grading in areas
to support proposed fill or structures.
7.4 Compacted Fill (Qcf)
Compacted fill associated with the grading operations exists on the partially graded disposal sites. In
general, the fill consists of soil-rock fills generated from the neighboring Otay Ranch Village 8 West.
The contractor placed fill materials generated from the excavations within metavolcanic rock areas in
Otay Ranch Village 8 East and placed as compacted fill. The outside edge of the temporary fill slopes
consists of a rockfill which will require additional remedial during mass grading operations. The
compacted fill is considered suitable for support and development of proposed improvements; however,
the upper portions, and temporary rock fill areas will require processing and recompaction prior to
placing fill or improvements.
Geocon Project No. G1006-52-05 - 11 - September 30, 2022
Revised May 5, 2023
7.5 Topsoil (unmapped)
Holocene-age topsoil is present as a relatively thin veneer overlying formational materials across the
site. The topsoil has a thickness of approximately 2 to 4 feet and can be characterized as soft to stiff and
loose to medium dense, dry to damp, dark brown, sandy clay to clayey sand with gravel and cobble. The
topsoil is typically expansive and compressible. Removal of the topsoil will be necessary within the
limits of grading in areas to support proposed fill or structures. Due to the relatively thin thickness and
discontinuity of these deposits, topsoil is not shown on the Geologic Map.
7.6 Alluvium (Qal)
Holocene-age alluvium is sheet-flow or stream deposited material found within the canyon drainages
and the southern river area. The alluvium generally varies in thickness dependent on the size of the
canyon and extent of the drainage area. The alluvium within the canyon drainages is loose to medium
dense, can become saturated and difficult to excavate during the rainy season. We estimate the thickness
of the alluvium to range up to approximately 7 feet within the tributary canyons and 11 feet within the
Otay River Drainage on the south side of the site. Due to the relatively unconsolidated nature of these
deposits, remedial grading will be necessary in areas to receive proposed fill or structures.
7.7 Terrace Deposits (Qt)
Pleistocene-age Terrace Deposits are deposited as shallow marine and non-marine near shore soil
located on the southern portion of the site and the northern flank of the Otay River canyon drainage. We
expect this unit may be in excess of 50 feet thick. The Terrace Deposits are generally dense to very
dense, reddish brown, silty to clayey sandstone with portions of the unit containing intermittent layers
of cobbles and boulders up to about 2 feet in diameter. The Terrace Deposits are suitable for the support
of proposed fill and structural loads; however, select grading operations will be required to properly
place the cobble and boulders where encountered.
7.8 Otay Formation (To, Tob and Tog)
Tertiary-age Otay Formation is exposed across the site or located below the surficial soil and Terrace
Deposits. The upper member of this unit (To) consists of interbeds of dense to very dense, slightly
cemented, silty to clayey sandstone and hard, siltstone and claystone layers. In addition, several layers
of bentonitic claystone (Tob) with a maximum thickness of approximately 1 foot thick are present within
this unit on the northern and middle portions of the site that can create slope instability. Some of the
layers are locally discontinuous and range in elevations as high as 573 feet MSL to as low as 416 feet
MSL. The approximate locations of the more prominent layers of bentonite are presented on the
Geologic Map, Figures 1 through 4. Some minor discontinuous layers of bentonitic claystone are also
present with a thickness of 1 to 3 inches. The bentonite did not appear to be sheared or remolded as
observed in our previous excavation.
Geocon Project No. G1006-52-05 - 12 - September 30, 2022
Revised May 5, 2023
The middle gritstone Otay Formation member (Tog), generally located below an elevation of 370 feet
MSL, consists of very dense, slightly to moderately cemented, silty to clayey sandstone with interbeds
of gravel and cobble generally with a maximum dimension of about 1 foot. We do not expect to
encounter the lower basal conglomerate member of the Otay Formation. Excavations within both the
upper and middle members will generally be possible with heavy-duty grading equipment with heavy
effort; however, moderately cemented zones will create very difficult ripping and generate oversize
cemented cobbles and boulders. The Otay Formation is suitable for the support of proposed fill and
structural loads. The gritstone member of this unit is generally stable when excavated to construct cut
slopes. However, the siltstone, claystone, and bentonitic claystone layers within the member will require
slope stabilization when exposed in cut slopes, near fill slopes, and behind MSE retaining walls.
The Tertiary-age (upper Oligocene) Otay Formation underlies the site on canyon slopes or underlying
the younger geologic formations and surficial soil at depth. The Otay Formation consists of dense, silty,
fine- to coarse-grained sandstone, clayey and sandy siltstone, and silty claystone with continuous and
discontinuous interbeds of highly expansive bentonitic claystone. The coarse-grained portions of the
Otay Formation typically possess a “very low” to “low” expansion potential (expansion index of 50 or
less) and adequate shear strength. The fine-grained siltstone and claystone portions of the formation can
exhibit a “medium” to “very high” expansion potential (expansion index greater than 50). With the
exception of the bentonitic claystone, the Otay Formation is suitable for the support of compacted fill
and structural loads.
8. GEOLOGIC STRUCTURE
Bedding attitudes observed within formational materials encountered during the investigation are nearly
horizontal to slightly dipping toward the southwest. The regional dip of sedimentary units in the eastern
Chula Vista area is generally 1 to 5 degrees toward the southwest. The granular portions of the
formational units are typically massive with bedding not discernible. Shear zones create a possibility for
slope instability and, where encountered during grading, should be evaluated for the necessity of
remedial grading. High-angle contacts between formational units are not uncommon; however, it is our
opinion that adverse geologic structure does not present a significant geologic hazard to the proposed
development of the site if the recommendations of this report are incorporated into design and
construction.
9. GROUNDWATER
We did not encounter a static groundwater table in the previous exploratory excavations and during the
grading operations. We do not expect groundwater to adversely impact the development of the property.
During storm drain excavations we observed minor seepage within formational materials. It is not
uncommon for groundwater seepage conditions to develop where none previously existed due to the
permeability characteristics of the geologic units encountered on site. During the rainy season, perched
Geocon Project No. G1006-52-05 - 13 - September 30, 2022
Revised May 5, 2023
water conditions are likely to develop within the drainage areas that may require special consideration
during grading operations. Groundwater elevations are dependent on seasonal precipitation, irrigation,
and land use, among other factors, and vary as a result.
10. GEOLOGIC HAZARDS
10.1 Faulting and Seismicity
A review of the referenced geologic materials and our knowledge of the general area indicate that the
site is not underlain by active, potentially active, or inactive faults. An active fault is defined by the
California Geological Survey (CGS) as a fault showing evidence for activity within the last
11,000 years. The site is not located within a State of California Earthquake Fault Zone.
The USGS has developed a program to evaluate the approximate location of faulting in the area of
properties. The following figure shows the location of the existing faulting in the San Diego County and
Southern California region. The fault traces are shown as solid, dashed and dotted that represent well-
constrained, moderately constrained and inferred, respectively. The fault line colors represent faults with
ages less than 150 years (red), 15,000 years (orange), 130,000 years (green), 750,000 years (blue) and
1.6 million years (black).
Faults in Southern California
The San Diego County and Southern California region is seismically active. The following figure
presents the occurrence of earthquakes with a magnitude greater than 2.5 from the period of 1900
through 2015 according to the Bay Area Earthquake Alliance website.
Geocon Project No. G1006-52-05 - 14 - September 30, 2022
Revised May 5, 2023
Earthquakes in Southern California
Considerations important in seismic design include the frequency and duration of motion and the soil
conditions underlying the site. Seismic design of structures should be evaluated in accordance with the
California Building Code (CBC) guidelines currently adopted by the City of Chula Vista.
10.2 Liquefaction
Liquefaction typically occurs when a site is located in a zone with seismic activity, onsite soils are
cohesionless or low plasticity silt/clay, static groundwater is encountered within 50 feet of the surface,
and soil relative densities are less than about 70 percent. If the four previous criteria are met, a seismic
event could result in a rapid pore-water pressure increase from the earthquake-generated ground
accelerations. Seismically induced settlement may occur whether the potential for liquefaction exists or
not. The potential for liquefaction and seismically induced settlement occurring within the site soil is
considered to be very low due to the dense nature of proposed fill and the very dense nature of the
formational materials.
10.3 Landsliding
We did not observe evidence of landslide deposits within the proposed development area or adjacent to
the property during the geotechnical investigation or during previous grading operations. Therefore,
landslides are not considered a potential geologic hazard at the site.
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Revised May 5, 2023
10.4 Seiches and Tsunamis
A tsunami is a series of long period waves generated in the ocean by a sudden displacement of large
volumes of water. Causes of tsunamis include underwater earthquakes, volcanic eruptions, or offshore
slope failures. The site is approximately 9 miles from the Pacific Coast and finish grades will range
between approximately 180 feet and 540 feet above MSL after grading. Therefore, we consider the risk
associated with tsunamis to be negligible.
A seiche is a run-up of water within a lake or embayment triggered by fault- or landslide-induced ground
displacement. The site is not located near or adjacent to a large body of water. However, the Otay River
drainage channel along the south side of the site is located downstream of Lower Otay Lake located
approximately 2 miles to the east. The lowest elevation at the site after grading is proposed to be
approximately 25 feet above the drainage channel. Therefore, the potential of seiches affecting the site
or flooding due to a breach or overtopping of the dam structure is considered very low.
10.5 Slope Stability
We evaluated the maximum proposed cut and fill slope heights and MSE wall configurations, as
depicted on the Geologic Map, to evaluate both surficial and global stability based on the current
geologic information. The portions of the site planned for grading are generally underlain by
Quaternary-age surficial soil, Quaternary-age Terrace Deposits, and Tertiary-age Otay Formation. The
unit most likely to be subject to slope instability is the bentonitic claystone layers within the upper
member of the Otay Formation encountered on the northern and middle portions of the site. Appendix
C presents the slope stability analyses using the two-dimensional computer program GeoStudio2018
created by Geo-Slope International Ltd. The proposed slopes and MSE retaining walls have calculated
factors of safety greater than 1.5 for global and shallow sloughing conditions provided our
recommendations for grading and drainage are incorporated into the design and construction of the
proposed slopes and MSE retaining walls. We expect extended grid lengths will be required for the
planned MSE walls to have an appropriate factor of safety as shown in Appendix C.
In general, we opine permanent, graded fill slopes constructed of granular soil and cut slopes excavated
within the middle member of the Otay Formation and Terrace Deposits at the site with gradients of 2:1
(horizontal to vertical) or flatter will possess Factors of Safety of 1.5 or greater. However, stability fills
will be required on the cut slopes where the siltstone/claystone members of the Otay Formation are
encountered and where loose or cohesionless material is encountered. In addition, a buttress fill will be
required during grading operations on the eastern portion of the site (See Geologic Cross-Sections E-E’,
F-F’ and H-H’) and next to Otay Valley Road (See Geologic Cross-Section D-D’) where bentonite will
be encountered in the slope zone during grading operations The buttresses will require a minimum
widths ranging from 15 to 30 feet, as calculated. We will evaluate the length and location of the buttress
when the 40-scale grading plans have been prepared. A structural setback would be required behind the
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Revised May 5, 2023
buttress shown on Geologic Cross-Section F-F’ to keep the required buttress within the limits of grading.
We should review the grading report for SR-125 to check is a buttress was installed adjacent to the
roadway.
Grading of cut and fill slopes should be designed in accordance with the requirements of the local
building codes of the City of Chula Vista and the 2019 California Building Code (CBC). Mitigation of
unstable cut slopes can be achieved by the use of drained stability or buttress fills.
Slopes should be landscaped with drought-tolerant vegetation having variable root depths and requiring
minimal landscape irrigation. In addition, slopes should be drained and properly maintained to reduce
erosion.
10.6 Erosion
The site is not located adjacent to the Pacific Ocean coast or a free-flowing drainage where active erosion
is occurring. Provided the engineering recommendations herein are followed and the project civil
engineer prepares the grading plans in accordance with generally-accepted regional standards, we do
not expect erosion to be a major impact to site development. In addition, we expect the proposed
development would not increase the potential for erosion if properly designed.
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Revised May 5, 2023
11. CONCLUSIONS AND RECOMMENDATIONS
11.1 General
11.1.1 From a geotechnical engineering standpoint, we opine the site is suitable for development
provided the recommendations presented herein are implemented in design and construction
of the project.
11.1.2 Based on observations and test results, we opine the grading to which this report pertains has
been performed in conformance with the recommendations of the previously referenced
project soils report prepared by Geocon Incorporated, dated March 14, 2014, our letters dated
October 9, 2020 and July 15, 2021, and the geotechnical requirements of the grading plans.
11.1.3 We did not observe soil or geologic conditions during grading that would preclude the
continued development of the property as planned. Based on laboratory test results and field
observations, the fill observed and tested as part of the grading for this project was generally
compacted to a dry density of at least 90 percent of the laboratory maximum dry density near
to slightly above optimum moisture content.
11.1.4 The site is underlain by compacted fill overlying the Otay Formation. We observed the
placement of compacted fill during the mass grading operations and performed in-place
density tests to evaluate the dry density and moisture content of the fill material.
11.1.5 We opine soil within fill areas with residual pesticides was stockpiled during disposal site
grading operations. Topsoil was not placed as compacted fill.
11.1.6 Potential geologic hazards at the site include seismic shaking, and low to highly plastic
claystone layers, expansive and compressible soil. Based on our investigation, observations
during previous grading operations, and available geologic information, active, potentially
active, or inactive faults are not present underlying or trending toward the site.
11.1.7 The existing surficial soil units including undocumented fill associated with previous grading
and the backfill operations of the existing Otay 2nd and 3rd pipeline, topsoil and alluvium are
potentially compressible and unsuitable in their present condition for the support of
compacted fill or settlement-sensitive improvements. Remedial grading of the surficial soil
will be required and recommendations for remedial grading are provided herein. The
compacted fill, previously placed fill, Terrace Deposits and Otay Formation are suitable for
the support of proposed fill and structural loads.
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Revised May 5, 2023
11.1.8 We did not encounter groundwater during our subsurface exploration and we do not expect it
to be a constraint to project development. However, seepage within near surface formational
materials and perched groundwater conditions within the canyon drainages may be
encountered during the grading operations, especially during the rainy seasons. The
installation of canyon subdrains and drained buttress and stability fills will be required to be
constructed during grading operations.
11.1.9 The rippability of the surficial units is expected to range from easy to moderate. We expect
the Terrace Deposits and Otay Formation to be rippable with heavy to very heavy effort to
proposed finish grades. Cobbles/boulders and cemented zones should be expected within
portions of Terrace Deposits. Cemented zones should be expected within portions of the
gritstone member of the Otay Formation and Terrace Deposits that will require extra ripping
effort using D-10 bulldozers to excavate. Oversize material will likely be generated during
ripping operations within the Otay Formation and special grading techniques will be required.
11.1.10 In general, cut slopes composed of the middle member of the Otay Formation (Tog) and
Terrace Deposits (Qt) should possess a Factors of Safety at least 1.5 at inclinations of 2:1
(horizontal to vertical), or flatter. However, construction of a buttress fill will be required
where bentonite is exposed at or near the slope face such as on the eastern portion of the site.
Geologic Cross-Section F-F′ requires a buttress width of at least 30 feet to provide a minimum
factor of safety of 1.5. Construction of stability fills for proposed cut slopes within the upper
sandstone/siltstone/claystone member of the Otay Formation (To) on the northern and middle
portions of the site.
11.1.11 Proper drainage should be maintained in order to preserve the engineering properties of the
fill in the sheet-graded pad and slope areas. Recommendations for site drainage are provided
herein.
11.1.12 The site is considered suitable for the use of conventional continuous and spread footings with
a concrete slab-on-grade system or a post-tensioned foundation system.
11.2 Existing Grade Soil Conditions
11.2.1 The soil encountered in the field investigation is considered to be “expansive” (expansion
index [EI] greater than 20) as defined by 2022 California Building Code (CBC) Section
1803.5.3. Additional expansion index testing should be performed subsequent to the grading
operations to evaluate the expansion potential of the upper 3 to 4 feet of soil within the areas
of proposed structures and improvements. Table 11.2 presents soil classifications based on
the expansion index.
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Revised May 5, 2023
TABLE 11.2
EXPANSION CLASSIFICATION BASED ON EXPANSION INDEX
Expansion Index (EI) Expansion Classification 2022 CBC
Expansion Classification
0 – 20 Very Low Non-Expansive
21 – 50 Low
Expansive 51 – 90 Medium
91 – 130 High
Greater Than 130 Very High
11.2.2 Based on laboratory tests performed during our field investigation, the EI of the surficial soil,
Terrace Deposits and the Otay Formation is variable. We expect the surficial soils will possess a
“medium” to “high” expansion potential (EI of 51 to 130). The bentonitic claystone and siltstone
layers within the upper sandstone/siltstone/claystone member of the Otay Formation may possess
a “very high” expansion potential (EI greater than 130). The sandstone layers within the upper and
middle members of the Otay Formation will likely possess a “very low” to “low” expansion
potential (EI of 50 or less). The siltstone and claystone layers within the upper member of the Otay
Formation will likely possess a “medium” to “high” expansion potential (EI of 51 to 130). Due to
the range of expansion potential typically exhibited by the Otay Formation, the expansion potential
should be evaluated for the building pads once final grade is achieved. The undercutting of cut
lots within the Otay Formations should also be performed.
11.2.3 Based on review of the referenced geotechnical reports, laboratory tests on samples of the site
materials to evaluate the percentage of water-soluble sulfate content indicate the on-site
materials at the locations tested possess “S0” sulfate exposure to concrete structures as defined
by 2022 CBC Section 1904 and ACI 318-14 Chapter 19. Table 9.2 presents a summary of
concrete requirements set forth by 2019 CBC Section 1904 and ACI 318. The presence of
water-soluble sulfates is not a visually discernible characteristic; therefore, other soil samples
from the site could yield different concentrations. Additionally, over time landscaping
activities (i.e., addition of fertilizers and other soil nutrients) may affect the concentration.
11.2.4 Geocon Incorporated does not practice in the field of corrosion engineering. Therefore, further
evaluation by a corrosion engineer may be performed if improvements that could be
susceptible to corrosion are planned.
11.3 Seismic Design Criteria – 2022 California Building Code
11.3.1 Table 11.3.1 summarizes site-specific design obtained from the 2022 California Building
Code (CBC; Based on the 2021 International Building Code [IBC] and ASCE 7-16), Chapter
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Revised May 5, 2023
16 Structural Design, Section 1613 Earthquake Loads. We used the computer program U.S.
Seismic Design Maps, provided by the Structural Engineers Association (SEA) to calculate
the seismic design parameters. The short spectral response uses a period of 0.2 second. The
structures should be designed using Site Class C where there is less than 20 feet of fill and
Site Class D where the fill thickness is 20 feet or greater. We evaluated the Site Class based
on the discussion in Section 1613.2.2 of the 2022 CBC and Table 20.3-1 of ASCE 7-16. The
values presented herein are for the risk-targeted maximum considered earthquake (MCER).
Sites designated as Site Class D, E and F may require additional analyses if requested by the
project structural engineer and client.
TABLE 11.3.1
2019 CBC SEISMIC DESIGN PARAMETERS
Parameter Value 2022 CBC Reference
Site Class C D Section 1613.2.2
Fill Thickness, T (feet) T<20 T>20 --
MCER Ground Motion Spectral Response
Acceleration – Class B (short), SS 0.745g 0.745g Figure 1613.2.1(1)
MCER Ground Motion Spectral Response
Acceleration – Class B (1 sec), S1 0.272g 0.272g Figure 1613.2.1(2)
Site Coefficient, FA 1.202 1.202 Table 1613.2.3(1)
Site Coefficient, FV 1.5 1.5* Table 1613.2.3(2)
Site Class Modified MCER Spectral Response
Acceleration (short), SMS 0.895g 0.897g Section 1613.2.3 (Eqn
16-20)
Site Class Modified MCER Spectral Response
Acceleration – (1 sec), SM1 0.409g 0.560g* Section 1613.2.3 (Eqn
16-21)
5% Damped Design
Spectral Response Acceleration (short), SDS 0.597g 0.598g Section 1613.2.4 (Eqn
16-22)
5% Damped Design
Spectral Response Acceleration (1 sec), SD1 0.272g 0.373g* Section 1613.2.4 (Eqn
16-23)
*See following paragraph.
11.3.2 Using the code-based values presented in this Table 7.3.1, in lieu of a performing a ground
motion hazard analysis, requires the exceptions outlined in ASCE 7-16 Section 11.4.8 be
followed by the project structural engineer. Per Section 11.4.8 of ASCE/SEI 7-16, a ground
motion hazard analysis should be performed for projects for Site Class “D” sites with S1
greater than 0.2g. Section 11.4.8 also provides exceptions which indicates that the ground
motion hazard analysis may be waived provided the exceptions are followed. Supplement 3
of ASCE 7-16 provides an exception stating that that the GMHA may be waived provided
that the parameter SM1 is increased by 50% for all applications of SM1. The values for
parameters SM1 and SD1 presented herein above have not been increased in accordance with
Supplement 3 of ASCE 7-16.
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Revised May 5, 2023
11.3.3 Table 11.3.2 presents the mapped maximum considered geometric mean (MCEG) seismic
design parameters for projects located in Seismic Design Categories of D through F in
accordance with ASCE 7-16.
TABLE 11.3.2
2022 CBC SITE ACCELERATION DESIGN PARAMETERS
Parameter Value ASCE 7-16
Site Class C D --
Fill Thickness, T (Feet) T<20 T>20 --
Mapped MCEGPeak Ground Acceleration, PGA 0.323g 0.323g Figure 22-7
Site Coefficient, FPGA 1.2 1.277 Table 11.8-1
Site Class Modified MCEG
Peak Ground Acceleration, PGAM 0.388g 0.413g Section 11.8.3 (Eqn 11.8-1)
11.3.4 Conformance to the criteria in Tables 11.3.1 and 11.3.2 for seismic design does not constitute
any kind of guarantee or assurance that significant structural damage or ground failure will
not occur in the event of a large earthquake. The primary goal of seismic design is to protect
life, not to avoid all damage, since such design may be economically prohibitive.
11.3.5 The project structural engineer and architect should evaluate the appropriate Risk Category
and Seismic Design Category for the planned structures. The values presented herein assume
a Risk Category of II and resulting in a Seismic Design Category D. Table 11.3.3 presents a
summary of the risk categories in accordance with ASCE 7-16.
TABLE 11.3.3
ASCE 7-16 RISK CATEGORIES
Risk Category Building Use Examples
I Low risk to Human Life at Failure Barn, Storage Shelter
II Nominal Risk to Human Life at Failure
(Buildings Not Designated as I, III or IV)
Residential, Commercial and Industrial
Buildings
III Substantial Risk to Human Life at
Failure
Theaters, Lecture Halls, Dining Halls,
Schools, Prisons, Small Healthcare
Facilities, Infrastructure Plants, Storage
for Explosives/Toxins
IV Essential Facilities
Hazardous Material Facilities,
Hospitals, Fire and Rescue, Emergency
Shelters, Police Stations, Power
Stations, Aviation Control Facilities,
National Defense, Water Storage
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Revised May 5, 2023
11.4 Slope Stability Analyses
11.4.1 We performed slope stability analyses using the computer software program GeoStudio 2018
to calculate the factor of safety with respect to deep-seated instability. This program uses
conventional slope stability equations and a two-dimensional, limit-equilibrium method. We
performed the rotational-mode and block-mode analyses using Spencer’s method. Output of
the computer program including the calculated Factor of Safety and the failure surface is
shown in Appendix A.
11.4.2 We used average drained direct shear strength parameters based on laboratory tests and our
experience with similar soil types in nearby areas. Our slope stability calculations indicate the
proposed cut and fill slopes, constructed of onsite materials, should have calculated factors of
safety of at least 1.5 under static conditions for both deep-seated failure and shallow sloughing
conditions if the recommendations of this report are followed. The shear strength parameters
used in the slope stability analyses are presented in Appendix A.
11.4.3 Based on the referenced grading plans, several MSE walls are planned on the property. Some
walls have heights of about 25. feet. Based on our experience, additional grid reinforcement
may be required for the walls to possess a factor of safety of at least 1.5. We should perform
global stability analyses of the walls prior to submittal of the retaining wall plans for the
planned development to evaluate required grid lengths.
11.4.4 We selected Geologic Cross-Sections A-A’ through H-H’ to perform the slope stability
analyses. The results and the computer output of the analyses are presented in Appendix A.
Table A-II provides a description of the cross-sections, their corresponding factor of safety,
and the condition of the slope stability analyses. A factor of safety of 1.5 for static conditions
is currently required by the City of Chula Vista for permanent graded slopes.
11.4.5 The placement of properly compacted fill will be required to stabilize weak bentonitic
claystone and siltstone layers expected to be encountered behind the proposed MSE retaining
wall on the east side of the property. In addition, a buttress fill will be required during grading
operations on the eastern portion of the site (See Geologic Cross-Sections E-E’, F-F’ and H-
H’) and next to Otay Valley Road (See Geologic Cross-Section D-D’) where bentonite will
be encountered in the slope zone during grading operations The buttresses will require
minimum widths ranging from 15 to 30 feet, as calculated. We will evaluate the length and
location of the buttress when the 40-scale grading plans have been prepared. A structural
setback would be required behind the buttress shown on Geologic Cross-Section F-F’, to keep
the required buttress within the limits of grading if the buttress was not installed during the
construction for the adjacent roadway.
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Revised May 5, 2023
11.4.6 Cut slopes within the upper member of the Otay Formation will require the construction of
stability fills to stabilize the slope face as discussed herein.
11.4.7 We performed surficial slope stability calculations for the planned slopes. The calculated
factor of safety is greater than the required minimum factor of safety of 1.5. Plants with
variable root depth should be planted as soon as practical once the fill slopes have been
constructed. Table 11.4 presents the surficial slope stability analysis for the proposed sloping
conditions. We assumed strengths for topsoil exposed at the slope surface.
TABLE 11.4
SURFICIAL SLOPE STABILITY EVALUATION
Parameter Value
Slope Height, H ∞
Vertical Depth of Saturation, Z 3 Feet
Slope Inclination, I (Horizontal to Vertical) 2:1 (26.6 Degrees)
Total Soil Unit Weight, γ 125 pcf
Water Unit Weight, γW 62.4 pcf
Friction Angle, 28 Degrees
Cohesion, C 250 psf
Factor of Safety = (C+(γ+γW )Zcos2I tan)/(γZsinI cosI) 2.2
11.4.8 Buttress and stability fill drains should be surveyed for location and elevation during
construction and depicted on the As-Graded Geologic Map in the final report of grading.
11.4.9 Excavations including cut slopes, shear keys and buttress and stability fills should be observed
during grading by an engineering geologist to evaluate whether soil and geologic conditions
do not differ significantly from those expected.
11.5 Grading
11.5.1 Grading should be performed in accordance with the attached Recommended Grading
Specifications contained in Appendix B and the City of Chula Vista Ordinance. Where the
recommendations of this section conflict with those of Appendix B, the recommendations of
this section shall take precedence. Earthwork should be observed and fill tested for dry density
and moisture content by Geocon Incorporated.
11.5.2 Prior to commencing grading, a preconstruction conference should be held at the site with the
city inspector, owner or developer, grading contractor, civil engineer, and geotechnical
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Revised May 5, 2023
engineer in attendance. Special soil handling and/or the grading plans can be discussed at that
time.
11.5.3 Site preparation should begin with the removal of deleterious material, debris and vegetation.
The depth of removal should be such that material exposed in cut areas or soil to be used as
fill is relatively free of organic matter. Material generated during stripping and/or site
demolition should be exported from the site.
11.5.4 Undocumented fill, topsoil and alluvium within the limits of grading should be removed to
expose firm Otay Formation or Terrace Deposits. The actual depth of removal should be
evaluated by the engineering geologist during grading operations. We do not expect that
removals will need to extend beyond the limits of grading. The bottom of the excavations
should be scarified to a depth of at least 1 foot, moisture conditioned as necessary, and
properly compacted. The upper 2 to 3 feet of previously placed fill will also require remedial
grading in the form of removal and recompaction. The remedial grading will be limited to the
area of proposed development and should not extend into the MSCP Preserve.
11.5.5 Bentonitic claystone layers that occur within 5 feet of finish grade should be removed and
replaced with properly compacted fill that possesses a “very low” to “medium” expansion
potential (EI of 90 or less). The undercut within the building pads should be sloped at least 2
percent toward the adjacent street or deep fill area.
11.5.6 Where bentonite claystone is encountered during grading operations, a buttress/stability fill
will be required. In addition, bentonite located within 5 feet of the planned finish grade
elevation should be removed and replaced with properly compacted fill. Bentonitic claystone
layers encountered during the normal excavation or undercutting of building pads, streets, or
slopes should be mixed with granular materials in a ratio of at least two parts sand to one part
bentonite clay and compacted to a dry density of at least 90 percent of the laboratory
maximum dry density at or slightly above optimum moisture. The mixed bentonite clay
should be placed at least 5 feet below finish grade, at least 15 feet from the face of a fill slope,
and not within buttress or stability fill slopes.
11.5.7 The upper 3 feet of cut lots should be over excavated and replaced with properly compacted
fill due to the very dense and cemented nature of the two members of the Otay Formation.
The bottom of the excavation should be sloped at least one percent toward the adjacent deeper
fill areas or adjacent roadways to reduce the potential for subsurface water to saturate fill
materials.
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Revised May 5, 2023
11.5.8 The City of Chula Vista has required that the upper 5 feet of fill soil and the upper 3 feet of
formational materials within the public right-of-way or public easement possess an expansion
index of 90 or less. If material with an expansion index greater than 90 exists within the right-
of-ways, the upper 5 feet of compacted fills and the upper 3 feet of formational should be
removed and replaced with fill with an expansion index of 90 or less or an alternative method
should be approved by the City of Chula Vista.
11.5.9 The undocumented fill existing within City of San Diego Otay 2nd and 3rd pipe should be
removed and replaced to competent formational materials within the existing easement to
design grades. The grading contractor should be careful not to damage the existing water lines
if they are left in place and operations during the grading operations. We expect the grading
would be limited to about 5 feet above the pipes and about 5 to 10 feet laterally from the pipes.
The contractor should provide the proper equipment and evaluation on excavations adjacent
to the pipelines. We can provide supplemental recommendations operations during the mass
grading operations as necessary.
11.5.10 If perched groundwater or saturated materials are encountered during remedial grading,
extensive drying and mixing with dryer soil will be required. This condition may potentially
occur within the canyon drainages, especially during the rainy season. The excavated
materials should then be moisture conditioned as necessary to near optimum moisture content
prior to placement as compacted fill.
11.5.11 We should observe the grading operations and the removal bottoms to check the exposure of
the formational materials prior to the placement of compacted fill. Deeper excavations may
be required if highly weathered formational materials are present at the base of the removals.
Fill soil should not be placed until we observe the bottom excavations. Table 11.5 provides a
summary of the grading recommendations.
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Revised May 5, 2023
TABLE 11.5.1
SUMMARY OF GRADING RECOMMENDATIONS
Area Removal Requirements
Undocumented Fill, Topsoil and Weathered
Formational Materials
Remove to Underlying, Dense Formational
Materials
Formation Within 3 Feet of Proposed Building
Pad Elevations Undercut 3 Feet Below Finish Grade
Bentonite Within 5 Feet of Proposed Grade Undercut 3 to 5 Feet Below Finish Grade of
Pad or Garages, whichever is Lower
Formation at Grade in Areas of Surface
Improvements Process Upper 1 to 2 Feet of Existing Materials
Lateral Grading Limits 10 Feet Outside of Buildings/2 Feet Outside of
Improvement Areas, Where Possible
Exposed Bottoms of Remedial Grading Scarify Upper 12 Inches
11.5.12 The site should be brought to finish grade elevations with fill compacted in layers. Layers of
fill should be no thicker than will allow for adequate bonding and compaction. Fill, including
backfill and scarified ground surfaces, should be compacted to a dry density of at least 90
percent of the laboratory maximum dry density near to slightly above optimum moisture
content in accordance with ASTM D 1557. Fill placed in excess of 40 feet from finish grade
should be compacted to a dry density of at least 92 percent of the laboratory maximum dry
density near to slightly above optimum moisture content. Fill materials placed below optimum
moisture content may require additional moisture conditioning prior to placing additional fill.
11.5.13 Topsoil should be handled in accordance with the soil remediation plan. Topsoil can be placed
at a depth of greater than 5 from subdrains and at least 10 feet from finish grades.
11.5.14 If additional rock fills are planned, in general, structural fill placed and compacted at the site
should consist of material that can be classified into four zones discussed in Table 11.5.2.
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Revised May 5, 2023
TABLE 11.5.2
ROCK FILL ZONES
Fill Zone Description
A
Material placed within 3 feet from building pad grade, 8 feet from roadway grade,
and to at least 2 feet below the deepest utility within roadways should consist of
“soil” fill with an approximate maximum particle dimension of 6 inches with a
minimum of 40 percent of the soil passing the ¾-inch sieve. In addition, the upper 3
feet of pad grade should have at least 20 percent of the soil passing the No. 4 sieve.
B
Material placed below 8 feet from grade (below Zone A and C) may consist of
“rock” fill or “soil/rock” fill (as defined in Appendix H). Blasted rock should
generally consist of 2-foot-minus rock material with occasional rock up to 4 feet in
maximum dimension. Alternatively, “soil” fill may be placed in Zone B containing
rock with a maximum dimension of 2 feet. Rocks up to 4 feet in maximum
dimension can be individually placed in a properly compacted soil matrix with rocks
separated at least 8 feet apart.
C
Within 3 to 8 feet of pad grade and between 5 and 15 feet from face of slope, fill
material should consist of “soil” fill with an approximate maximum particle
dimension of 1 foot. Rocks up to 2 feet in maximum dimension may be placed,
provided they are distributed in a matrix of compacted “soil” fill.
D Within the outer 5 feet of fill slopes, the fill should consist of rock up to 1 foot in
maximum dimension in a matrix of compacted “soil” fill.
11.5.15 Recommendations for the handling and disposal of oversized rock in fill areas are presented
in the Rock Disposal Detail and in Appendix H.
Oversize Rock Disposal Detail
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Revised May 5, 2023
11.5.16 Oversize rock placement should be performed in accordance with the Recommended Grading
Specifications provided in Appendix B. Blasting of rock material for the proposed sewer
should be performed to maximize rock breakage to 2-foot minus material, if necessary. Rock
fill placement should generally be limited to 2-foot-thick horizontal layers and compacted
using rock trucks and bulldozers. Significant volumes of water are typically required during
rock fill placement. The downstream areas can generate large volumes of water that can be
re-used during construction.
11.5.17 The construction of a buttress fill will be required on the east side of the property that will
expose bentonitic claystone or siltstone. Stability fills will be required where the
claystone/siltstone portion of the Otay Formation ins exposed in the slope faces. Cut slopes
located within the upper member of the Otay Formation (To) above an elevation of
approximately 370 feet MSL will require the construction of stability fills. The Typical
Stability Fill Detail should be used for design and construction of slope buttresses, where
required. The backcut for the buttress should commence at least 10 feet from the top of the
proposed finish-graded slope and should extend at least 3 feet below adjacent pad grade or
below the bentonite layer, to a maximum depth of 15 feet below finish-pad grade. The base
of the key should be slopes at least 5 percent to the drain, into slope.
Typical Stability Fill Detail
11.5.18 The slope backcut should be a 1:1 and in accordance with OSHA requirements. Chimney
drains should be installed along the backcut that are 4 feet wide, 20-foot on center and provide
dual-sided drainage. Closer spacing may be required where seepage is encountered. The
collector pipe at the base of the backcut should consists of a minimum 4-inch diameter,
perforated, Schedule 40 PVC pipe drained at a minimum of 1 percent. The pipe should be
surrounded by ¾-inch gravel wrapped in an approved filter fabric (Mirafi 140N or equivalent).
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Revised May 5, 2023
11.5.19 Cut slope excavations including buttresses and shear keys should be observed during grading
operations to check that soil and geologic conditions do not differ significantly from those
expected. During the construction of buttresses, there is a risk that the temporary backcut
slopes will becoming unstable if the timing between placement of drains and compacted fill
is not achieved. This risk can be reduced by grading the buttress fill in short segments,
reducing the timing of leaving a temporary condition, and/or flattening the inclination of the
temporary slope.
11.5.20 The outer 15 feet (or a distance equal to the height of the slope, whichever is less) of fill slopes
should be composed of properly compacted granular “soil” fill to reduce the potential for
surficial sloughing. In general, soil with an expansion index of 90 or less and at least
35 percent sand-size particles should be acceptable as “soil” fill. Soil of questionable strength
to satisfy surficial stability should be tested in the laboratory for acceptable drained shear
strength. The use of cohesionless soil in the outer portion of fill slopes should be avoided. Fill
slopes should be overbuilt at least 2 feet and cut back or be compacted by backrolling with a
loaded sheepsfoot roller at vertical intervals not to exceed 4 feet to maintain the moisture
content of the fill. The slopes should be track-walked at the completion of each slope such
that the fill is properly compacted to the face of the finished slope.
11.5.21 Finished slopes should be landscaped with drought-tolerant vegetation having variable root
depths and requiring minimal landscape irrigation. In addition, the slopes should be drained
and properly maintained to reduce erosion.
11.5.22 Import fill (if necessary) should consist of the characteristics presented in Table 11.5.3.
Geocon Incorporated should be notified of the import soil source and should perform
laboratory testing of import soil prior to its arrival at the site to determine its suitability as fill
material.
TABLE 11.5.3
SUMMARY OF IMPORT FILL RECOMMENDATIONS
Soil Characteristic Values
Expansion Potential “Very Low” to “Medium” (Expansion Index of 90 or less)
Particle Size Maximum Dimension Less Than 3 Inches
Generally Free of Debris
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Revised May 5, 2023
11.6 Earthwork Grading Factors
11.6.1 Estimates of bulking and shrinkage factors are based on empirical judgments comparing the
material in its natural state as encountered in the exploratory excavations to a compacted state.
Variations in natural soil density and in compacted fill density render shrinkage value
estimates very approximate. As an example, the contractor can compact the fill to a dry
density of 90 percent or higher of the laboratory maximum dry density. Thus, the contractor
has an approximately 10 percent range of control over the fill volume. Bulking of rock units
is a function of rock density, structure, overburden pressure, and the physical behavior of
blasted material. Based on our experience, the shrinkage and bulking factors presented in
Table 11.6 can be used as a basis for estimating how much the onsite soil may shrink or swell
(bulk) when excavated from their natural state and placed as compacted fill. Please note that
these estimates are for preliminary quantity estimates only. Due to the variations in the actual
shrinkage/bulking factors, a balance area that can also accommodate rock should be provided
to accommodate these variations.
TABLE 11.6
SHRINKAGE AND BULK FACTORS
Soil Unit Shrink/Bulk Factor
Surficial Soils (Qudf, topsoil, and Qal) 10% to 15% Shrink
Compacted and Previously Placed Fill (Qpf) 2% Shrink to 2% Bulk
Terrace Deposits 3% to 5% Bulk
Otay Formation (To and Tog) 4% to 8% Bulk
11.7 Subdrains
11.7.1 Conditions encountered prior to and during grading do not necessarily reveal the conditions
that will be encountered once construction of the proposed homes is completed. Specifically,
irrigation in up gradient areas cannot be reasonably predicted. Therefore, the design and
implementation of additional drainage mechanisms may be necessitated.The geologic units
encountered on the site have permeability characteristics and/or fracture systems that could
be susceptible under certain conditions to groundwater/seepage. The use of canyon subdrains
will be necessary to mitigate the potential for adverse impacts associated with seepage
conditions. The existing subdrain located at the toe of the fill slope along Rock Mountain
Road has been temporarily tied into an approved storm drain structure on Main Street East in
Village 8 West and will be removed during future grading operations. The following figure
presents a typical canyon subdrain detail.
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Revised May 5, 2023
Typical Canyon Subdrain Detail
11.7.2 Stability fill, buttress fill, and canyon subdrains should possess the dimensions presented in
Table 11.7. The Geologic Map, Figures 1 through 4 present the locations of proposed canyon
subdrains. The actual subdrain locations should be evaluated in the field during the mass
grading operations. The project civil engineer should survey the pipe locations and elevations
after installation. Appropriate subdrain outlets should be evaluated prior to finalizing 40-scale
grading plan.
TABLE 11.7
RECOMMENDED SUBDRAIN DIMENSIONS
Drain Size Drain Recommendations
4-Inch Schedule 40 PVC or Equivalent
Stability and Buttress Drains
6-Inch
Schedule 40 PVC (or Equivalent)
Less Than 100 Feet Deep
Less Than 500 Feet Long
8-Inch
Schedule 80 PVC (or Equivalent)
Greater Than 100 Feet Deep
Greater Than 500 Feet Long
11.7.3 Prior to outletting, the final 20-foot segment of a subdrain that will not be extended during
future development should consist of non-perforated drainpipe. At the non-
perforated/perforated interface, a seepage cutoff wall should be constructed on the downslope
side of the junction as shown herein.
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Revised May 5, 2023
Typical Cutoff Wall Detail
11.7.4 Subdrains that discharge into a natural drainage course or open space area should be provided
with a permanent headwall structure as shown herein.
Typical Headwall Detail
11.7.5 Building pad areas adjacent to large ascending slopes may experience wet to saturated soil
conditions due to water migration or seepage. To reduce the potential for this to occur,
consideration should be given to placing a subdrain along the base of the slopes to collect
potential seepage and convey it to a suitable outlet. The pad subdrain should be sufficiently
deep to intercept the seepage (on the order of 3 feet below finish grade) and constructed in
accordance with the recommendations in the subdrain section of this report. The necessity for
the drains should be discussed prior to grading on a slope specific basis. In addition, the
project civil engineer should be consulted to evaluate the appropriate drain locations and
necessary easements, building restriction zones or disclosure requirements that may be
necessary. The pad subdrains should be surveyed for location and shown on the project as-
built drawings.
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Revised May 5, 2023
11.7.6 The final grading plans should show the location of the proposed subdrains. Upon completion
of remedial excavations and subdrain installation, the project civil engineer should survey the
drain locations and prepare an “as-built” map depicting the existing conditions. The final
outlet and connection locations should be determined during grading. Subdrains that will be
extended on adjacent projects shortly after grading can be placed on formational material and
a vertical riser should be placed at the end of the subdrain. The grading contractor should
consider videoing the subdrains shortly after burial to check proper installation and to check
that the pipe has not been crushed. The contractor is responsible for the performance of the
drains.
11.8 Preliminary Foundation and Concrete Slabs-On-Grade Recommendations
11.8.1 The foundation recommendations herein are for the proposed residential structures. The
foundation recommendations have been separated into three categories based on the
maximum and differential fill thickness and expansion index. Table 11.8.1 presents the
foundation category criteria. Based on review of the laboratory test results performed during
previous grading, we expect majority of the soil encountered on site is planned to possess a
“very low” to “medium” expansion potential (expansion index of 90 or less). Recommended
foundation categories for the subject building pads will be provided after fine grading is
completed and we re-evaluate the expansion index of the fill material in the upper 3 to 4 feet
during the regrading operations.
TABLE 11.8.1
FOUNDATION CATEGORY CRITERIA
Foundation
Category
Maximum Fill
Thickness, T (Feet)
Differential Fill
Thickness, D (Feet) Expansion Index (EI)
I T<20 -- EI<50
II 20<T<50 10<D<20 50<EI<90
III T>50 D>20 90<EI<130
11.8.2 Table 11.8.2 presents minimum foundation and interior concrete slab design criteria for
conventional foundation systems. The grading of building pads should be such that the upper
3 feet of finish grade soils should have an expansion index of 90 or less, where possible.
However, the recommendations presented herein incorporates finish grade soil with an
expansion index of up to 130.
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Revised May 5, 2023
TABLE 11.8.2
CONVENTIONAL FOUNDATION RECOMMENDATIONS BY CATEGORY
Foundation
Category
Minimum Footing
Embedment
Depth, D (inches)
Minimum Continuous
Footing
Reinforcement
Minimum Footing
Width (Inches)
I 12 Two No. 4 bars, one top
and one bottom
12 – Continuous, WC
24 – Isolated, WI
II 18 Four No. 4 bars, two top
and two bottom
III 24 Four No. 5 bars, two top
and two bottom
11.8.3 The embedment depths presented in Table 11.8.2 should be measured from the lowest
adjacent pad grade for both interior and exterior footing. The foundations should be embedded
in accordance with the recommendations herein and the Wall/Column Footing Dimension
Detail. The embedment depths should be measured from the lowest adjacent pad grade for
both interior and exterior footings. Footings should be deepened such that the bottom outside
edge of the footing is at least 7 feet horizontally from the face of the slope (unless designed
with a post-tensioned foundation system as discussed herein).
Wall/Column Footing Dimension Detail
11.8.4 We will provide final foundation categories for each building or lot after finish pad grades
have been achieved and we perform laboratory testing of the subgrade soil.
11.8.5 Table 11.8.3 presents minimum foundation and interior concrete slab design criteria for
conventional foundation systems.
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Revised May 5, 2023
11.8.6 The proposed structures can be supported on a shallow foundation system founded in the
compacted fill/formational materials. Table 11.8.3 provides a summary of the foundation
design recommendations.
TABLE 11.8.3
SUMMARY OF FOUNDATION RECOMMENDATIONS
Parameter Value
Allowable Bearing Capacity 2,000 psf
Estimated Total Settlement 1 Inch
Estimated Differential Settlement ½ Inch in 40 Feet
11.8.7 The bearing capacity values presented herein are for dead plus live loads and may be increased
by one-third when considering transient loads due to wind or seismic forces.
11.8.8 The concrete slab-on-grade should be a minimum of 4 inches thick for Foundation Categories
I and II and 5 inches thick for Foundation Category III.
11.8.9 Slabs that may receive moisture-sensitive floor coverings or may be used to store moisture-
sensitive materials should be underlain by a vapor retarder. The vapor retarder design should
be consistent with the guidelines presented in the American Concrete Institute’s (ACI) Guide
for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials (ACI 302.2R-06). In
addition, the membrane should be installed in accordance with manufacturer’s
recommendations and ASTM requirements and installed in a manner that prevents puncture.
The vapor retarder used should be specified by the project architect or developer based on the
type of floor covering that will be installed and if the structure will possess a humidity-
controlled environment.
11.8.10 The bedding sand thickness should be determined by the project foundation engineer,
architect, and/or developer. However, we should be contacted to provide recommendations if
the bedding sand is thicker than 6 inches. It is common to see 3 inches and 4 inches of sand
below the concrete slab-on-grade for 5-inch and 4-inch thick slabs, respectively, in the
southern California area. The foundation design engineer should provide appropriate concrete
mix design criteria and curing measures to assure proper curing of the slab by reducing the
potential for rapid moisture loss and subsequent cracking and/or slab curl. We suggest that
the foundation design engineer present the concrete mix design and proper curing methods on
the foundation plans. It is critical that the foundation contractor understands and follows the
recommendations presented on the foundation plans.
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Revised May 5, 2023
11.8.11 As an alternative to the conventional foundation recommendations, consideration should be
given to the use of post-tensioned concrete slab and foundation systems for the support of the
proposed structures. If a post-tensioned system is being used, the proposed buildings would be
designated with a Foundation Category once grading is completed. The post-tensioned systems
should be designed by a structural engineer experienced in post-tensioned slab design and design
criteria of the Post-Tensioning Institute (PTI) DC 10.5-12 Standard Requirements for Design
and Analysis of Shallow Post-Tensioned Concrete Foundations on Expansive Soils or WRI/CRSI
Design of Slab-on-Ground Foundations, as required by the 2019 California Building Code
(CBC Section 1808.6.2). Although this procedure was developed for expansive soil conditions,
it can also be used to reduce the potential for foundation distress due to differential fill
settlement. The post-tensioned design should incorporate the geotechnical parameters presented
in Table 11.8.4 for the particular Foundation Category designated. The parameters presented in
Table 11.8.4 are based on the guidelines presented in the PTI DC 10.5 design manual.
TABLE 11.8.4
POST-TENSIONED FOUNDATION SYSTEM DESIGN PARAMETERS
Post-Tensioning Institute (PTI) DC10.5 Design
Parameters
Foundation Category
I II III
Thornthwaite Index -20 -20 -20
Equilibrium Suction 3.9 3.9 3.9
Edge Lift Moisture Variation Distance, eM (Feet) 5.3 5.1 4.9
Edge Lift, yM (Inches) 0.61 1.10 1.58
Center Lift Moisture Variation Distance, eM (Feet) 9.0 9.0 9.0
Center Lift, yM (Inches) 0.30 0.47 0.66
11.8.12 The foundations for the post-tensioned slabs should be embedded in accordance with the
recommendations of the structural engineer. If a post-tensioned mat foundation system is
planned, the slab should possess a thickened edge with a minimum width of 12 inches and
extend below the clean sand or crushed rock layer.
11.8.13 If the structural engineer proposes a post-tensioned foundation design method other than PTI,
DC 10.5:
The deflection criteria presented in Table 11.8.4 are still applicable.
Interior stiffener beams should be used for Foundation Categories II and III.
The width of the perimeter foundations should be at least 12 inches.
The perimeter footing embedment depths should be at least 12 inches, 18 inches and
24 inches for foundation categories I, II, and III, respectively. The embedment depths
should be measured from the lowest adjacent pad grade.
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Revised May 5, 2023
11.8.14 Foundation systems for the lots that possess a foundation Category I and a “very low”
expansion potential (expansion index of 20 or less) can be designed using the method
described in Section 1808 of the 2022 CBC. If post-tensioned foundations are planned, an
alternative, commonly accepted design method (other than PTI) can be used. However, the
post-tensioned foundation system should be designed with a total and differential deflection
of 1 inch. Geocon Incorporated should be contacted to review the plans and provide additional
information, if necessary.
11.8.15 If an alternate design method is contemplated, Geocon Incorporated should be contacted to
evaluate if additional expansion index testing should be performed to identify the lots that
possess a “very low” expansion potential (expansion index of 20 or less).
11.8.16 Our experience indicates post-tensioned slabs may be susceptible to excessive edge lift from
tensioning, regardless of the underlying soil conditions. Placing reinforcing steel at the bottom
of the perimeter footings and the interior stiffener beams may mitigate this potential. The
structural engineer should design the foundation system to reduce the potential of edge lift
occurring for the proposed structures.
11.8.17 During the construction of the post-tension foundation system, the concrete should be placed
monolithically. Under no circumstances should cold joints form between the footings/grade
beams and the slab during the construction of the post-tension foundation system unless
designed by the structural engineer.
11.8.18 Isolated footings outside of the slab area, if present, should have the minimum embedment
depth and width recommended for conventional foundations for a particular Foundation
Category. The use of isolated footings, which are located beyond the perimeter of the building
and support structural elements connected to the building, are not recommended for Category
III. Where this condition cannot be avoided, the isolated footings should be connected to the
building foundation system with grade beams. In addition, consideration should be given to
connecting patio slabs, which exceed 5 feet in width, to the building foundation to reduce the
potential for future separation to occur.
11.8.19 Interior stiffening beams should be incorporated into the design of the foundation system in
accordance with the PTI design procedures.
11.8.20 Special subgrade presaturation is not deemed necessary prior to placing concrete; however,
the exposed foundation and slab subgrade soil should be moisture conditioned, as necessary,
to maintain a moist condition as would be expected in any such concrete placement.
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Revised May 5, 2023
11.8.21 Where buildings or other improvements are planned near the top of a slope 3:1
(horizontal:vertical) or steeper, special foundation and/or design considerations are
recommended due to the tendency for lateral soil movement to occur.
For fill slopes less than 20 feet high or cut slopes regardless of height, footings should
be deepened such that the bottom outside edge of the footing is at least 7 feet
horizontally from the face of the slope.
When located next to a descending 3:1 (horizontal:vertical) fill slope or steeper, the
foundations should be extended to a depth where the minimum horizontal distance is
equal to H/3 (where H equals the vertical distance from the top of the fill slope to the
base of the fill soil) with a minimum of 7 feet but need not exceed 40 feet. The
horizontal distance is measured from the outer, deepest edge of the footing to the face
of the slope. A post-tensioned slab and foundation system or mat foundation system
can be used to reduce the potential for distress in the structures associated with strain
softening and lateral fill extension. Specific design parameters or recommendations
for either of these alternatives can be provided once the building location and fill
slope geometry have been determined.
If swimming pools are planned, Geocon Incorporated should be contacted for a
review of specific site conditions.
Swimming pools located within 7 feet of the top of cut or fill slopes are not
recommended. Where such a condition cannot be avoided, the portion of the
swimming pool wall within 7 feet of the slope face be designed assuming that the
adjacent soil provides no lateral support. This recommendation applies to fill
slopes up to 30 feet in height, and cut slopes regardless of height. For swimming
pools located near the top of fill slopes greater than 30 feet in height, additional
recommendations may be required and Geocon Incorporated should be contacted for
a review of specific site conditions.
Although other improvements, which are relatively rigid or brittle, such as concrete
flatwork or masonry walls, may experience some distress if located near the top of a
slope, it is generally not economical to mitigate this potential. It may be possible,
however, to incorporate design measures which would permit some lateral soil
movement without causing extensive distress. Geocon Incorporated should be
consulted for specific recommendations.
11.8.22 The recommendations of this report are intended to reduce the potential for cracking of slabs
and foundations due to expansive soil (if present), differential settlement of fill soil with
varying thicknesses. However, even with the incorporation of the recommendations presented
herein, foundations, stucco walls, and slabs-on-grade placed on such conditions may still
exhibit some cracking due to soil movement and/or shrinkage. The occurrence of concrete
shrinkage cracks is independent of the supporting soil characteristics. Their occurrence may
be reduced by limiting the slump of the concrete, proper concrete placement and curing, and
Geocon Project No. G1006-52-05 - 39 - September 30, 2022
Revised May 5, 2023
by the placement of crack control joints at periodic intervals, in particular, where re-entrant
slab corners occur.
11.8.23 Concrete slabs should be provided with adequate crack-control joints, construction joints
and/or expansion joints to reduce unsightly shrinkage cracking. The design of joints should
consider criteria of the American Concrete Institute when establishing crack-control spacing.
Additional steel reinforcing, concrete admixtures and/or closer crack control joint spacing
should be considered where concrete-exposed finished floors are planned.
11.8.24 Geocon Incorporated should be consulted to provide additional design parameters as required
by the structural engineer.
11.8.25 We should observe the foundation excavations prior to the placement of reinforcing steel to
check that the exposed soil conditions are similar to those expected and that they have been
extended to the appropriate bearing strata. If unexpected soil conditions are encountered,
foundation modifications may be required.
11.9 Exterior Concrete Flatwork
11.9.1 Exterior concrete flatwork not subject to vehicular traffic should be constructed in accordance
with the recommendations presented in Table 11.9. The recommended steel reinforcement
would help reduce the potential for cracking.
TABLE 11.9
MINIMUM CONCRETE FLATWORK RECOMMENDATIONS
Expansion
Index, EI Minimum Steel Reinforcement* Options Minimum
Thickness
EI < 90 6x6-W2.9/W2.9 (6x6-6/6) welded wire mesh 4 Inches No. 3 Bars 18 inches on center, Both Directions
EI < 130 4x4-W4.0/W4.0 (4x4-4/4) welded wire mesh 4 Inches No. 4 Bars 12 inches on center, Both Directions
*In excess of 8 feet square.
11.9.2 The subgrade soil should be properly moisturized and compacted prior to the placement of
steel and concrete. The subgrade soil should be compacted to a dry density of at least 90
percent of the laboratory maximum dry density near to slightly above optimum moisture
content in accordance with ASTM D 1557.
Geocon Project No. G1006-52-05 - 40 - September 30, 2022
Revised May 5, 2023
11.9.3 Even with the incorporation of the recommendations of this report, the exterior concrete
flatwork has a potential to experience some uplift due to expansive soil beneath grade. The
steel reinforcement should overlap continuously in flatwork to reduce the potential for vertical
offsets within flatwork. Additionally, flatwork should be structurally connected to the curbs,
where possible, to reduce the potential for offsets between the curbs and the flatwork.
11.9.4 Where exterior flatwork abuts the structure at entrant or exit points, the exterior slab should
be dowelled into the structure’s foundation stemwall. This recommendation is intended to
reduce the potential for differential elevations that could result from differential settlement or
minor heave of the flatwork. Dowelling details should be designed by the project structural
engineer.
11.9.5 The recommendations presented herein are intended to reduce the potential for cracking of
exterior slabs as a result of differential movement. However, even with the incorporation of
the recommendations presented herein, slabs-on-grade will still crack. The occurrence of
concrete shrinkage cracks is independent of the soil supporting characteristics. Their
occurrence may be reduced and/or controlled by limiting the slump of the concrete, the use of
crack control joints and proper concrete placement and curing. Crack control joints should be
spaced at intervals no greater than 12 feet. Literature provided by the Portland Concrete
Association (PCA) and American Concrete Institute (ACI) present recommendations for
proper concrete mix, construction, and curing practices, and should be incorporated into
project construction.
11.10 Conventional Retaining Walls
11.10.1 Retaining walls should be designed using the values presented in Table 11.10.1. Soil with an
expansion index (EI) of greater than 90 should not be used as backfill material behind
retaining walls.
TABLE 11.10.1
RETAINING WALL DESIGN RECOMMENDATIONS
Parameter Value
Active Soil Pressure, A (Fluid Density, Level Backfill) 40 pcf
Active Soil Pressure, A (Fluid Density, 2:1 Sloping Backfill) 55 pcf
Restrained Walls Additional Uniform Pressure (0 to 8 Feet High) 7H psf
Restrained Walls Additional Uniform Pressure (8+ Feet High) 13H psf
Seismic Pressure 15H psf
Expected Expansion Index for the Subject Property EI<90
H equals the height of the retaining portion of the wall
Geocon Project No. G1006-52-05 - 41 - September 30, 2022
Revised May 5, 2023
11.10.2 The project retaining walls should be designed as shown in the Retaining Wall Loading
Diagram.
Retaining Wall Loading Diagram
11.10.3 Unrestrained walls are those that are allowed to rotate more than 0.001H (where H equals the
height of the retaining portion of the wall) at the top of the wall. Where walls are restrained
from movement at the top (at-rest condition), an additional uniform pressure should be added
to the active soil pressure for walls. For retaining walls subject to vehicular loads within a
horizontal distance equal to two-thirds the wall height, a surcharge equivalent to 2 feet of fill
soil should be added.
11.10.4 The structural engineer should determine the Seismic Design Category for the project in
accordance with Section 1613 of the 2022 CBC or Section 11.6 of ASCE 7-10. For structures
assigned to Seismic Design Category of D, E, or F, retaining walls that support more than 6
feet of backfill should be designed with seismic lateral pressure in accordance with Section
1803.5.12 of the 2022 CBC. The seismic load is dependent on the retained height where H is
the height of the wall, in feet, and the calculated loads result in pounds per square foot (psf)
exerted at the base of the wall and zero at the top of the wall.
11.10.5 Retaining walls should be designed to ensure stability against overturning sliding, and
excessive foundation pressure. Where a keyway is extended below the wall base with the
intent to engage passive pressure and enhance sliding stability, it is not necessary to consider
active pressure on the keyway.
Geocon Project No. G1006-52-05 - 42 - September 30, 2022
Revised May 5, 2023
11.10.6 Drainage openings through the base of the wall (weep holes) should not be used where the
seepage could be a nuisance or otherwise adversely affect the property adjacent to the base of
the wall. The recommendations herein assume a properly compacted granular (EI of 90 or
less) free draining backfill material with no hydrostatic forces or imposed surcharge load. The
retaining wall should be properly drained as shown in the Typical Retaining Wall Drainage
Detail. If conditions different than those described are expected, or if specific drainage details
are desired, Geocon Incorporated should be contacted for additional recommendations.
Typical Retaining Wall Drainage Detail
11.10.7 The retaining walls may be designed using either the active and restrained (at-rest) loading
condition or the active and seismic loading condition as suggested by the structural engineer.
Typically, it appears the design of the restrained condition for retaining wall loading may be
adequate for the seismic design of the retaining walls. However, the active earth pressure
combined with the seismic design load should be reviewed and also considered in the design
of the retaining walls.
11.10.8 In general, wall foundations having should be designed in accordance with Table 11.10.2. The
proximity of the foundation to the top of a slope steeper than 3:1 could impact the allowable
soil bearing pressure. Therefore, retaining wall foundations should be deepened such that the
bottom outside edge of the footing is at least 7 feet horizontally from the face of the slope.
TABLE 11.10.2
SUMMARY OF RETAINING WALL FOUNDATION RECOMMENDATIONS
Parameter Value
Minimum Retaining Wall Foundation Width 12 inches
Minimum Retaining Wall Foundation Depth 12 Inches
Minimum Steel Reinforcement Per Structural Engineer
Allowable Bearing Capacity 2,000 psf
Estimated Total Settlement From Footing Loads 1 Inch
Estimated Differential Settlement From Footing Loads ½ Inch in 40 Feet
Geocon Project No. G1006-52-05 - 43 - September 30, 2022
Revised May 5, 2023
11.10.9 The recommendations presented herein are generally applicable to the design of rigid concrete
or masonry retaining walls. In the event that other types of walls (such as mechanically
stabilized earth [MSE] walls, soil nail walls, or soldier pile walls) are planned, Geocon
Incorporated should be consulted for additional recommendations.
11.10.10 Unrestrained walls will move laterally when backfilled and loading is applied. The amount of
lateral deflection is dependent on the wall height, the type of soil used for backfill, and loads
acting on the wall. The retaining walls and improvements above the retaining walls should be
designed to incorporate an appropriate amount of lateral deflection as determined by the
structural engineer.
11.10.11 Soil contemplated for use as retaining wall backfill, including import materials, should be
identified in the field prior to backfill. At that time, Geocon Incorporated should obtain
samples for laboratory testing to evaluate its suitability. Modified lateral earth pressures may
be necessary if the backfill soil does not meet the required expansion index or shear strength.
City or regional standard wall designs, if used, are based on a specific active lateral earth
pressure and/or soil friction angle. In this regard, on-site soil to be used as backfill may or
may not meet the values for standard wall designs. Geocon Incorporated should be consulted
to assess the suitability of the on-site soil for use as wall backfill if standard wall designs will
be used.
11.11 Lateral Loading
11.11.1 Table 11.11 should be used to help design the proposed structures and improvements to resist
lateral loads for the design of footings or shear keys. The allowable passive pressure assumes
a horizontal surface extending at least 5 feet, or three times the surface generating the passive
pressure, whichever is greater. The upper 12 inches of material in areas not protected by floor
slabs or pavement should not be included in design for passive resistance.
TABLE 11.11
SUMMARY OF LATERAL LOAD DESIGN RECOMMENDATIONS
Parameter Value
Passive Pressure Fluid Density 350 pcf
Coefficient of Friction (Concrete and Soil) 0.35
Coefficient of Friction (Along Vapor Barrier) 0.2 to 0.25*
*Per manufacturer’s recommendations.
Geocon Project No. G1006-52-05 - 44 - September 30, 2022
Revised May 5, 2023
11.11.2 The passive and frictional resistant loads can be combined for design purposes. The lateral
passive pressures may be increased by one-third when considering transient loads due to wind
or seismic forces.
11.12 Preliminary Pavement Recommendations
11.12.1 We calculated the flexible pavement sections in general conformance with the Caltrans
Method of Flexible Pavement Design (Highway Design Manual, Section 608.4) using an
estimated Traffic Index (TI) of 5.0, 6.0, 7.5, 8.0 and 8.5 for the planned roadways in
accordance with the City of Chula Vista Subdivision Manual Section 3-400 (2012). The final
pavement sections for roadways should be based on the R-Value of the subgrade soils
encountered at final subgrade elevation. Streets should be designed in accordance with the
City of Chula specifications when final Traffic Indices and R-Value test results of subgrade
soil are completed. Based on the results of our laboratory R-Value testing, we used an R-
Value of 15 for the subgrade soil for the purposes of this preliminary analysis. Table 11.12.1
presents the preliminary flexible pavement sections. The City of Chula Vista will likely
provide the required pavement section thicknesses subsequent to reviewing laboratory R-
Values once the utilities have been installed.
TABLE 11.12.1
PRELIMINARY FLEXIBLE PAVEMENT SECTION
Location Assumed
Traffic Index
Assumed
Subgrade
R-Value
Asphalt
Concrete
(inches)
Aggregate
Base (inches)
Residential Cul-De-Sac 5.0 15 3 8
Residential 6.0 15 3.5 11
Class III Collector 7.0 15 4 13
Class II Collector (Secondary
Village Entry) 8.0 15 5 15
Class I Collector (Village
Entry) 8.5 15 5 17
11.12.2 Prior to placing base materials, the upper 12 inches of the subgrade soil should be scarified,
moisture conditioned as necessary, and recompacted to a dry density of at least 95 percent of
the laboratory maximum dry density near to slightly above optimum moisture content as
determined by ASTM D 1557. Similarly, the base material should be compacted to a dry
density of at least 95 percent of the laboratory maximum dry density near to slightly above
optimum moisture content. Asphalt concrete should be compacted to a density of at least 95
percent of the laboratory Hveem density in accordance with ASTM D 2726.
Geocon Project No. G1006-52-05 - 45 - September 30, 2022
Revised May 5, 2023
11.12.3 The crushed aggregate base materials and asphalt concrete should conform to the Standard
Specifications for Public Works Construction (Greenbook) and the City of Chula Vista
Standard Special Provisions.
11.12.4 The base thickness can be reduced if a reinforcement geogrid is used during the installation
of the pavement. Geocon should be contact for additional recommendations, if required.
11.12.5 A rigid Portland cement concrete (PCC) pavement section should be placed in driveway
entrance aprons, trash bin loading/storage areas and loading dock areas. The concrete pad for
trash truck areas should be large enough such that the truck wheels will be positioned on the
concrete during loading. We calculated the rigid pavement section in general conformance
with the procedure recommended by the American Concrete Institute report ACI 330-21
Commercial Concrete Parking Lots and Site Paving Design and Construction – Guide.
Table 11.12.2 provides the traffic categories and design parameters used for the calculations
for 20-year design life.
TABLE 11.12.2
TRAFFIC CATEGORIES
Traffic
Category Description Reliability
(%)
Slabs Cracked at End
of Design Life (%)
A Car Parking Areas and Access Lanes 60 15
B Entrance and Truck Service Lanes 60 15
E Garbage or Fire Truck Lane 75 15
11.12.6 We used the parameters presented in Table 11.12.3 to calculate the pavement design sections.
We should be contacted to provide updated design sections, if necessary.
TABLE 11.12.3
RIGID PAVEMENT DESIGN PARAMETERS
Design Parameter Design Value
Modulus of subgrade reaction, k 100 pci
Modulus of rupture for concrete, MR 500 psi
Concrete Compressive Strength 3,000 psi
Concrete Modulus of Elasticity, E 3,150,000
11.12.7 Based on the criteria presented herein, the PCC pavement sections should have a minimum
thickness as presented in Table 11.12.4.
Geocon Project No. G1006-52-05 - 46 - September 30, 2022
Revised May 5, 2023
TABLE 11.12.4
RIGID PAVEMENT RECOMMENDATIONS
Location Portland Cement
Concrete (inches)
Parking Stalls (TC=A) 6
Driveways, Alleyways, and Heavy Truck and Fire Lane Areas (TC=C) 7
11.12.8 The PCC vehicular pavement should be placed over subgrade soil that is compacted to a dry
density of at least 95 percent of the laboratory maximum dry density near to slightly above
optimum moisture content.
11.12.9 Adequate joint spacing should be incorporated into the design and construction of the rigid
pavement in accordance with Table 11.12.5.
TABLE 11.12.5
MAXIMUM JOINT SPACING
Pavement Thickness, T (Inches) Maximum Joint Spacing (Feet)
4<T<5 10
5<T<6 12.5
6<T 15
11.12.10 The rigid pavement should also be designed and constructed incorporating the parameters
presented in Table 11.12.6.
TABLE 11.12.6
ADDITIONAL RIGID PAVEMENT RECOMMENDATIONS
Subject Value
Thickened Edge
1.2 Times Slab Thickness Adjacent to Structures
1.5 Times Slab Thickness Adjacent to Soil
Minimum Increase of 2 Inches
4 Feet Wide
Crack Control Joint
Depth
Early Entry Sawn = T/6 to T/5, 1.25 Inch Minimum
Conventional (Tooled or Conventional Sawing) = T/4 to T/3
Crack Control Joint
Width
¼-Inch for Sealed Joints and Per Sealer Manufacturer’s
Recommendations
1/16- to 1/4-Inch is Common for Unsealed Joints
Geocon Project No. G1006-52-05 - 47 - September 30, 2022
Revised May 5, 2023
11.12.11 Reinforcing steel will not be necessary within the concrete for geotechnical purposes with the
possible exception of dowels at construction joints as discussed herein.
11.12.12 To control the location and spread of concrete shrinkage cracks, crack-control joints
(weakened plane joints) should be included in the design of the concrete pavement slab.
Crack-control joints should not exceed 30 times the slab thickness with a maximum spacing
of 15 feet for the 7-inch-thick slabs and should be sealed with an appropriate sealant to prevent
the migration of water through the control joint to the subgrade materials. The depth of the
crack-control joints should be determined by the referenced ACI report.
11.12.13 To provide load transfer between adjacent pavement slab sections, a butt-type construction
joint should be constructed. The butt-type joint should be thickened by at least 20 percent at the
edge and taper back at least 4 feet from the face of the slab. As an alternative to the butt-type
construction joint, dowelling can be used between construction joints for pavements of 7 inches
or thicker. As discussed in the referenced ACI guide, dowels should consist of smooth, 1-inch-
diameter reinforcing steel 14 inches long embedded a minimum of 6 inches into the slab on either
side of the construction joint. Dowels should be located at the midpoint of the slab, spaced at 12
inches on center and lubricated to allow joint movement while still transferring loads. In addition,
tie bars should be installed at the as recommended in Section 3.8.3 of the referenced ACI guide.
The structural engineer should provide other alternative recommendations for load transfer.
11.13 Slope Maintenance
11.13.1 Slopes that are steeper than 3:1 (horizontal to vertical) may, under conditions which are both
difficult to prevent and predict, be susceptible to near surface (surficial) slope instability. The
instability is typically limited to the outer three feet of a portion of the slope and usually does
not directly impact the improvements on the pad areas above or below the slope. The
occurrence of surficial instability is more prevalent on fill slopes and is generally preceded by
a period of heavy rainfall, excessive irrigation, or the migration of subsurface seepage. The
disturbance and/or loosening of the surficial soils, as might result from root growth, soil
expansion, or excavation for irrigation lines and slope planting, may also be a significant
contributing factor to surficial instability. It is, therefore, recommended that, to the maximum
extent practical: (a) disturbed/loosened surficial soils be either removed or properly
recompacted, (b) irrigation systems be periodically inspected and maintained to eliminate
leaks and excessive irrigation, and (c) surface drains on and adjacent to slopes be periodically
maintained to preclude ponding or erosion. It should be noted that although the incorporation
of the recommendations herein should reduce the potential for surficial slope instability, it
will not eliminate the possibility, and, therefore, it may be necessary to rebuild or repair a
portion of the project's slopes in the future.
Geocon Project No. G1006-52-05 - 48 - September 30, 2022
Revised May 5, 2023
11.13.2 To help mitigate slope creep from occurring, plants with variable root depth should be
installed soon after the construction of the slopes. In addition, rodent abatement is also
important as part of the slope maintenance.
11.13.3 The planned buildings and structures should be setback in accordance with CBC Section 18
and as recommended herein. Some mitigation measures could include not placing large
exterior concrete slabs at the top of the slopes but installing bands of concrete that would
allow some lateral movements. Also, pilasters from walls could be separated from the walls
to allow some lateral movement without damaging the walls.
11.13.4 The soil creep zone is usually isolated to the outer 5 to 10 feet of the slope face. The planned
residential structures and improvements are not planned within this zone. Foundation
recommendations for walls located adjacent to slopes are provided in the foundation section
of this report. However, if planned retaining walls or similar improvements that are prone to
creeping are proposed at the top of slopes, we would recommend that deepened footings be
incorporated to help reduce the effect of lateral fill extension.
11.14 Site Drainage and Moisture Protection
11.14.1 Adequate site drainage is critical to reduce the potential for differential soil movement,
erosion and subsurface seepage. Under no circumstances should water be allowed to pond
adjacent to footings. The site should be graded and maintained such that surface drainage is
directed away from structures in accordance with 2022 CBC 1804.4 or other applicable
standards. In addition, surface drainage should be directed away from the top of slopes into
swales or other controlled drainage devices. Roof and pavement drainage should be directed
into conduits that carry runoff away from the proposed structure.
11.14.2 In the case of basement walls or building walls retaining landscaping areas, a water-proofing
system should be used on the wall and joints, and a Miradrain drainage panel (or similar)
should be placed over the waterproofing. The project architect or civil engineer should
provide detailed specifications on the plans for all waterproofing and drainage.
11.14.3 Underground utilities should be leak free. Utility and irrigation lines should be checked
periodically for leaks, and detected leaks should be repaired promptly. Detrimental soil
movement could occur if water is allowed to infiltrate the soil for prolonged periods of time.
11.14.4 If detention basins, bioswales, retention basins, water infiltration, low impact development
(LID), or storm water management devices are being considered, Geocon Incorporated should
Geocon Project No. G1006-52-05 - 49 - September 30, 2022
Revised May 5, 2023
be retained to provide recommendations pertaining to the geotechnical aspects of possible
impacts and design.
11.14.5 If not properly constructed, there is a potential for distress to improvements and properties
located hydrologically down gradient or adjacent to these devices. Factors such as the amount
of water to be detained, its residence time, and soil permeability have an important effect on
seepage transmission and the potential adverse impacts that may occur if the storm water
management features are not properly designed and constructed. Based on our experience
with similar clayey soil conditions, infiltration areas are considered infeasible due to the poor
percolation and lateral migration characteristics. We have not performed a hydrogeology
study at the site. Down-gradient and adjacent structures may be subjected to seeps, movement
of foundations and slabs, or other impacts as a result of water infiltration.
11.15 Grading and Foundation Plan Review
11.15.1 Geocon Incorporated should review the final grading and foundation plans prior to
finalization to check their compliance with the recommendations of this report and evaluate
the need for additional comments, recommendations, and/or analyses.
11.16 Testing and Observation Services During Construction
11.16.1 Geocon Incorporated should provide geotechnical testing and observation services during the
grading operations, foundation construction, utility installation, retaining wall backfill and
pavement installation. Table 11.16 presents the typical geotechnical observations we would
expect for the proposed improvements.
TABLE 11.16
EXPECTED GEOTECHNICAL TESTING AND OBSERVATION SERVICES
Construction Phase Observations Expected Time Frame
Grading
Base of Removal Part Time During
Removals
Geologic Logging Part Time to Full Time
Fill Placement and Soil Compaction Full Time
Foundations Foundation Excavation Observations Part Time
Utility Backfill Fill Placement and Soil Compaction Part Time to Full Time
Retaining Wall Backfill Fill Placement and Soil Compaction Part Time to Full Time
Subgrade for Sidewalks,
Curb/Gutter and Pavement Soil Compaction Part Time
Pavement Construction
Base Placement and Compaction Part Time
Asphalt Concrete Placement and
Compaction Full Time
Geocon Project No. G1006-52-05 September 30, 2022
Revised May 5, 2023
LIMITATIONS AND UNIFORMITY OF CONDITIONS
1. The firm that performed the geotechnical investigation for the project should be retained to
provide testing and observation services during construction to provide continuity of
geotechnical interpretation and to check that the recommendations presented for geotechnical
aspects of site development are incorporated during site grading, construction of improvements,
and excavation of foundations. If another geotechnical firm is selected to perform the testing
and observation services during construction operations, that firm should prepare a letter
indicating their intent to assume the responsibilities of project geotechnical engineer of record.
A copy of the letter should be provided to the regulatory agency for their records. In addition,
that firm should provide revised recommendations concerning the geotechnical aspects of the
proposed development, or a written acknowledgement of their concurrence with the
recommendations presented in our report. They should also perform additional analyses deemed
necessary to assume the role of Geotechnical Engineer of Record.
2. The recommendations of this report pertain only to the site investigated and are based upon the
assumption that the soil conditions do not deviate from those disclosed in the investigation. If
any variations or undesirable conditions are encountered during construction, or if the proposed
construction will differ from that anticipated herein, Geocon Incorporated should be notified so
that supplemental recommendations can be given. The evaluation or identification of the
potential presence of hazardous or corrosive materials was not part of the scope of services
provided by Geocon Incorporated.
3. This report is issued with the understanding that it is the responsibility of the owner or his
representative to ensure that the information and recommendations contained herein are brought
to the attention of the architect and engineer for the project and incorporated into the plans, and
the necessary steps are taken to see that the contractor and subcontractors carry out such
recommendations in the field.
4. The findings of this report are valid as of the present date. However, changes in the conditions
of a property can occur with the passage of time, whether they be due to natural processes or
the works of man on this or adjacent properties. In addition, changes in applicable or appropriate
standards may occur, whether they result from legislation or the broadening of knowledge.
Accordingly, the findings of this report may be invalidated wholly or partially by changes
outside our control. Therefore, this report is subject to review and should not be relied upon
after a period of three years.
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6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:32AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 Geo Map.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC 1AP
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
1 6 1
INDEX MAP
NO SCALE
1
FIGURE
2
FIGURE
3
FIGURE
5
FIGURE
4
FIGURE
6
FIGURE
(3')
H H'
........COMPACTED FILL
........UNDOCUMENTED FILL
........PREVIOUSLY PLACED FILL
........ALLUVIUM
....TERRACE DEPOSITS (Dotted Where Buried)
........OTAY FORMATION (Dotted Where Buried)
........OTAY FORMATION (Gritstone) (Dotted Where Buried)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Dotted Where Buried, Queried Where Uncertain)
........APPROX. LOCATION OF EXPLORATORY BORING
........APPROX. LOCATION OF EXPLORATORY TRENCH
........APPROX. DEPTH TO FORMATIONAL (In Feet)
........APPROX. LOCATION OF GEOLOGIC CROSS SECTIONS
........REQUIRED WIDTH OF BUTTRESS (In Feet)
........APPROX. LOCATION OF EXISTING 8-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF EXISTING 6-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF PROPOSED 8-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF PROPOSED 6-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF EXISTING 8-INCH SUBDRAIN
(Geotechnics, 2005)
........APPROX. ELEVATION OF SUBDRAIN (In Feet, MSL)
........APPROX. LOCATION OF OBSERVED BENTONITE CLAYSTONE BED
(Queried Where Uncertain)
........APPROX. ELEVATION OF OBSERVED BENTONITE CLAYSTONE BED
(In Feet, MSL)
........APPROX. ELEVATION OF BASE OF FILL (In Feet, MSL)
GEOCON LEGEND
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363
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380
397
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SECONDARY
DISPOSAL
SITEEnvironmental
Stockpile
342
Qudf
Qudf
To
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To
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To
To
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To
To
Environmental
Stockpile
Qudf
Environmental
Stockpile
Qudf To
Qal/
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Qcf/
Qcf/
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358
354
FALSE
SOIL
ROCK
SLOPE
FALSE
SOIL
ROCK
SLOPE
443
426
438
428421
420
414
408
403
411
416
400
391
397
380
381
378
380
376
373
368
368
400
400
402
408
412
419
424
428
431
420
405
404
408
417
365
370
375
379
382
383
393
404
416
390
398
407
413
482
529
482
439
439
439
QalQal
W=15'
B-2
B-6
B-8
B-9
B-7
B-14
B-19
B-18
B-15
439
423
To
To
387
382
379
374
372
367
357
349
345
343
354
410
419
396
382
373
343
344
348
377
385
386
392
387
413
404
395
404
420
386
366 367
364
367
370
373 372 371
407
375
376
373
376
379
413
424
379
384
392
429 411
386
408
432
421 395
398
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436
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366
367
428
384
374
?
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TEMPORARY STUB FOR
FUTURE CONNECTION
OF SUBDRAINS
TEMPORARY STUB FOR
FUTURE CONNECTION
T-5
T-2
T-3
T-4
T-15
T-9
T-14
T-16
T-17
T-34
T-40
T-35
T-36
T-1
T-18
T-19
T-20
T-21
(2')
(2')
(2')
(2')
(2')
(6')
(7')
(4')
(5')
(4.5')
(3.5')
(5')
(5')
(4')
(6')
(5')
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439
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:34AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 Geo Map.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC 1AP
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
2 6 2
INDEX MAP
NO SCALE
1
FIGURE
2
FIGURE
3
FIGURE
5
FIGURE
4
FIGURE
6
FIGURE
(3')
H H'
........COMPACTED FILL
........UNDOCUMENTED FILL
........PREVIOUSLY PLACED FILL
........ALLUVIUM
....TERRACE DEPOSITS (Dotted Where Buried)
........OTAY FORMATION (Dotted Where Buried)
........OTAY FORMATION (Gritstone) (Dotted Where Buried)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Dotted Where Buried, Queried Where Uncertain)
........APPROX. LOCATION OF EXPLORATORY BORING
........APPROX. LOCATION OF EXPLORATORY TRENCH
........APPROX. DEPTH TO FORMATIONAL (In Feet)
........APPROX. LOCATION OF GEOLOGIC CROSS SECTIONS
........REQUIRED WIDTH OF BUTTRESS (In Feet)
........APPROX. LOCATION OF EXISTING 8-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF EXISTING 6-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF PROPOSED 8-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF PROPOSED 6-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF EXISTING 8-INCH SUBDRAIN
(Geotechnics, 2005)
........APPROX. ELEVATION OF SUBDRAIN (In Feet, MSL)
........APPROX. LOCATION OF OBSERVED BENTONITE CLAYSTONE BED
(Queried Where Uncertain)
........APPROX. ELEVATION OF OBSERVED BENTONITE CLAYSTONE BED
(In Feet, MSL)
........APPROX. ELEVATION OF BASE OF FILL (In Feet, MSL)
GEOCON LEGEND
Qal
To
?
?
Qudf
Qcf
350
B-19
T-57
423
344
W=30'
Tog
Qpf
Qt
OS-1
R-7 R-8
OS-4
LOT B
R-10R-9
DE
L
G
A
D
O
D
R
I
9
E
MHMH
MH MH
N.A.P.
CPF-2
OS-11
OS-13
OS-6
(UNDERLYING
DESIGNATION)
·········
·
·
·
·
·
·····
·
·
·
·
D'
····
·
·
Qa
l
Qal
Qal
Qudf/
Qt
Tog
To
Qt
Qt
Qal/
Qt Qt
Qt
Qt
Qt
Qt
Qt
Qt
Qal/
Qal/To
Qal
Qal
Qal
Qal
Qal
Qal
Qal
Qal
Qal
B-11
B-12
B-10
Qal/
To
To
344
OF SUBDRAINS
EXTEND DRAINS OFF-SITE
TO ALLOW DRAINAGE WITH
HEADWALL OUTLET
T-25
T-20
T-21
T-22
T-27
T-28
T-26
T-39
T-24
T-32
T-23
T-48
T-47
T-46
T-45
T-43
T-44T-42
T-49
T-57
T-56
T-55
(2')
(2')
(3.5')
(1')
(3')
(2')
(5.5')
(3')
(3')
(3')
(3')
(6.5')
(5.5')
(3')
(1.5')
(1.5')
(1')
(2')
(1')
(2')
(1.5')
(1.5)
(2')
(3')
(3')
Tog
Tog
Tog
Tog
To
To
Tog
Tog
NAP
NAP
Qpf
············
·
·
····
····
·
·
·
Qt
Qpf
Qpf
T-41
(2')
·····
·
·
g
TogQal
PROJECT
LIMITS
PROJECT
LIMITS
423
EXTEND DRAINS OFF-SITE
TO ALLOW DRAINAGE WITH
HEADWALL OUTLET
EXTEND DRAINS OFF-SITE
TO ALLOW DRAINAGE WITH
HEADWALL OUTLET
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:36AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 Geo Map.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC 1AP
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
3 6 3
INDEX MAP
NO SCALE
1
FIGURE
2
FIGURE
3
FIGURE
5
FIGURE
4
FIGURE
6
FIGURE
(3')
H H'
........COMPACTED FILL
........UNDOCUMENTED FILL
........PREVIOUSLY PLACED FILL
........ALLUVIUM
....TERRACE DEPOSITS (Dotted Where Buried)
........OTAY FORMATION (Dotted Where Buried)
........OTAY FORMATION (Gritstone) (Dotted Where Buried)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Dotted Where Buried, Queried Where Uncertain)
........APPROX. LOCATION OF EXPLORATORY BORING
........APPROX. LOCATION OF EXPLORATORY TRENCH
........APPROX. DEPTH TO FORMATIONAL (In Feet)
........APPROX. LOCATION OF GEOLOGIC CROSS SECTIONS
........REQUIRED WIDTH OF BUTTRESS (In Feet)
........APPROX. LOCATION OF EXISTING 8-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF EXISTING 6-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF PROPOSED 8-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF PROPOSED 6-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF EXISTING 8-INCH SUBDRAIN
(Geotechnics, 2005)
........APPROX. ELEVATION OF SUBDRAIN (In Feet, MSL)
........APPROX. LOCATION OF OBSERVED BENTONITE CLAYSTONE BED
(Queried Where Uncertain)
........APPROX. ELEVATION OF OBSERVED BENTONITE CLAYSTONE BED
(In Feet, MSL)
........APPROX. ELEVATION OF BASE OF FILL (In Feet, MSL)
GEOCON LEGEND
Qal
To
?
?
Qudf
Qcf
350
B-19
T-57
423
344
W=30'
Tog
Qpf
Qt
OS-1
P-2A
COMMUNITY PARK
OS-2
OS-5
OS-13
P-2A
COMMUNITY PARK
P-2B
COMMUNITY PARK
Qal/
Qt
Qt
Qt
Qt
Qt
Qt
Qal/
Qal/
Qt
T-29
T-33
T-42
T-50
(10')
(3')
(1.5')
(4')
Qpf
Qpf
Qt
Qpf
Qpf
PROJECT
LIMITS
PROJECT
LIMITS
PROJECT
LIMITS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:42AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 Geo Map.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC 1AP
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
4 6 4
INDEX MAP
NO SCALE
1
FIGURE
2
FIGURE
3
FIGURE
5
FIGURE
4
FIGURE
6
FIGURE
(3')
H H'
........COMPACTED FILL
........UNDOCUMENTED FILL
........PREVIOUSLY PLACED FILL
........ALLUVIUM
....TERRACE DEPOSITS (Dotted Where Buried)
........OTAY FORMATION (Dotted Where Buried)
........OTAY FORMATION (Gritstone) (Dotted Where Buried)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Dotted Where Buried, Queried Where Uncertain)
........APPROX. LOCATION OF EXPLORATORY BORING
........APPROX. LOCATION OF EXPLORATORY TRENCH
........APPROX. DEPTH TO FORMATIONAL (In Feet)
........APPROX. LOCATION OF GEOLOGIC CROSS SECTIONS
........REQUIRED WIDTH OF BUTTRESS (In Feet)
........APPROX. LOCATION OF EXISTING 8-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF EXISTING 6-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF PROPOSED 8-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF PROPOSED 6-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF EXISTING 8-INCH SUBDRAIN
(Geotechnics, 2005)
........APPROX. ELEVATION OF SUBDRAIN (In Feet, MSL)
........APPROX. LOCATION OF OBSERVED BENTONITE CLAYSTONE BED
(Queried Where Uncertain)
........APPROX. ELEVATION OF OBSERVED BENTONITE CLAYSTONE BED
(In Feet, MSL)
........APPROX. ELEVATION OF BASE OF FILL (In Feet, MSL)
GEOCON LEGEND
Qal
To
?
?
Qudf
Qcf
350
B-19
T-57
423
344
W=30'
Tog
Qpf
Qt
OS-3
OS-6
(UNDERLYING
DESIGNATION)
Qal/
Qal/
Qt Qt
QalQal/
WILEY ROAD
Qal/
Qal/
Qal/
T-32
T-31
T-54
T-55(3')
(3')
(3.5')
(3')
NAP
PROJECT
LIMITS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:44AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 Geo Map.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC 1AP
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
5 6 5
INDEX MAP
NO SCALE
1
FIGURE
2
FIGURE
3
FIGURE
5
FIGURE
4
FIGURE
6
FIGURE
(3')
H H'
........COMPACTED FILL
........UNDOCUMENTED FILL
........PREVIOUSLY PLACED FILL
........ALLUVIUM
....TERRACE DEPOSITS (Dotted Where Buried)
........OTAY FORMATION (Dotted Where Buried)
........OTAY FORMATION (Gritstone) (Dotted Where Buried)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Dotted Where Buried, Queried Where Uncertain)
........APPROX. LOCATION OF EXPLORATORY BORING
........APPROX. LOCATION OF EXPLORATORY TRENCH
........APPROX. DEPTH TO FORMATIONAL (In Feet)
........APPROX. LOCATION OF GEOLOGIC CROSS SECTIONS
........REQUIRED WIDTH OF BUTTRESS (In Feet)
........APPROX. LOCATION OF EXISTING 8-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF EXISTING 6-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF PROPOSED 8-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF PROPOSED 6-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF EXISTING 8-INCH SUBDRAIN
(Geotechnics, 2005)
........APPROX. ELEVATION OF SUBDRAIN (In Feet, MSL)
........APPROX. LOCATION OF OBSERVED BENTONITE CLAYSTONE BED
(Queried Where Uncertain)
........APPROX. ELEVATION OF OBSERVED BENTONITE CLAYSTONE BED
(In Feet, MSL)
........APPROX. ELEVATION OF BASE OF FILL (In Feet, MSL)
GEOCON LEGEND
Qal
To
?
?
Qudf
Qcf
350
B-19
T-57
423
344
W=30'
Tog
Qpf
Qt
P-2A
COMMUNITY PARK
OS-2
OS-2
OS-5 P-2A
COMMUNITY PARK
P-2B
COMMUNITY PARK
Qt
Qal/
Qal/
WILEY
R
O
A
D
Qal/
Qal/
T-30
T-33
T-53T-52
T-51
T-50
(11')
(3')
(4')
(3')
(5')(2.5')
PROJECT
LIMITS
PROJECT
LIMITS
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:47AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 Geo Map.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC 1AP
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
6 6 6
INDEX MAP
NO SCALE
1
FIGURE
2
FIGURE
3
FIGURE
5
FIGURE
4
FIGURE
6
FIGURE
(3')
H H'
........COMPACTED FILL
........UNDOCUMENTED FILL
........PREVIOUSLY PLACED FILL
........ALLUVIUM
....TERRACE DEPOSITS (Dotted Where Buried)
........OTAY FORMATION (Dotted Where Buried)
........OTAY FORMATION (Gritstone) (Dotted Where Buried)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Dotted Where Buried, Queried Where Uncertain)
........APPROX. LOCATION OF EXPLORATORY BORING
........APPROX. LOCATION OF EXPLORATORY TRENCH
........APPROX. DEPTH TO FORMATIONAL (In Feet)
........APPROX. LOCATION OF GEOLOGIC CROSS SECTIONS
........REQUIRED WIDTH OF BUTTRESS (In Feet)
........APPROX. LOCATION OF EXISTING 8-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF EXISTING 6-INCH SOIL-ROCK FILL SUBDRAIN
........APPROX. LOCATION OF PROPOSED 8-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF PROPOSED 6-INCH CANYON SUBDRAIN
........APPROX. LOCATION OF EXISTING 8-INCH SUBDRAIN
(Geotechnics, 2005)
........APPROX. ELEVATION OF SUBDRAIN (In Feet, MSL)
........APPROX. LOCATION OF OBSERVED BENTONITE CLAYSTONE BED
(Queried Where Uncertain)
........APPROX. ELEVATION OF OBSERVED BENTONITE CLAYSTONE BED
(In Feet, MSL)
........APPROX. ELEVATION OF BASE OF FILL (In Feet, MSL)
GEOCON LEGEND
Qal
To
?
?
Qudf
Qcf
350
B-19
T-57
423
344
W=30'
Tog
Qpf
Qt
0 200100 300 400 500 600 700 800 900 120010001100 1300 1400 1500 1600 185017001800
0 200100 300 400 500 600 700 800 900 120010001100 1300 1350
0 200100 300 400 500 600 700 800 900 120010001100 1300 1400 1450
D I S T A N C E
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION A-A'
D I S T A N C E
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION B-B'
D I S T A N C E
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION C-C'
250
350
450
550
650
A
E
L
E
V
A
T
I
O
N
(
M
S
L
)
250
350
450
550
650
B
E
L
E
V
A
T
I
O
N
(
M
S
L
)
E
L
E
V
A
T
I
O
N
(
M
S
L
)
250
350
450
550
650
E
L
E
V
A
T
I
O
N
(
M
S
L
)
250
350
450
550
650
A'
B'
250
350
450
550
650
C
E
L
E
V
A
T
I
O
N
(
M
S
L
)
C'
E
L
E
V
A
T
I
O
N
(
M
S
L
)
250
350
450
550
650
B-1
(Projected
75' East)B-3
(Projected
50' West)
B-2
PROPOSED
GRADE
Tob BENTONITE
CLAYSTONE BED
EXISTING
GRADE
To
To
To
N14°W
B-13
(Projected
20' West)
??????
N33°W
B-4
(Projected
120' East)
B-5
(Projected
310' East)
B-6
(Projected
10' West)
To
To
To
PROPOSED
MAIN ST
EXISTING
GRADE PROPOSED
GRADE
?????????
N21°W
B-2
(Projected
30' East)
T-34
(Projected
100' East)
T-40
(Projected
200' West)
PROPOSED
GRADE
EXISTING
GRADE
To To ToTob BENTONITE
CLAYSTONE BED
??????
Tog Tog
Tog
Tog TogTog
Tog Tog Tog
?
PROPOSED UNDERCUT
FOR BENTONITE
PROPOSED UNDERCUT
FOR BENTONITE
PROPOSED MSE
RETAINING WALL
25' WIDE FILL AREA
BEHIND MSE WALL
To
ENVIRONMENTAL
STOCKPILE
Tob BENTONITE
CLAYSTONE BED
PROPOSED UNDERCUT
FOR BENTONITE
Tob BENTONITE
CLAYSTONE BED
ORIGINAL
GRADE
Tob BENTONITE
CLAYSTONE BED
20' WIDE FILL AREA
BEHIND MSE WALL
ORIGINAL
GRADE
Qudf
Tob BENTONITE
CLAYSTONE BED
Qudf
Qudf
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:48AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 XSection.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC CROSS SEC8ION
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
1 2 7
B-19
........ALLUVIUM
........OTAY FORMATION
........OTAY FORMATION (Gritstone)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Queried Where Uncertain)
.........APPROX. LOCATION OF EXPLORATORY BORING
.........APPROX. LOCATION OF EXPLORATORY TRENCH
GEOCON LEGEND
?
Qal
To
Tog
B-41
0 200100 300 400 500 600 700 800 900 1000 1050
0 200100 300 400 500 600 700 800 900 120010001100 1300 13500200100300400500600700800900
D I S T A N C E
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION D-D'
D I S T A N C E
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION E-E'
D I S T A N C E
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION F-F'
200
300
400
500
600
D
E
L
E
V
A
T
I
O
N
(
M
S
L
)
200
300
400
500
600
E
E
L
E
V
A
T
I
O
N
(
M
S
L
)
D'
E
L
E
V
A
T
I
O
N
(
M
S
L
)
200
300
400
500
600
E'
E
L
E
V
A
T
I
O
N
(
M
S
L
)
200
300
400
500
600
200
300
400
500
600
F
E
L
E
V
A
T
I
O
N
(
M
S
L
)
F'
E
L
E
V
A
T
I
O
N
(
M
S
L
)
200
300
400
500
600
N16°W
B-9 EXISTING
GRADE
Tob BENTONITE
CLAYSTONE BED
ToTo T-41
????
PROPOSED
GRADE
N73°E
PROPOSED
GRADE
EXISTING
GRADE
ToToTo
B-8
(Projected
along contour)
Qal
INTERSECTION
D-D'
B-15B-19
(Projected
60' North)
?????
ORIGINAL
GRADE
EXISTING
GRADE
?????
Tog Tog
Tog TogTog
Tog Tog
To
ToTo
0 200100 300 400 500 600 700
D I S T A N C E
350
450
550
650
E
L
E
V
A
T
I
O
N
(
M
S
L
)
E
L
E
V
A
T
I
O
N
(
M
S
L
)
350
450
550
650
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION G-G'
G G'
0 200100 300 400 500 600
D I S T A N C E
350
450
550
650
E
L
E
V
A
T
I
O
N
(
M
S
L
)
E
L
E
V
A
T
I
O
N
(
M
S
L
)
350
450
550
650
SCALE: 1" = 100' (Vert. = Horiz.)
GEOLOGIC CROSS-SECTION H-H'
H H'
750 750
750 750
PROPOSED
20' BUTTRESS Tob BENTONITE
CLAYSTONE BED
PROPOSED
30' BUTTRESS
PROPOSED
BUTTRESS
Tob BENTONITE
CLAYSTONE BED
B-1
(Projected
10' North)
SR-125
Tob BENTONITE
CLAYSTONE BED
To
To
To
PROPOSED
GRADE
EXISTING
GRADE
SR-125PROPOSED MSE
RETAINING WALL
To To
PROPOSED
GRADE
EXISTING
GRADE
Tob BENTONITE
CLAYSTONE BED
Tob BENTONITE
CLAYSTONE BED
To
B-7
(Projected
20' North
PROPOSED MSE
RETAINING WALL
Tob BENTONITE
CLAYSTONE BED
PROPOSED
CMU WALL
ORIGINAL
GRADE
Qcf
Qudf
PROPOSED
GRADE
Tob BENTONITE
CLAYSTONE BED
PROPOSED
20' BUTTRESS20' WIDE FILL AREA
BEHIND WALL
1:1 BACKCUT
N75°E N70°E
N65°E
To
6960 FLANDERS DRIVE - SAN DIEGO, CALIFORNIA 92121 - 2974
PHONE 858 558-6900 - FAX 858 558-6159 SHEET OF
PROJECT NO.
SCALE DATE
FIGURE
Plotted:05/05/2023 6:49AM | By:ALVIN LADRILLONO | File Location:W:\1_GEOTECH\G1000\G1006-52-05\2023-05-05\G1006-52-05 XSection.20.dwg
GEOTECHNICAL ENVIRONMENTAL MATERIALS
1" =
GEOLOGIC CROSS SEC8ION
OTAY RANCH - VILLAGE 8 EAST
CHULA VISTA, CALIFORNIA
100'05 - 05 - 2023
G1006 - 52 - 05
2 2 8
B-19
........ALLUVIUM
........OTAY FORMATION
........OTAY FORMATION (Gritstone)
........APPROX. LOCATION OF GEOLOGIC CONTACT
(Queried Where Uncertain)
.........APPROX. LOCATION OF EXPLORATORY BORING
.........APPROX. LOCATION OF EXPLORATORY TRENCH
GEOCON LEGEND
?
Qal
To
Tog
B-41
APPENDIX A
APPENDIX A
PREVIOUS BORING AND TRENCH LOGS
FOR
OTAY RANCH VILLAGE 8 WEST
CHULA VISTA, CALIFORNIA
PROJECT NO. G1006-52-05
TOPSOIL
Medium dense, moist, brown, Sandy CLAY; trace rootlets
OTAY FORMATION (To)
Hard, moist, gray, Sandy SILTSTONE; blocky texture; some carbonates
Very dense, damp, gray, Silty, fine-grained SANDSTONE; moderately
cemented
Hard to dense, damp, olive brown, Sandy CLAYSTONE; interlayered with
dense, Silty SANDSTONE
-Becomes increasingly fine-grained at 19 feet
Very dense, damp, grayish brown, Silty, fine-grained SANDSTONE,
moderately cemented
-Subtle gradational change to claystone
115.8
110.1
13.3
13.6
B1-1
B1-2
B1-3
5
5
SC
ML
SM
CL/SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-1,
Log of Boring B 1, Page 1 of 3
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 1
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)571'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very hard, brown, Sandy CLAYSTONE, about 3" thick N20ºW, 3ºSE
Very hard, damp, olive brown to gray, Sandy SILTSTONE; interlayered with
fissile laminations of brown, Sandy CLAYSTONE
-Gradational contact
Very hard, damp, pinkish to grayish brown, bentonitic CLAYSTONE;
N25ºW, 5ºSE; approximate 8" thick fractured and well developed
Dense, dry, light gray to whitish, Silty, fine-grained SANDSTONE
Very hard, damp, grayish brown, bentonite CLAYSTONE
Dense, dry, light gray to whitish, Silty, fine-grained SANDSTONE
-Massive homogeneous, moderately cemented, undisturbed and intact
-Trace angular gravels
Very dense, damp, gray-brown, Silty SANDSTONE
-Becomes interlayered, fine SANDSTONE to Sandy SILTSTONE
102.5
93.1
111.1
23.0
31.5
13.9
B1-4
B1-9
B1-5
B1-6
B1-7
10
6
10
CL
CH
SM
CH
SM
SM
SM/ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
Figure A-1,
Log of Boring B 1, Page 2 of 3
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 1
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)571'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very hard, damp, olive brown, Sandy CLAYSTONE to Sandy SILTSTONE
BORING TERMINATED AT 64 FEET
No groundwater encountered
89.1 34.2B1-8 12CL-ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
60
62
64
Figure A-1,
Log of Boring B 1, Page 3 of 3
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 1
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)571'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, dark brown, Clayey SAND; some carbonates
OTAY FORMATION (To)
Medium dense, damp, light gray, Silty, fine to medium SANDSTONE; blocky
texture; occasional angular clasts of well cemented sandstone; trace
carbonates
-Becomes dense at five feet
Very dense, damp, light gray, Silty, fine-grained SANDSTONE; moderately
cemented
-Subtle gradational color change to reddish brown
-Trace clay
-Trace gravels to 20 feet
-Sharp, near horizontal contact, N25ºW, 5ºSE
Very dense, damp, light reddish brown to brown, Silty, fine-to medium
grained SANDSTONE
-Becomes very difficult excavation
Very dense, damp, dark gray, Silty, fine-grained SANDSTONE; well
cemented
-At 29 feet, 1" thick, trace clasts of bentonitic CLAYSTONE; non contiguous
103.1
110.9
22.2
16.4
B2-1
B2-2
B2-3
5
7
SC
SM
SM
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-2,
Log of Boring B 2, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 2
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)515'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very dense, dry, gray brown to whitish, Silty, fine-grained SANDSTONE;
slightly cemented; trace biotite micas
-Becomes light reddish brown
Very hard, dry, light brown, Sandy SILTSTONE
-Massive homogeneous
BORING TERMINATED AT 45 FEET
No groundwater encountered
108.9
105.1
16.9
7.4
B2-4
B2-5
10
10/7"
SM
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
36
38
40
42
44
Figure A-2,
Log of Boring B 2, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 2
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)515'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey SAND
OTAY FORMATION (To)
Dense, damp, light gray, Silty, fine -grained; some carbonates
-Clay lense about 3" thick
Hard, damp, gray, Sandy SILTSTONE
Very dense,damp, whitish to gray, Silty, fine-grained SANDSTONE; with
interlayered Sandy SILTSTONE
-Subtle gradational contact
Hard, damp, gray, Sandy SILTSTONE
-Becomes dark gray siltstone
-Faint bedding
Very hard, damp, olive brown to brown, Sandy to Clayey SILTSTONE with
noncontinuous clasts of CLAYSTONE
N70ºW, 5ºSE
115.9
104.1
115.5
8.6
19.9
12.0
B3-1
B3-2
B3-3
B3-4
B3-5
5
6
8
1
SC
SM
ML
SM
ML
ML
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-3,
Log of Boring B 3, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 3
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)558'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very dense, damp, brown, Silty, fine SANDSTONE
Very hard, damp, light grayish brown, bentonitic CLAYSTONE; waxy texture
bed approximately 3" thick
-Near horizontal contact
Very hard, damp, olive brown, Sandy SILTSTONE
-Massive, homogeneous, intact
Very hard, dry, light gray, Sandy SILTSTONE
BORING TERMINATED AT 44 FEET
No groundwater encountered
117.9 15.8
B3-6
B3-7 10/8"
CH
ML
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
36
38
40
42
44
Figure A-3,
Log of Boring B 3, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 3
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)558'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, dark brown, Clayey SAND
OTAY FORMATION (To)
Dense, moist, gray brown, Silty, fine-grained SANDSTONE; blocky texture
with trace carbonates
Dense, dry, gray, Silty, fine-grained SANDSTONE; micaceous
Very hard, olive, bentonitic CLAYSTONE, 6-inches thick, highly weathered
Very dense, damp, light grayish brown, Silty, fine-grained SANDSTONE;
moderately to locally strongly cemented
Hard, damp, brown, Sandy CLAYSTONE; 1' thick
Very hard, damp, dark gray, Sandy SILTSTONE
111.4 17.9B4-1
B4-2
5
8/10"
SC
SM
SM
CH
SM
CL
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-4,
Log of Boring B 4, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 4
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)588'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
-Very difficult drilling, auger attached to past 30 feet, sampling not practical
-Massive and intact
Very hard, olive gray, Silty CLAYSTONE to Clayey SILTSTONE; trace
clasts of reworked claystone embedded with matrix
BORING TERMINATED AT 44 FEET
No groundwater encountered
105.3 24.1
B4-3
B4-4
ML
CL-ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
36
38
40
42
44
Figure A-4,
Log of Boring B 4, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 4
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)588'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp, brown, Clayey SAND; some rootlets
OTAY FORMATION (To)
Dense, damp, light gray, Silty, fine SANDSTONE, some carbonates
Dense, damp, light gray, Silty, fine SANDSTONE; moderately cemented
-Gradational contact
Very hard, olive brown, Silty CLAYSTONE; trace clasts of reworked
bentonitic claystone within matrix
-Gradational contact
Very dense, damp, light gray, Silty, fine-grained SANDSTONE; trace clasts
of reworked bentonitic claystone within matrix
Very dense, damp, light grayish brown, Silty, fine-grained SANDSTONE
108.2
114.6
17.4
12.5
B5-1
B5-2
B5-3
5
7/10"
SC
SM
SM
CL/CH
SM/CH
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-5,
Log of Boring B 5, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 5
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)553'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very hard, light olive gray, Sandy SILTSTONE
-Becomes interlayered with very dense, Silty, fine-grained SANDSTONE;
faintly bedded
-Becomes interlayered, very dense, Silty, fine-grained SANDSTONE to very
hard, Sandy SILTSTONE; faintly bedded
Very hard, damp, gray, Sandy SILTSTONE
BORING TERMINATED AT 45 FEET
No groundwater encountered
100.3
116.0
21.3
10.3
B5-4
B5-5
7
10/8"
ML
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
36
38
40
42
44
Figure A-5,
Log of Boring B 5, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 5
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)553'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, brown, Silty SAND
OTAY FORMATION (To)
Medium dense, moist, light gray, Silty, fine-grained SANDSTONE; blocky
texture, trace carbonate
-Well cemented, sandstone layer 4-inch thick
Hard, damp, dark gray, Sandy SILTSTONE
-Becomes interbedded, Sandy SILTSTONE and Silty SANDSTONE
Very hard, damp, olive brown, Sandy CLAYSTONE; approximately 8" thick
Very hard to dense, gray to reddish gray brown, interbedded, Sandy
SILTSTONE to Silty fine-grained SANDSTONE
-Massive and intact
-Homogeneous to about 30 feet
114.3
114.3
15.6
18.6
B6-2
B6-2
4
6
SM
SM
ML
CL
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-6,
Log of Boring B 6, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 6
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)519'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very dense, damp, light gray to yellowish brown, fine-to-medium grained
SANDSTONE
BORING TERMINATED AT 32 FEET
No groundwater encountered
116.2 13.5B6-3 10/8"SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
Figure A-6,
Log of Boring B 6, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 6
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)519'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Silty SAND
OTAY FORMATION (To)
Medium dense, moist, gray, Silty, fine-grained SANDSTONE; some
carbonates, blocky texture
Very hard, damp, light grayish brown, Sandy SILTSTONE
-Grades to Clayey SILTSTONE/Sandy CLAYSTONE from 19-20 feet
Very dense, damp, gray, Silty, fine-grained SANDSTONE
-Clasts of well cemented sandstone
-Concretion layer about 3-inch thick
105.2
110.8
8.7
12.6
B7-1
B7-2
B7-3
8/10"
6/10"
SM
SP
ML
ML/CL
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-7,
Log of Boring B 7, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 7
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)479'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very dense, damp, gray to reddish brown, Silty, fine-grained SANDSTONE
BORING TERMINATED AT 35 FEET
No groundwater encountered
115.9 13.4B7-4 6/3"SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
Figure A-7,
Log of Boring B 7, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 7
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)479'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, brown, Clayey SAND
OTAY FORMATION (To)
Dense, moist, gray, Silty, fine to medium SANDSTONE
-Near horizontal contact
OTAY FORMATION (Tog)
Very dense, damp, yellowish to gray brown, Silty, fine-to coarse
SANDSTONE ("GRITSTONE"); generally well-graded and intact
-Massive and homogeneous, some fine gravel, sized clasts, intact
-Very difficult excavation
-Sampling not practical
BORING TERMINATED AT 20 FEET
No groundwater encountered
123.3 8.1B8-1 8/10"
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
Figure A-8,
Log of Boring B 8, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 8
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)379'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey SAND
OTAY FORMATION (To)
Medium dense to dense, moist, gray, Silty SANDSTONE
Hard, dense, brown, Sandy CLAYSTONE
Very hard, olive brown, Sandy SILTSTONE; trace clasts of claystone within
matrix
Very dense, damp, gray, Silty SANDSTONE
Hard, moist, olive brown, Silty CLAYSTONE; N75ºE, 5ºSW
Hard, damp, olive gray to pink and white, bentonitic CLAYSTONE; fractured
and approximately 12" thick; well developed
-Distinct and continuous bed of bentonite
Very dense, damp, reddish brown to brown, Silty, fine-grained SANDSTONE
Very dense, dry, whitish gray, Silty, medium to coarse-grained
SANDSTONE; some fine gravels and cobbles, massive and intact
-Large auger attached
-Very difficult excavation, practical refusal
100.4
116.3
24.3
14.6
B9-1
B9-2
6/10"
6/10"
SC
SM
CL
ML
SM
CL
CH
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-9,
Log of Boring B 9, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 9
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)440'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
BORING TERMINATED AT 30 FEET
No groundwater encountered
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
Figure A-9,
Log of Boring B 9, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 9
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)440'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, dark brown, Clayey SAND
OTAY FORMATION (To)
Very dense, reddish brown, Silty, fine-to coarse SAND; some gravels
-Sharp horizontal contact
OTAY FORMATION (Tog)
Very dense, damp, grayish brown, Silty, medium-to coarse-grained
SANDSTONE; ("GRITSTONE"); massive and intact
-Trace subangular gravels, up to 2 -inches in maximum dimension
-Massive, very dense, difficult excavation, practical refusal
-Trace pockets of gravel, 2"-4" within matrix
-Very difficult drilling, sampling not practical
137.7 5.2
B10-1
B10-2
8/8"
8/8"
SC
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-10,
Log of Boring B 10, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 10
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)379'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
BORING TERMINATED AT 30 FEET
No groundwater encountered
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
Figure A-10,
Log of Boring B 10, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 10
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)379'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Silty SAND
OTAY FORMATION (Tog)
Dense, moist, gray to yellowish brown, Silty, fine-to-coarse SANDSTONE ("
GRITSTONE")
-Clasts of subangular gravel and cobble up to 4-inches in matrix dimension
Very dense, dry, whitish gray, Silty, medium-to-coarse grained
SANDSTONE; moderately cemented
-Becomes well cemented, difficult excavation
-Increased conglomerate (gravel, cobble) clasts metavolcanic rock
-Massive, homogeneous
BORING TERMINATED AT 25 FEET
No groundwater encountered
110.4 4.6B11-1
SM
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
Figure A-11,
Log of Boring B 11, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 11
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)354'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Stiff, moist, dark brown, Sandy CLAY, trace organic
-Rootlets and abundant carbonates at about 3.5 feet
OTAY FORMATION (Tog)
Very dense, dry, yellowish brown, Silty, medium-to-coarse SANDSTONE;
("GRITSTONE"), moderately cemented
-Gravel and cobble up to 2"-4", massive and intact
-Very difficult excavation, practical refusal with auger attached
BORING TERMINATED AT 16 FEET
No groundwater encountered
133.7 7.3
B12-1
B12-2 8/8"
CL
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
Figure A-12,
Log of Boring B 12, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 12
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)370'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, dry, brown, Clayey, fine to medium SAND
OTAY FORMATION (To)
Medium dense to dense, light gray, Silty, fine- to medium-grained
SANDSTONE
-Becomes dense; slightly cemented
Very dense, damp, light gray, Silty, fine- to medium-grained SANDSTONE;
moderately cemented
-Thinly bedded
Hard, damp, olive brown, Sandy CLAYSTONE
Very dense, damp, gray, Silty, fine-grained SANDSTONE; medium cemented
Very dense, damp, light gray, Silty, fine-grained SANDSTONE
Hard, moist, brown, Silty, bentonitic CLAYSTONE approximately 1 foot
thick; poorly developed
Very dense, damp, grayish brown, Silty, fine- to medium-grained
SANDSTONE;
114.1
90.9
13.5
28.2
B13-1
B13-2
8
5
SC
SM
SM
CL
SM
SM
CH
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-13,
Log of Boring B 13, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 13
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-04-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)560'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
-Becomes light gray to whitish with trace rip-up clast of whitish bentonite
CLAYSTONE within SANDSTONE matrix
Hard,damp, pinkish to grayish brown, bentonitic CLAYSTONE; N25º,5ºSE;
approx. 12-inch thick; fractural and well developed
Very dense, damp, brown, Silty, fine-grained SANDSTONE; moderately
cemented
Very dense, damp, light brown, Silty, fine-grained SANDSTONE
-Auger attached
-Very dense, difficult drilling
-Massive
BORING TERMINATED AT 51 FEET
No groundwater encountered
66.1
114.4
119.2
49.5
14.6
11.6
B13-3
B13-4
B13-5
6
10/10"
10/10"
CH
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
36
38
40
42
44
46
48
50
Figure A-13,
Log of Boring B 13, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 13
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-04-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)560'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey, fine to medium SAND
OTAY FORMATION (To)
Medium dense, moist, light grayish brown, Silty, fine-grained SANDSTONE;
trace clay
Dense, damp, light gray, Silty, fine-grained SANDSTONE; slightly cemented;
trace clay and manganese oxide staining
-Thinly bedded
-Very difficult excavation
Very dense, moist, grayish brown, Silty, fine-grained SANDSTONE;
moderately cemented; trace gravel
Very dense, damp, grayish brown, medium- to coarse-grained SANDSTONE
BORING TERMINATED AT 28 FEET
No groundwater encountered
111.2
115.6
16.7
14.7
B14-1
B14-2
4
8/10"
SC
SM
SM
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-14,
Log of Boring B 14, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 14
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-04-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)436'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp, brown, Silty, fine to medium SAND
OTAY FORMATION (To)
Medium dense, damp, light gray, Silty, fine- to medium-grained
SANDSTONE; trace carbonates
-Becomes dense; moderately cemented
Hard, moist, olive brown, Sandy CLAYSTONE
Hard, moist, olive brown, Silty CLAYSTONE; grades to bentonite claystone
at 21 feet
Medium stiff, moist, whitish gray, bentonitic CLAYSTONE
Very dense, damp, reddish brown, Silty, fine-grained SANDSTONE
Very dense, damp, gray, Silty, fine- to medium-grained SANDSTONE
BORING TERMINATED AT 28 FEET
No groundwater encountered
SM
SM
CL
CL
CH
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-15,
Log of Boring B 15, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 15
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-05-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)444'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey, fine to medium SAND
OTAY FORMATION (To)
Medium dense, moist, gray, Silty, fine- to medium-grained SANDSTONE;
blocky texture; trace carbonate
-Becomes dense
Dense, damp, light gray, Silty, fine grained SANDSTONE; slightly cemented
Very hard, olive brown, bentonitic CLAYSTONE approx. 1.5 feet thick
Very dense, light grayish brown, Silty, fine grained SANDSTONE;
moderately cemented
-Becomes well cemented
Very hard, damp, gray, Sandy SILTSTONE
119.0
111.3
116.3
10.3
14.0
15.1
B16-1
B16-2
B16-3
7
5
10
SC
SM
SM
CH
SM
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-16,
Log of Boring B 16, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 16
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-05-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)586'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
BORING TERMINATED AT 30 FEET
No groundwater encountered
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
Figure A-16,
Log of Boring B 16, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 16
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-05-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)586'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey, fine to medium SAND
OTAY FORMATION (To)
Medium dense, moist, light gray, Silty, fine- to medium-grained
SANDSTONE; blocky texture
Very dense, gray, Silty, fine-grained SANDSTONE
Hard, damp, light olive brown, Sandy CLAYSTONE
Very dense, gray, Silty, fine- to medium-grained SANDSTONE; slightly
cemented
Very dense, damp, light gray, Silty, fine- to medium-grained SANDSTONE;
moderately cemented
-Homogeneous
Very dense, damp, grayish brown, Silty, fine to medium SANDSTONE; well
cemented
99.8
115.2
23.5
13.3
B17-1
B17-2
5
10
SC
SM
SM
CL
SM
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Figure A-17,
Log of Boring B 17, Page 1 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 17
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-05-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)604'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
Very hard, damp, olive gray, bentonitic CLAYSTONE; poorly developed
Very dense, damp, grayish brown, Silty, fine to medium SANDSTONE; well
cemented
BORING TERMINATED AT 40 FEET
No groundwater encountered
122.7 11.5B17-3
CH
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
30
32
34
36
38
40
Figure A-17,
Log of Boring B 17, Page 2 of 2
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 17
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-05-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)604'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey, fine to medium SAND
OTAY FORMATION (To)
Dense, moist, light gray, Silty, fine-grained SANDSTONE
Medium stiff, damp, whitish gray, bentonite CLAYSTONE; highly
weathered; trace rootlets and carbonates; well developed
Very dense, damp, light reddish brown, Silty, fine grained SANDSTONE
Very dense, damp, light grayish brown, Silty, fine- to medium-grained
SANDSTONE
BORING TERMINATED AT 21 FEET
No groundwater encountered
110.6
109.6
8.9
18.6
B18-1
B18-2
6/10"
50/10"
SC
SM
CH
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
Figure A-18,
Log of Boring B 18, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 18
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-05-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)446'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp, Silty, fine to medium SAND; krotovina from 2.5 to 3 feet
OTAY FORMATION (To)
Dense, moist, light gray, Silty, fine- to medium-grained SANDSTONE
-Becomes reddish brown with locally cemented zones
Dense, damp, light grayish brown, Silty, fine- to medium-grained
SANDSTONE; slightly cemented
-Alternating layers of siltstone/sandstone
-Cemented zone; some gravels
Very dense, damp, grayish brown, Silty, fine to grained SANDSTONE
BORING TERMINATED AT 21 FEET
No groundwater encountered
114.0
109.6
16.3
14.5
B19-1
B19-2
8
8
SM
SM
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
20
Figure A-19,
Log of Boring B 19, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
EZ BORE PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
BORING B 19
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.09-05-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)404'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose to medium dense, damp, dark brown, Clayey, fine-to coarse SAND;
some cobbles
Medium dense, damp, light brown to grayish brown, Silty, fine to coarse
SAND; up to ½" gravel
OTAY FORMATION (Tog)
Very dense, damp, light grayish brown, Silty, fine-to coarse-grained
SANDSTONE; ("GRITSTONE") up to ½" gravel
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
T1-1
T1-2
SC
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-20,
Log of Trench T 1, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 1
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)370'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, moist, dark brown, fine Sandy CLAY; rootlets
Loose to medium dense, dry, dark grayish brown, Silty, fine SAND; trace clay
lense
-Trace carbonates
Medium dense, moist, dark brown with lighter nodules of Silty SAND,
Clayey, fine to medium SAND or Sandy CLAY
OTAY FORMATION (To)
Very dense, moist, light brown to white, Clayey, fine-to coarse grained
SANDSTONE; trace gravel up to 3", oxidized
TRENCH TERMINATED AT 8 FEET
No groundwater encountered
CL
SM
SC
SC
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-21,
Log of Trench T 2, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 2
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)370'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, moist, dark brown, fine-to medium Sandy CLAY
OTAY FORMATION (To)
Dense to very dense, damp, light brown, Clayey, fine to coarse-grained
SANDSTONE
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
CL
SC
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-22,
Log of Trench T 3, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 3
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)380'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, damp to moist, dark brown, Silty CLAY
-Few carbonates
OTAY FORMATION (To)
Dense to very dense, damp, light grayish brown, Silty, fine-to coarse-grained
SANDSTONE; few gravel
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
CL
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-23,
Log of Trench T 4, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 4
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)410'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose to medium dense, dry to damp, grayish brown, Silty, fine to medium
SAND; trace clay and rootlets
OTAY FORMATION (To)
Dense to very dense, dry, light brown, fine-grained SANDSTONE; weakly
cemented, massive
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-24,
Log of Trench T 5, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 5
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)444'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose to medium dense, damp, dark brown, Clayey, fine to medium SAND or
fine to medium Sandy CLAY
OTAY FORMATION (To)
Very dense, dry, light brown to white, Silty, fine-grained SANDSTONE,
moderately cemented
TRENCH TERMINATED AT 6 FEET
No groundwater encountered
T6-1
SC-CL
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-25,
Log of Trench T 6, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 6
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)488'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, dark brown, Clayey, fine SAND; rootlets
OTAY FORMATION (To)
Dense, dry, light gray, Silty, fine-grained SANDSTONE; moderately
cemented; blocky structure
Stiff, dry, light brown, Clayey SILTSTONE
TRENCH TERMINATED AT 8 FEET
No groundwater encountered
T7-1
SC
SM
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-26,
Log of Trench T 7, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 7
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)560'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp to moist, dark brown to dark grayish brown, Silty, fine SAND;
some clay; trace rootlets
OTAY FORMATION (To)
Dense to very dense, damp, light brownish gray, Silty, fine-grained
SANDSTONE; very thinly bedded to moderately bedded
-Massive and homogeneous
TRENCH TERMINATED AT 9 FEET
No groundwater encountered
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-27,
Log of Trench T 8, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 8
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-21-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)570'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose to medium dense, damp, dark brown, Clayey, fine SAND; rootlets;
trace carbonates and krotovinas
OTAY FORMATION (To)
Very dense, dry, light grayish brown, Silty, fine-grained SANDSTONE
TRENCH TERMINATED AT 6 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-28,
Log of Trench T 9, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 9
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)444'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp, brown, Silty, fine SAND; rootlets, few carbonates
OTAY FORMATION (To)
Dense to very dense, reddish brown, Silty, fine-grained SANDSTONE
-Thinly to moderately bedded, light grayish brown; blocky texture, trace
carbonates
TRENCH TERMINATED AT 6.5 FEET
No groundwater encountered
T10-1
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-29,
Log of Trench T 10, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 10
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)520'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp, brown, Silty, fine SAND; rootlets; trace carbonates
OTAY FORMATION (To)
Stiff to very stiff, dry, light grayish brown, fine Sandy SILTSTONE; very
thinly bedded
TRENCH TERMINATED AT 6 FEET
No groundwater encountered
SM
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-30,
Log of Trench T 11, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 11
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)540'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, dry to damp, brown to dark brown, Silty, fine SAND
-Trace carbonates
OTAY FORMATION (To)
Stiff, dry, light grayish brown, fine Sandy SILTSTONE to Silty fine
SANDSTONE; slightly cemented
-Decreased cohesive strength
TRENCH TERMINATED AT 7.5 FEET
No groundwater encountered
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-31,
Log of Trench T 12, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 12
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)510'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Soft, damp, dark brown, fine Sandy CLAY; trace rootlets
-Trace carbonates and krotovinas up to 8"
Soft, damp, brown, Silty, fine SAND
OTAY FORMATION (To)
Dense to very dense, damp, light grayish brown, Silty, fine-grained
SANDSTONE; moderately cemented
TRENCH TERMINATED AT 7.5 FEET
No groundwater encountered
T13-1
CL
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-32,
Log of Trench T 13, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 13
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)446'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Soft to firm, damp to moist, dark brown, fine Sandy CLAY
Medium dense, damp, white to light brown with lenses of Silty, fine SAND
OTAY FORMATION (To)
Dense, damp, light grayish brown, Silty, fine-grained SANDSTONE
-Becomes moderately cemented
TRENCH TERMINATED AT 8.5 FEET
No groundwater encountered
CL
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-33,
Log of Trench T 14, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 14
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)450'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Soft to firm, damp, dark brown, fine Sandy CLAY; rootlets
-Trace carbonates, white to very light brown
OTAY FORMATION (To)
Dense to very dense, damp, light grayish brown, Silty, fine-to medium-grained
SANDSTONE; moderately cemented
TRENCH TERMINATED AT 6.5 FEET
No groundwater encountered
CL
SC-SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-34,
Log of Trench T 15, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 15
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)405'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Soft to firm, damp, dark brown, fine Sandy CLAY; trace rootlets
-No rootlets
OTAY FORMATION (To)
Dense, light grayish brown and light brown, Clayey SANDSTONE; thinly
bedded, light brown Silty, fine-grained SANDSTONE; with low cohesive
strength
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
T6-1
CL
SC-SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-35,
Log of Trench T 16, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 16
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)415'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Firm, damp, dark brown, fine Sandy CLAY
Medium dense, dry, dark brown, Silty SAND
-Becomes Clayey SAND; with trace carbonates
-Becomes reddish brown, Silty SAND; little gravel up to 3"
OTAY FORMATION (To)
Medium dense to dense, dry, light brown to very light brown, Silty, fine-to
coarse-grained SANDSTONE; trace subangular gravel up to 3"; trace
carbonates
TRENCH TERMINATED AT 9.5 FEET
No groundwater encountered
T17-1
CL
SM
SC
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-36,
Log of Trench T 17, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 17
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)392'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Medium dense, damp to moist, dark brown, Clayey, fine to medium SAND ;
trace rootlets
-Clayey, fine to coarse SAND; gravel up to ½"
OTAY FORMATION (Tog)
Very dense, damp, light yellowish brown, medium-to coarse-grained
SANDSTONE; ("GRITSTONE"), trace subangular to subround gravel up to
1"
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
SC
SW
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-37,
Log of Trench T 18, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 18
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)370'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose to medium dense, damp, dark brown, Clayey, fine to medium SAND;
rootlets
-Trace carbonates
OTAY FORMATION (To)
Dense to very dense, damp, light yellowish brown, Silty, medium-to
coarse-grained SANDSTONE; trace carbonates
-Becomes very dense, grayish brown, fine-to coarse-grained SANDSTONE;
moderately cemented
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-38,
Log of Trench T 19, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 19
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-22-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)402'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp to moist, dark brown, Clayey, fine to medium SAND; trace
gravel up to 2"
OTAY FORMATION (Tog)
Very dense, damp, light yellowish brown, medium-to coarse-grained
SANDSTONE; ("GRITSTONE") subround to subangular gravel up to 3"
TRENCH TERMINATED AT 5 FEET
No groundwater encountered
SC
SW
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-39,
Log of Trench T 20, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 20
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)340'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose to medium dense, moist, dark brown, fine to medium Sandy CLAY;
some rootlets
-Trace carbonates
OTAY FORMATION (Tog)
Medium dense to dense, damp, light yellowish brown, Silty, medium-to
coarse-grained SANDSTONE
Dense, damp, light grayish brown, Silty, medium-to coarse-grained
SANDSTONE; ("GRITSTONE") subround to subangular gravel up to ½"
TRENCH TERMINATED AT 6 FEET
No groundwater encountered
CL
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-40,
Log of Trench T 21, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 21
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)358'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, damp to moist, light yellowish brown to dark brown, Clayey, fine to
medium SAND to Gravelly fine to coarse SAND; few roots,
subround to subangular gravel
-Thinly to moderately bedded
OTAY FORMATION (Tog)
Very dense, damp to moist, light yellowish brown, medium-to coarse -grained
SANDSTONE; ("GRITSTONE") trace gravel up to 1"
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
SC
SW
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-41,
Log of Trench T 22, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 22
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)324'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, dark brown, Clayey, fine to medium SAND; trace roots
and rootlets
OTAY FORMATION (Tog)
Very dense, dry, light yellowish brown, Silty, fine-to coarse-grained
SANDSTONE; ("GRITSTONE") few gravel up to approximately ½"
TRENCH TERMINATED AT 4 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-42,
Log of Trench T 23, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 23
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)350'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, moist, dark brown to brown, Clayey, fine to coarse SAND; trace gravel
-Becomes reddish brown
TERRACE DEPOSITS (Qt)
Very dense, moist, brown to reddish brown, fine-to coarse-grained
SANDSTONE; trace gravel up to 1"
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
T24-1
SC
SW
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-43,
Log of Trench T 24, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 24
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)314'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, dark brown, Clayey, fine to medium SAND; trace
gravel up to approximately 2"
-Becomes brown
TERRACE DEPOSITS (Qt)
Dense, dry, reddish brown, fine-to medium-grained SANDSTONE
Very dense, damp, reddish brown, Silty, fine-to coarse-grained
SANDSTONE; trace subrounded cobble up to approximately 5"
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
T25-1
SC
SM
SW
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-44,
Log of Trench T 25, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 25
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)315'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, dark brown, Clayey, fine to medium SAND; trace
subangular cobble up to 5"
TERRACE DEPOSITS (Qt)
Very dense, moist, dark reddish brown, fine-to coarse-grained SANDSTONE;
trace clay and subrounded gravel up to 2", subangular cobbles up to 5"
TRENCH TERMINATED AT 5.5 FEET
No groundwater encountered
T26-1
SC
SW
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-45,
Log of Trench T 26, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 26
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)310'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, dark brown, Clayey, fine to medium SAND
-Trace carbonates
OTAY FORMATION (Tog)
Very dense, damp, light yellowish brown, Silty, fine-to coarse-grained
SANDSTONE; ("GRITSTONE") slightly cemented; trace gravel 1"
TRENCH TERMINATED AT 5 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-46,
Log of Trench T 27, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 27
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)370'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, dark brown, Clayey, fine to medium SAND
-Trace carbonates
OTAY FORMATION (Tog)
Very dense, damp, light grayish brown to yellowish brown, Silty, fine-to
coarse-grained SANDSTONE; ("GRITSTONE") trace gravel up to
approximately 1"
TRENCH TERMINATED AT 5 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-47,
Log of Trench T 28, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 28
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)336'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, dry to damp, dark brown, Clayey, fine to medium SAND
-Becomes moist, Clayey, fine to medium SAND; cobbles ranging from
approximately 3" to approximately 18"
TERRACE DEPOSITS (Qt)
Very dense, damp to moist, light grayish brown, Silty, fine-to coarse-grained
SANDSTONE; trace gravel
TRENCH TERMINATED AT 12 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
Figure A-48,
Log of Trench T 29, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 29
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-23-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)235'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Medium dense, moist, dark brown, Clayey, fine to coarse SAND; trace gravel
Medium dense, damp, dark brown, Clayey, fine to coarse SAND; trace gravel
TERRACE DEPOSITS (Qt)
Dense, moist, reddish brown, Clayey, medium-to coarse-grained
SANDSTONE; trace gravel and cobbles up to 18" maximum dimension
TRENCH TERMINATED AT 17.5 FEET
No groundwater encountered
T30-1
SC
SC
SC
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
Figure A-49,
Log of Trench T 30, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 30
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
A. GASTELUM CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)219'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Medium dense, dry, dark grayish brown, Clayey, fine to medium SAND
TERRACE DEPOSITS (Qt)
Desne to very dense, moist, reddish brown to grayish brown, Clayey, fine-to
coarse-grained SANDSTONE; trace gravel and cobble; angular to rounded
cobble up to 12"
-Becomes wet, dark reddish brown
TRENCH TERMINATED AT 19 FEET
No groundwater encountered
T31-1
T31-2
SC
SC
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
Figure A-50,
Log of Trench T 31, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 31
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
A. GASTELUM CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)223'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, damp, grayish brown, Silty, fine to medium SAND
TERRACE DEPOSITS (Qt)
Medium dense, damp, brown to reddish brown, Clayey, fine-to coarse-grained
SANDSTONE; little gravel and rounded to angular cobble up to 12"
Dense, moist, reddish brown, Clayey, fine-to coarse-grained SANDSTONE;
little gravel and cobble; trace boulders up to 18"
-Becomes grayish brown
TRENCH TERMINATED AT 18 FEET
No groundwater encountered
T32-1 SM
SC
SC
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
Figure A-51,
Log of Trench T 32, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 32
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
A. GASTELUM CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)227'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose to medium dense, damp, dark grayish brown, fine to medium Sandy
CLAY; trace cobbles
TERRACE DEPOSITS (Qt)
Dense to very dense, moist, reddish brown, Clayey fine-to coarse-grained
SANDSTONE; little gravel and cobbles up to 18"
Dense to very dense, moist, pale light grayish brown, Silty, medium-to
coarse-grained SANDSTONE; little gravel, trace cobble and boulders up to
24", cemented
TRENCH TERMINATED AT 18 FEET
No groundwater encountered
T33-1
T33-2
CL
CL
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
16
18
Figure A-52,
Log of Trench T 33, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 33
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
A. GASTELUM CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-24-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)214'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, dry, dark brown, Silty, fine SAND; few rootlets
OTAY FORMATION (To)
Dense, dry, light yellowish brown, Silty, fine-to medium-grained
SANDSTONE; trace gravel, weakly cemented
-Strongly cemented
TRENCH TERMINATED AT 9.5 FEET
No groundwater encountered
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-53,
Log of Trench T 34, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 34
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
A. GASTELUM CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)420'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, damp, dark brown, Silty, fine SAND
OTAY FORMATION (To)
Dense to very dense, dry, light yellowish brown, Silty, fine-to medium-grained
SANDSTONE; trace gravel, moderately cemented
TRENCH TERMINATED AT 6.5 FEET
No groundwater encountered
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-54,
Log of Trench T 35, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 35
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)430'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, damp, dark brown, Silty, fine SAND; few rootlets
OTAY FORMATION (To)
Dense, dry, light yellowish brown, Silty, fine SANDSTONE; strongly
cemented
TRENCH TERMINATED AT 6 FEET
No groundwater encountered
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-55,
Log of Trench T 36, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 36
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)472'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, dry, dark brown, Silty, fine SAND; few rootlets
OTAY FORMATION (To)
Dense, dry, light yellowish brown, fine-to medium-grained SANDSTONE;
moderately cemented
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
SM
SW
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-56,
Log of Trench T 37, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 37
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)508'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, dry, dark brown, Silty, fine SAND; few rootlets
OTAY FORMATION (To)
Dense, dry, light yellowish brown, Silty, fine SANDSTONE; strongly
cemented, krotovinas to about 3 feet
Stiff, grayish brown, Silty CLAYSTONE
Dense, dry, light yellowish brown, Silty, fine SANDSTONE
TRENCH TERMINATED AT 9.5 FEET
No groundwater encountered
SM
SM
CL
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-57,
Log of Trench T 38, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 38
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)546'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Loose, damp, brown, Silty, fine to medium SAND; few rootlets, trace
carbonates and trace subangular gravel up to approximately 3"
-Medium dense, dark brown, Silty, fine to coarse SAND; few clay; few
rootlets
OTAY FORMATION (Tog)
Dense to very dense, damp, yellowish brown, Silty, fine-to coarse-grained
SANDSTONE; ("GRITSTONE") trace clay and gravel up to 3"
-No gravel
TRENCH TERMINATED AT 11 FEET
No groundwater encountered
T39-1
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
Figure A-58,
Log of Trench T 39, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 39
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)356'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp, dark brown, Silty, fine to medium SAND
OTAY FORMATION (To)
Hard, damp, whitish brown, fine-grained Sandy SILTSTONE
Very dense, damp, light gray, Silty, fine-grained SANDSTONE; massive
TRENCH TERMINATED AT 12.5 FEET
No groundwater encountered
SM
ML
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
Figure A-59,
Log of Trench T 40, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 40
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)420'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, damp, dark brown, Silty, fine SAND; rootlets
OTAY FORMATION (To)
Stiff, dry, light grayish brown, fine-grained Sandy SILTSTONE
Stiff, damp, brown, Silty CLAYSTONE; bentonite, approximately 3" thick
Stiff, dry, light grayish brown, fine-grained Sandy SILTSTONE
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
T41-1
SM
ML
CH
ML
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-60,
Log of Trench T 41, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
BACKHOE JD 455 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 41
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
E. MILLER CO
N
T
E
N
T
(
%
)
SAMPLE
NO.02-27-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)426'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Stiff, moist, dark brown, Sandy CLAY
TERRACE DEPOSIT (Qt)
Dense, moist to damp, light reddish brown, Silty, fine-to medium-grained
SANDSTONE, trace clay and subrounded cobbles
OTAY FORMATION (Tog)
Dense to very dense, damp, light grayish brown, fine-to coarse-grained Silty
SANDSTONE ("Gritstone")
-Abundant carbonates to about 6'
-Becomes slightly cemented
TRENCH TERMINATED AT 6.5 FEET
No groundwater encountered
T42-1
SC
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-61,
Log of Trench T 42, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 42
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-28-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)334'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, dark brown, Clayey, fine-to coarse SAND, trace
rootlets
-Abundant cobble within 2 feet
TERRACE DEPOSITS (Qt)
Dense, damp, reddish brown, Sandy CONGLOMERATE; pockets of grayish
brown, fine to coarse sand
-Abundant cobble up to 4" in maximum dimension
-Locally slight cemented
Very dense, damp, reddish brown, Silty, medium to-coarse grained
SANDSTONE
-Some subangular gravel and cobble
OTAY FORMATION (Tog)
Very dense, damp, light yellowish brown, fine-to coarse-grained
SANDSTONE; ("Gritstone"), slightly cemented
TRENCH TERMINATED AT 14 FEET
No groundwater encountered
SC
GP
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
Figure A-62,
Log of Trench T 43, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 43
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-28-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)432'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey SAND
OTAY FORMATION (Tog)
Highly weathered, medium dense, damp, whitish, Silty, fine-to coarse-grained
SANDSTONE; abundant carbonates
TRENCH TERMINATED AT 4.5 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-63,
Log of Trench T 44, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 44
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-28-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)348'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey SAND
OTAY FORMATION (Tog)
Highly weathered,Silty, medium- to coarse-grained SANDSTONE; slightly
cemented
TRENCH TERMINATED AT 3 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
Figure A-64,
Log of Trench T 45, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 45
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-28-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)336'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, moist, brown, Clayey, fine to medium SAND
TERRACE DEPOSITS (Qt)
Dense, moist, grayish brown, fine- to medium-grained SANDSTONE; highly
weathered; friable; pebble sized gravel
Dense, moist, grayish brown, fine- to medium-grained SANDSTONE, weakly
cemented
Dense, damp, moist, reddish brown, Clayey SANDSTONE to
CONGLOMERATE; approximately 20% to 30% cobble up to 4" diameter
TRENCH TERMINATED AT 14 FEET
No groundwater encountered
T46-1
T46-2
SC
SM
SM
SM-GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
Figure A-65,
Log of Trench T 46, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 46
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-28-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)324'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, brown, Clayey, fine to medium SAND
TERRACE DEPOSITS (Qt)
Stiff, moist, reddish brown, Sandy CLAY; common parting surfaces and
blocky texture
-Trace cobble
OTAY FORMATION (Tog)
Highly weathered, medium dense, moist, light grayish brown, Silty, fine-to
coarse -grained SANDSTONE; trace pinhole porosity
Dense, moist, light grayish to reddish brown, Silty, medium-to coarse-grained
SANDSTONE ("Gritstone") slightly cemented
TRENCH TERMINATED AT 8 FEET
No groundwater encountered
T47-1
T47-2
T47-3
SC
SC
SM
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-66,
Log of Trench T 47, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 47
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-28-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)334'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, moist, brown, Clayey, fine to medium SAND
OTAY FORMATION (Tog)
Dense, damp, grayish brown, Silty, fine-to coarse-grained SANDSTONE;
("Gritstone"); slightly cemented
TRENCH TERMINATED AT 4 FEET
No groundwater encountered
SC
SM
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-67,
Log of Trench T 48, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 48
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-28-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)340'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Stiff, moist, brown, Sandy CLAY
TERRACE DEPOSITS (Qt)
Medium dense, moist, reddish brown, Clayey, fine to medium-grained
SANDSTONE; trace pinhole porosity to approximately 8 feet
-Trace of carbonates and cobble
-Some burrows
-Becomes dense
Very dense, damp, reddish to gray brown, Silty, fine-to coarse SANDSTONE
to CONGLOMERATE; weakly cemented
-Approximately. 10% to 20% cobble and becomes moderately cemented
TRENCH TERMINATED AT 14 FEET
No groundwater encountered
SC
SC
SM-GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
Figure A-68,
Log of Trench T 49, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 49
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)328'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Stiff, dark reddish brown, Clayey, fine-to medium grained SAND; trace
rootlets and subrounded cobble
-Becomes reddish-brown with manganese oxide staining and trace pinhole
porosity
TERRACE DEPOSITS (Qt)
Dense, moist, reddish brown, Clayey, fine-to medium grained SANDSTONE;
little cobble and trace gravel
Very dense, damp, reddish brown, Sandy CONGLOMERATE, with pockets
of light brown, fine-to medium SAND
-Approximately. 20% to 30% cobble, difficult excavations
-Trench belling
TRENCH TERMINATED AT 10 FEET
No groundwater encountered
T50-1
SC
SM
GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
Figure A-69,
Log of Trench T 50, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 50
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)209'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Stiff, moist, dark, reddish brown, Sandy CLAY; trace rootlets and subrounded
cobble
TERRACE DEPOSIT (Qt)
Very dense, reddish brown, Silty SANDSTONE to Conglomerate
REFUSAL AT 4 FEET
No groundwater encountered
SC
SM-GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-70,
Log of Trench T 51, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 51
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)205'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Medium dense, moist, light grayish brown, Silty, fine to medium SAND; trace
carbonates
-Becomes dense
TERRACE DEPOSIT (Qt)
Very dense, moist, reddish brown, fine to coarse Sandy CONGLOMERATE;
approximately 20% to 30% cobble; moderately weakly cemented
TRENCH TERMINATED AT 6 FEET
No groundwater encountered
SM
GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-71,
Log of Trench T 52, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 52
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)210'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Medium dense, moist, olive brown to brown, Clayey, fine to medium SAND
TERRACE DEPOSIT (Qt)
Very dense, moist, reddish brown, fine to coarse Sandy CONGLOMERATE;
approximately 20% to 30% cobble; moderately weakly cemented
REFUSAL AT 3 FEET
No groundwater encountered
SC
GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
Figure A-72,
Log of Trench T 53, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 53
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)214'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Firm, moist, brown, Sandy, fine to medium SAND; trace rootlets and gravel
TERRACE DEPOSIT (Qt)
Medium dense, moist, reddish brown, Clayey, fine-to medium-grained
SANDSTONE; friable, trace pinhole, porosity
Very dense, damp, reddish brown, Sandy CONGLOMERATE; with pockets
of silty sand, moderately cemented
TRENCH TERMINATED AT 9 FEET
No groundwater encountered
SM
SC
GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
Figure A-73,
Log of Trench T 54, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 54
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)220'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
ALLUVIUM (Qal)
Medium dense, moist, reddish brown, Clayey, fine to coarse SAND
Stiff, moist, brown, Sandy CLAY; trace pinhole porosity and burrows
TERRACE DEPOSIT (Qt)
Dense to very dense, reddish brown, Sandy CONGLOMERATE; pockets of
silty sand; approximately 20%-30% cobble
REFUSAL AT 5 FEET
No groundwater encountered
SC
SC
GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
Figure A-74,
Log of Trench T 55, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 55
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)222'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Loose, dry, grayish, brown, Silty SAND; abundant rootlets and burrows
TERRACE DEPOSIT (Qt)
Stiff, moist, reddish brown, Sandy CLAY; abundant carbonates stringers
Dense, moist, reddish brown, fine-to coarse-grained SANDSTONE,
approximately 10% cobble; trace boulders up to 12 inches
Very dense, moist, reddish brown, CONGLOMERATE with pockets of silty
sand
TRENCH TERMINATED AT 14 FEET
No groundwater encountered
T56-1
SM
SC
SM
GP
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
8
10
12
14
Figure A-75,
Log of Trench T 56, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 56
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)230'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
TOPSOIL
Medium dense, dry, light reddish brown, Silty, fine-to medium SAND; trace
rootlets
TERRACE DEPOSIT (Qt)
Stiff, moist, reddish brown, Sandy CLAY; abundant cobble
Very dense, reddish brown, Sandy CONGLOMERATE; pockets of silty sand
Very stiff, reddish brown, Sandy CLAY, trace subangular gravel
TRENCH TERMINATED AT 7 FEET
No groundwater encountered
T57-1
SM
CL
GP
SC
... DISTURBED OR BAG SAMPLE
GEOCON
DEPTH
IN
FEET
0
2
4
6
Figure A-76,
Log of Trench T 57, Page 1 of 1
DR
Y
D
E
N
S
I
T
Y
(P
.
C
.
F
.
)
... DRIVE SAMPLE (UNDISTURBED)
JD 555 PE
N
E
T
R
A
T
I
O
N
RE
S
I
S
T
A
N
C
E
(B
L
O
W
S
/
F
T
.
)
TRENCH T 57
... CHUNK SAMPLE
DATE COMPLETED
... SAMPLING UNSUCCESSFUL
SOIL
CLASS
(USCS)
GR
O
U
N
D
W
A
T
E
R
M. ERTWINE CO
N
T
E
N
T
(
%
)
SAMPLE
NO.08-29-2012
SAMPLE SYMBOLS
MO
I
S
T
U
R
E
BY:EQUIPMENT
ELEV. (MSL.)237'
G1006-11-05.GPJ
MATERIAL DESCRIPTION
LI
T
H
O
L
O
G
Y
... STANDARD PENETRATION TEST
... WATER TABLE OR ... SEEPAGE
NOTE:
PROJECT NO.
THE LOG OF SUBSURFACE CONDITIONS SHOWN HEREON APPLIES ONLY AT THE SPECIFIC BORING OR TRENCH LOCATION AND AT THE DATE INDICATED. IT
IS NOT WARRANTED TO BE REPRESENTATIVE OF SUBSURFACE CONDITIONS AT OTHER LOCATIONS AND TIMES.
G1006-11-05
APPENDIX B
APPENDIX B
PREVIOUS LABORATORY TESTING
FOR
OTAY RANCH VILLAGE 8 WEST
CHULA VISTA, CALIFORNIA
PROJECT NO. G1006-52-05
Geocon Project No. G1006-52-05 B- 1 - September 30, 2022
Revised May 5, 2023
APPENDIX B
PREVIOUS LABORATORY TESTING
We performed laboratory tests during our previous geotechnical investigation in accordance with generally
accepted test methods of the American Society for Testing and Materials (ASTM) or other suggested
procedures. Selected soil samples were analyzed for in-situ dry density and moisture content, maximum
dry density and optimum moisture content, direct shear strength, expansion potential, water-soluble sulfate,
Atterberg Limits, R-Value, and gradation. The results of the laboratory tests are presented on Tables B-I
through B-VI and Figure B-1. The in-place dry density and moisture content of the samples tested are
presented on the boring logs in Appendix A.
TABLE B-I
SUMMARY OF LABORATORY MAXIMUM DRY DENSITY
AND OPTIMUM MOISTURE CONTENT TEST RESULTS
ASTM D 1557
Sample No. Description (Geologic Unit) Maximum Dry
Density (pcf)
Optimum Moisture
Content (% dry wt.)
B1-1 (To) Brown, Clayey SILT 114.1 16.3
B2-2 (To) Brown, Silty, fine SAND 112.7 15.1
B7-3 (To) Brown, Silty, fine SAND 116.2 13.8
T16-1 (Qal) Dark gray, Silty CLAY with trace gravel 114.0 15.3
T30-1 (Qal) Dark yellowish brown, Clayey, fine to
medium SAND 134.5 7.7
TABLE B-II
SUMMARY OF LABORATORY DIRECT SHEAR TEST RESULTS
ASTM D 3080
Sample No.
(Geologic Unit)
Dry Density
(pcf)
Moisture Content (%) Peak [Ultimate]
Cohesion (psf)
Peak [Ultimate]
Angle of Shear
Resistance (degrees) Initial After Test
B1-6 (To) 111.1 13.9 22.3 185 [50] 41 [41]
B1-8 (To) 89.1 34.2 42.7 295 [0] 27 [29]
B2-2* (To) 103.2 12.7 25.8 120 [20] 29 [30]
B3-2 (To) 104.1 19.9 28.9 590 [165] 34 [36]
B3-5 (To) 108.3 15.1 24.9 650 [235] 32 [36]
B4-2 (To) 116.6 14.1 20.3 70 [0] 41 [40]
B7-3* (To) 103.6 14.6 21.7 335 [30] 28 [30]
*Sample remolded to a dry density of approximately 90 percent of the laboratory maximum dry density near optimum
moisture content.
Geocon Project No. G1006-52-05 B- 2 - September 30, 2022
Revised May 5, 2023
TABLE B-III
SUMMARY OF LABORATORY EXPANSION INDEX TEST RESULTS
ASTM D 4829
Sample No.
(Geologic
Unit)
Moisture Content (%) Dry
Density
(pcf)
Expansion
Index
Expansion
Classification
2022
Expansion
Classification Before Test After Test
B1-1 (To) 10.8 26.4 102.2 68 Medium Expansive
B2-2 (To) 12.6 28.2 98.6 62 Medium Expansive
T16-1 (Qal) 12.6 29.6 100.7 82 Medium Expansive
T30-1 (Qal) 8.7 16.3 114.2 19 Very Low Non-Expansive
TABLE B-IV
SUMMARY OF LABORATORY WATER-SOLUBLE SULFATE TEST RESULTS
CALIFORNIA TEST NO. 417
Sample No.
(Geologic Unit)
Water-Soluble
Sulfate (%)
Water-Soluble
Sulfate (ppm)
ACI 318 Sulfate
Exposure
B1-1 (To) 0.028 275 Not Applicable (S0)
B2-2 (To) 0.000 2 Not Applicable (S0)
TABLE B-V
SUMMARY OF LABORATORY ATTERBERG LIMITS TEST RESULTS
ASTM D 4318
Sample No. (Geologic
Unit) Liquid Limit Plastic Limit Plasticity Index
B1-9 (Tob) 77 37 40
B3-6 (To) 117 61 56
B9-2 (To) 105 51 54
TABLE B-VI
SUMMARY OF LABORATORY RESISTANCE VALUE (R-VALUE) TEST RESULTS
ASTM D 2844
Sample No. (Geologic Unit) R-Value
B3-4 (To) 15
0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110
3/8"4
30.0 117
PROJECT NO. G1006-11-02
U. S. STANDARD SIEVE SIZE
COARSE
3"3/4"1-1/2"8 16 20 30 40
37
51
PL
54
FINE
NAT WC
PE
R
C
E
N
T
F
I
N
E
R
B
Y
W
E
I
G
H
T
105
77
18.0
(MH) SILT33.0
PI
COARSE
56
GRAVEL
61
40
G1006-11-02.GPJ
B1-9
CHULA VISTA, CALIFORNIA
(MH) SILT
SAND
MEDIUM
5060 100 200
SAMPLE
GEOCON
SILT OR CLAYFINE
GRAIN SIZE IN MILLIMETERS
CLASSIFICATION
B3-6
B9-2
LL
(MH) SILT
10
DEPTH (ft)
OTAY RANCH VILLAGE 8
Figure B-1
GRADATION CURVE
APPENDIX C
Geocon Project No. G1006-52-05 C- 1 - September 30, 2022
Revised May 5, 2023
APPENDIX C
SLOPE STABILITY ANALYSES
We performed slope stability analyses using a two-dimensional computer program GeoStudio2018 created
by Geo-Slope International Ltd. We analyzed the critical modes of potential slip surfaces including
rotational-mode and block-mode based on Spencer’s method. The soil parameters used, case conditions,
and the calculated factors of safety were presented herein. Plots of analyses’ results, including the soil
stratigraphy, potential failure surfaces, and calculated Factors of Safety, are included in this appendix.
We evaluated the shear strength parameters for the existing geologic features from laboratory direct shear
and residual shear tests on samples obtained during our field investigation and on samples obtained from
other investigations in the area in accordance with ASTM D 3080. We performed direct shear tests on
samples of the Terrace Deposits, and the Otay Formation. The geologic units encountered and the shear
strength properties used in the analyses is presented on Table C-I.
TABLE C-I
SUMMARY OF SOIL PROPERTIES USED FOR SLOPE STABILITY ANALYSES
Geologic Unit/Material Density
(pcf)
Cohesion
(psf)
Friction Angle
(degrees)
Compacted Fill (Qcf) 125 250 28
Otay Formation (To) 130 350 34
Otay Formation (Tog) 130 350 34
Otay Formation Bentonite 120 30 6
We selected Geologic Cross-Sections A-A′ through H-H′ to perform the slope stability analyses. Table C-
II provides a summary of cases analyzed and calculated Factors of Safety. A minimum Factor of Safety of
1.5 under static conditions is currently required by the City of Chula Vista for slope stability. Figures C-1
through C-34 present the results of slope stability analyses generated by GeoStudio 2018. As discussed
herein, we encountered claystone layers in several of the exploratory borings within the Otay Formation.
The claystone possesses relatively low shear strengths and may be prone to slope instability if exposed in
cut slopes. A factor of safety of 1.5 for all static slopes is currently required by the City of Chula Vista to
build structures above or below a slope.
Geocon Project No. G1006-52-05 C- 2 - September 30, 2022
Revised May 5, 2023
TABLE C-II
SUMMARY OF SLOPE STABILITY ANALYSES
Figure
Number
Cross
Section Condition of Slope Stability Analyses Calculated
Factor of Safety
B-1 A-A′
MSE Wall: Geogrids = Miragrid 5XT spaced at 2 ft. intervals,
Lengths=20 ft..; Fill behind face of wall = minimum 20 ft. wide at
bottom; Block-mode analysis along bentonite, static condition
1.95
B-2 A-A′
MSE Wall: Geogrids = Miragrid 5XT spaced at 2 ft. intervals,
Lengths=20 ft..; Fill behind face of wall = minimum 20 ft. wide at
bottom; Block-mode analysis along upper bentonite behind fill, static
condition
3.23
B-3 A-A′
MSE Wall: Geogrids = Miragrid 5XT spaced at 2 ft. intervals,
Lengths=20 ft..; Fill behind face of wall = minimum 20 ft. wide at
bottom; Rotational-mode analysis, static condition
1.63
B-4 B-B′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=25 ft..;
Fill behind face of wall = minimum 25 ft. wide at bottom; Rotational-
mode analysis, static condition
1.55
B-5 B-B′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=25 ft..;
Fill behind face of wall = minimum 25 ft. wide at bottom; Block-
mode analysis along bentonite behind wall, static condition
1.75
B-6 B-B′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=25 ft..;
Fill behind face of wall = minimum 25 ft. wide at bottom; Block-
mode analysis along upper bentonite behind wall, static condition
2.10
B-7 B-B′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=25 ft..;
Fill behind face of wall = minimum 25 ft. wide at bottom; Block-
mode analysis along bentonite below wall, static condition
1.97
B-8 C-C′ Upper Slope; Proposed Pad Undercut of bentonite in front of slope,
Block-mode analysis along bentonite, static condition 1.80
B-9 C-C′ Upper Slope; Proposed Pad Undercut of bentonite in front of slope,
Rotational-mode analysis, static condition 2.66
B-10 C-C′ Lower Slope; Rotational-mode analysis, static condition 2.07
B-11 D-D′ Upper Slope; Block-mode analysis along bentonite, static condition 1.22
B-12 D-D′ Upper Slope; 20 ft. wide buttress; Block-mode analysis along
bentonite, static condition 1.53
B-13 D-D′ Upper Slope; 20 ft. wide buttress; Rotational-mode analysis, static
condition 2.16
B-14 D-D′ Lower Slope; MSE Wall: Geogrids = Miragrid 5XT spaced at 2 ft.
intervals, Lengths=10 ft..; Rotational-mode analysis, static condition 1.98
B-15 E-E′
MSE Wall: Geogrids = Miragrid 5XT spaced at 2 ft. intervals,
Lengths = 8 ft..; Fill behind face of wall = minimum 8 ft. wide at
bottom; Block-mode analysis along bentonite, static condition
1.34
B-16 E-E′
MSE Wall: Geogrids = Miragrid 5XT spaced at 2 ft. intervals,
Lengths = 8 ft..; Minimum 30 ft. wide buttress behind face of wall at
bottom; Block-mode analysis along bentonite, static condition
1.58
Geocon Project No. G1006-52-05 C- 3 - September 30, 2022
Revised May 5, 2023
Figure
Number
Cross
Section Condition of Slope Stability Analyses Calculated
Factor of Safety
B-17 E-E′
MSE Wall: Geogrids = Miragrid 5XT spaced at 2 ft. intervals,
Lengths = 8 ft..; Minimum 30 ft. wide buttress behind face of wall at
bottom; Rotational-mode analysis, static condition
1.69
B-18 F-F′ Lower slope; Block-mode analysis along lower bentonite, static
condition 1.31
B-19 F-F′ Lower slope; 15 ft. wide buttress within limits of grading; Block-
mode analysis along lower bentonite, static condition 0.99
B-20 F-F′
Lower slope; 15 ft. wide buttress within limits of grading; Required
Setback where Factor of Safety = 1.50; Block-mode analysis along
lower bentonite, static condition
1.50
B-21 F-F′ Lower slope; 15 ft. wide buttress outside of limits of grading;
Block-mode analysis along lower bentonite, static condition 1.54
B-22 G-G′ Block-mode analysis along bentonite, static condition 1.89
B-23 G-G′ Rotational-mode analysis, static condition 3.48
B-24 H-H′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=20 ft..;
Fill behind face of wall = minimum 20 ft. wide at bottom; Rotational-
mode analysis, static condition
1.54
B-25 H-H′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=20 ft..;
Fill behind face of wall = minimum 20 ft. wide at bottom; Block-
mode analysis along bentonite below wall, static condition
2.31
B-26 H-H′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=20 ft..;
Fill behind face of wall = minimum 20 ft. wide at bottom; Block-
mode analysis along lower bentonite behind wall, static condition
1.60
B-27 H-H′
MSE Wall: Bottom 4 Geogrids = Miragrid 10XT & Upper
Geogrids=Miragrid 8XT, spaced at 2 ft. intervals, Lengths=20 ft..;
Fill behind face of wall = minimum 20 ft. wide at bottom; Block-
mode analysis along upper bentonite behind wall, static condition
1.73
B-28 H-H′ Slope at limits of grading; Block-mode analysis along lower
bentonite, static condition 0.99
B-29 H-H′ Slope at limits of grading; Block-mode analysis along upper
bentonite, static condition 0.31
B-30 H-H′ Slope at limits of grading; 20 ft. wide buttress; Block-mode analysis
along lower bentonite, static condition 1.78
B-31 H-H′ Slope at limits of grading; 20 ft. wide buttress; Block-mode analysis
along upper bentonite, static condition 2.12
B-32 H-H′ Slope at limits of grading; 20 ft. wide buttress; Rotational-mode
analysis, static condition 1.94
B-33 N/A 2:1 fill slope, 50 feet high, rotational-mode analysis, static condition 1.67
B-34 N/A 2:1 cut slope, 45 feet high, rotational-mode analysis, static condition 2.22
1.95
Distance
-150 -100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
Tog Tog Tog
To
Proposed Undercut
To
To
Extended for Analysis
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 20 ft.
W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\A-A'\A-A'_Case1.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section A-A'
File Name: A-A'_Case1.gsz
Date: 09/26/2022, Time: 09:17:56 AM
A A'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
3.23
Distance
-150 -100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
Tog Tog Tog
To
Proposed Undercut
To
To
Extended for Analysis
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 20 ft.
W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\A-A'\A-A'_Case2.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section A-A'
File Name: A-A'_Case2.gsz
Date: 09/26/2022, Time: 09:30:31 AM
A A'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
1.63
Distance
-150 -100 -50 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
Tog Tog Tog
To
Proposed Undercut
To
To
Extended for Analysis
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 20 ft.
W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\A-A'\A-A'_Case3.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section A-A'
File Name: A-A'_Case3.gsz
Date: 09/26/2022, Time: 09:33:24 AM
A A'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
1.55
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450 1,500 1,550 1,600 1,650 1,700 1,750 1,800 1,850
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To
Tob (bentonite)To
To
Proposed Grade
Existing Grade
Tog Tog Tog
To
To
Tog
To
To
Proposed Undercut for Bentonite
Proposed MSE Wall
Length = 25 ft.
Bottom 4 Grids = Miragrid 10XT
Upper Grids = Miragrid 8XT
spaced at 2 ft. intervals
W=25'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\B-B'\B-B'_Case1a.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section B-B'
File Name: B-B'_Case1a.gsz
Date: 09/26/2022, Time: 09:43:30 AM
B B'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Rotational-mode Analysis
1.75
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450 1,500 1,550 1,600 1,650 1,700 1,750 1,800 1,850
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To
Tob (bentonite)To
To
Proposed Grade
Existing Grade
Tog Tog Tog
To
To
Tog
To
To
Proposed Undercut for Bentonite
Proposed MSE Wall
Length = 25 ft.
Bottom 4 Grids = Miragrid 10XT
Upper Grids = Miragrid 8XT
spaced at 2 ft. intervals
W=25'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\B-B'\B-B'_Case2a.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section B-B'
File Name: B-B'_Case2a.gsz
Date: 09/26/2022, Time: 09:51:31 AM
B B'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
2.10
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450 1,500 1,550 1,600 1,650 1,700 1,750 1,800 1,850
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To
Tob (bentonite)To
To
Proposed Grade
Existing Grade
Tog Tog Tog
To
To
Tog
To
To
Proposed Undercut for Bentonite
Proposed MSE Wall
Length = 25 ft.
Bottom 4 Grids = Miragrid 10XT
Upper Grids = Miragrid 8XT
spaced at 2 ft. intervals
W=25'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\B-B'\B-B'_Case3a.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section B-B'
File Name: B-B'_Case3a.gsz
Date: 09/26/2022, Time: 09:52:24 AM
B B'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
1.97
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450 1,500 1,550 1,600 1,650 1,700 1,750 1,800 1,850
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To
Tob (bentonite)To
To
Proposed Grade
Existing Grade
Tog Tog Tog
To
To
Tog
To
To
Proposed Undercut for Bentonite
Proposed MSE Wall
Length = 25 ft.
Bottom 4 Grids = Miragrid 10XT
Upper Grids = Miragrid 8XT
spaced at 2 ft. intervals
W=25'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\B-B'\B-B'_Case4a.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section B-B'
File Name: B-B'_Case4a.gsz
Date: 09/26/2022, Time: 09:56:40 AM
B B'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Rotational-mode Analysis
1.80
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To Tob (bentonite)To To
Existing Grade
Tog Tog Tog
Qcf
Proposed Grade
Proposed Grade
To To
Proposed Underecut for Bentonite
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\C-C'\C-C'_Case1.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section C-C'
File Name: C-C'_Case1.gsz
Date: 09/23/2022, Time: 11:45:17 PM
C C'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
2.66
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To Tob (bentonite)To To
Existing Grade
Tog Tog Tog
Qcf
Proposed Grade
Proposed Grade
To To
Proposed Underecut for Bentonite
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\C-C'\C-C'_Case2.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section C-C'
File Name: C-C'_Case2.gsz
Date: 09/26/2022, Time: 08:26:38 AM
C C'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Rotational-mode Analysis
2.07
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350 1,400 1,450
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
250
300
350
400
450
500
550
600
650
To Tob (bentonite)To To
Existing Grade
Tog Tog Tog
Qcf
Proposed Grade
Proposed Grade
To To
Proposed Underecut for Bentonite
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\C-C'\C-C'_Case3.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section C-C'
File Name: C-C'_Case3.gsz
Date: 09/26/2022, Time: 10:23:06 AM
C C'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Rotational-mode Analysis
1.22
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tob (bentonite)
Existing Grade
Proposed Grade
To
ToTo
Tog
Tog
Tog
To
Qcf
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\D-D'\D-D'_Case 1.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section D-D'
File Name: D-D'_Case 1.gsz
Date: 09/26/2022, Time: 10:26:10 AM
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
D D'
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
1.53
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tob (bentonite)
Existing Grade
Proposed Grade
To
ToTo
Tog
Tog
Tog
To
Qcf
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\D-D'\D-D'_Case 2.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section D-D'
File Name: D-D'_Case 2.gsz
Date: 09/27/2022, Time: 02:48:35 PM
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
D D'
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
w/ 20 ft. Buttress
2.16
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tob (bentonite)
Existing Grade
Proposed Grade
To
ToTo
Tog
Tog
Tog
To
Qcf
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\D-D'\D-D'_Case 3.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section D-D'
File Name: D-D'_Case 3.gsz
Date: 09/27/2022, Time: 02:53:15 PM
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
D D'
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
w/ 20 ft. Buttress
1.98
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tob (bentonite)
Existing Grade
Proposed Grade
To
ToTo
Tog
Tog
Tog
To
Qcf
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\D-D'\D-D'_Case 4.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section D-D'
File Name: D-D'_Case 4.gsz
Date: 09/27/2022, Time: 02:55:41 PM
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
D D'
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
w/ 25 ft. Buttress
1.34
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Existing Grade
Proposed Grade
Qcf To
To To To
Tog Tog Tog
Tob (bentonite)
To
QcfQcf
Qcf
Proposed MSE Wall
Miragrid 5XT; Spaced at 2 ft. Intervals
Length = 8 ft.
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\E-E'\E-E'_Case1.gsz
E E'
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section E-E'
File Name: E-E'_Case1.gsz
Date: 09/26/2022, Time: 12:58:31 PM
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
1.58
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Existing Grade
Proposed Grade
Qcf To
To To To
Tog Tog Tog
Tob (bentonite)
To
QcfQcf
Qcf
Proposed MSE Wall
Miragrid 5XT; Spaced at 2 ft. Intervals
Length = 8 ft.
Approx. Limits
of
Grading
8 ft. grids
1:1 backcut
13 ft.
addt'l
Buttress
30 ft. total buttress behind MSE wall face
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\E-E'\E-E'_Case2.gsz
E E'
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section E-E'
File Name: E-E'_Case2.gsz
Date: 09/26/2022, Time: 12:57:35 PM
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
w/ 30 ft. Wide Total Buttress (benched cut)
1.69
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050 1,100 1,150 1,200 1,250 1,300 1,350
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Existing Grade
Proposed Grade
Qcf To
To To To
Tog Tog Tog
Tob (bentonite)
To
QcfQcf
Qcf
Proposed MSE Wall
Miragrid 5XT; Spaced at 2 ft. Intervals
Length = 8 ft.
Approx. Limits
of
Grading
8 ft. grids
1:1 backcut
13 ft.
addt'l
Buttress
30 ft. total buttress behind MSE wall face
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\E-E'\E-E'_Case3.gsz
E E'
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section E-E'
File Name: E-E'_Case3.gsz
Date: 09/27/2022, Time: 03:05:27 PM
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Rotational-mode Analysis
w/ 30 ft. Wide Total Buttress (benched cut)
1.31
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tog Tog
To To
Tob (bentonite)
ToTo
Proposed GradeExisting Grade
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\F-F'\F-F'_Case1.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section F-F'
File Name: F-F'_Case1.gsz
Date: 09/26/2022, Time: 01:12:41 PM
F F'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
0.99
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tog Tog
To To
Tob (bentonite)
ToTo
Proposed GradeExisting Grade
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.
Approx. Limits
of
Grading
W=15'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\F-F'\F-F'_Case2.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section F-F'
File Name: F-F'_Case2.gsz
Date: 09/27/2022, Time: 11:11:28 PM
F F'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
1.50
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tog Tog
To To
Tob (bentonite)
ToTo
Proposed GradeExisting Grade
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.
Approx. Limits
of
Grading
Setback Where
FOS = 1.5
(Sta. 8+77)
W=15'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\F-F'\F-F'_Case3.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section F-F'
File Name: F-F'_Case3.gsz
Date: 09/27/2022, Time: 11:18:28 PM
F F'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
Setback Where FOS=1.5
1.54
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1,000 1,050
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
El
e
v
a
t
i
o
n
200
250
300
350
400
450
500
550
600
Tog Tog
To To
Tob (bentonite)
ToTo
Proposed GradeExisting Grade
Proposed MSE Wall
Miragrid 5XT; spaced at 2 ft. intervals
Length = 10 ft.
Approx. Limits
of
Grading
W = 15 ft.
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\F-F'\F-F'_Case4.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section F-F'
File Name: F-F'_Case4.gsz
Date: 09/27/2022, Time: 03:16:26 PM
F F'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Tog 130 350 34
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite
Buttress Outside Limits of Grading; width = 15 ft.
1.89
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)To
To
Proposed Grade
Existing Grade
SR-125
To To
To
To
To To
To
To
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\G-G'\G-G'_Case1.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section G-G'
File Name: G-G'_Case1.gsz
Date: 09/26/2022, Time: 01:23:37 PM
G G'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Static Condition
Block-mode Analysis Along Bentonite Layer
3.48
Distance
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)To
To
Proposed Grade
Existing Grade
SR-125
To To
To
To
To To
To
To
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\G-G'\G-G'_Case2.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section G-G'
File Name: G-G'_Case2.gsz
Date: 09/26/2022, Time: 01:32:18 PM
G G'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Static Condition
Rotational-mode Analysis
1.54
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case1.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
File Name: H-H'_Case1.gsz
Date: 09/26/2022, Time: 01:56:06 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Rotational Mode Analysis - MSE Wall
W=20'
2.31
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case2.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section H-H'
File Name: H-H'_Case2.gsz
Date: 09/26/2022, Time: 01:57:49 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Block-mode Analysis Along Bentonite - Below MSE Wall
W=20'
1.60
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case3.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section H-H'
File Name: H-H'_Case3.gsz
Date: 09/26/2022, Time: 02:06:07 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Block-mode Analysis Along Bentonite - Behind MSE Wall
W=20'
1.73
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case4.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section H-H'
File Name: H-H'_Case4.gsz
Date: 09/26/2022, Time: 02:09:09 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Block-mode Analysis Along Bentonite - Behind MSE Wall
W=20'
0.99
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case5.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-11-05
Section H-H'
File Name: H-H'_Case5.gsz
Date: 09/26/2022, Time: 02:14:22 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Block-mode Analysis Along Bentonite
W=20'
0.31
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case6.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section H-H'
File Name: H-H'_Case6.gsz
Date: 09/27/2022, Time: 10:12:55 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Block-mode Analysis Along Bentonite
W=20'
1.78
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case7.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-11-05
Section H-H'
File Name: H-H'_Case7.gsz
Date: 09/27/2022, Time: 10:36:56 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Block-mode Analysis Along Bentonite
W=20'
2.12
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
W=20'W=20'
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case8.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-11-05
Section H-H'
File Name: H-H'_Case8.gsz
Date: 09/27/2022, Time: 10:33:05 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Block-mode Analysis Along Bentonite
1.94
Distance
-50 0 50 100 150 200 250 300 350 400 450 500 550 600
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
El
e
v
a
t
i
o
n
350
400
450
500
550
600
650
To
To
Tob (bentonite)
To
To
Proposed Grade
Existing Grade
SR 125
To
To
To
To
To
QcfTo
Proposed MSE Wall
Length = 20 ft.
Bottom 4 grids = Miragrid 10XT
Upper grids = Miragrid 8XT
spaced at 2 ft. intervals
Extended
for
Analysis
Approx. Limits
of
Grading
W=20 ft.
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\H-H'\H-H'_Case9.gsz
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
Section H-H'
File Name: H-H'_Case9.gsz
Date: 09/26/2022, Time: 02:53:51 PM
HH'
Material Properties:
Color Name Unit
Weight
(pcf)
Cohesion'
(psf)
Phi'
(°)
Qcf 125 250 28
To 130 350 34
Tob
(bentonite)
120 30 6
Proposed Grade
Rotational-mode Analysis
w/ 20 ft. Wide Buttress
W=20'
1.67
Distance
0 100 200
El
e
v
a
t
i
o
n
0
10
20
30
40
50
60
70
80
90
100
El
e
v
a
t
i
o
n
0
10
20
30
40
50
60
70
80
90
100
H = 50 feet1
Qcf
Qcf
2
Qcf
Proposed Grade
Fill Slope
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
File Name: Fill Slope H=50.gsz
Date: 09/28/2022, Time: 09:44:14 PM
Material Properties:
Color Name Unit Weight
(pcf)
Cohesion'
(psf)
Phi' (°)
Qcf 125 250 28
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\
50 ft. High Fill Slope
2.22
Distance
0 100 200
El
e
v
a
t
i
o
n
0
10
20
30
40
50
60
70
80
90
100
El
e
v
a
t
i
o
n
0
10
20
30
40
50
60
70
80
90
100
H = 45 feet1
To
To
2
Proposed Grade
Cut Slope
Project Name: Otay Ranch Village 8
Project No. G1006-52-05
File Name: Cut Slope H=45.gsz
Date: 09/28/2022, Time: 09:51:43 PM
Material Properties:
Color Name Unit Weight
(pcf)
Cohesion'
(psf)
Phi' (°)
To 130 350 34
S:\Engineering and Geology\ENGINEER PROGRAMS, GUIDES, ETC\EngrgPrg\GEO-SLOPE2018\G1006-52-05\2022-09-04_V8E Update\
45 ft. High Cut Slope
APPENDIX D
APPENDIX D
RECOMMENDED GRADING SPECIFICATIONS
FOR
OTAY RANCH VILLAGE 8 WEST
CHULA VISTA, CALIFORNIA
PROJECT NO. G1006-52-05
GI rev. 07/2015
RECOMMENDED GRADING SPECIFICATIONS
1. GENERAL
1.1 These Recommended Grading Specifications shall be used in conjunction with the
Geotechnical Report for the project prepared by Geocon. The recommendations contained
in the text of the Geotechnical Report are a part of the earthwork and grading specifications
and shall supersede the provisions contained hereinafter in the case of conflict.
1.2 Prior to the commencement of grading, a geotechnical consultant (Consultant) shall be
employed for the purpose of observing earthwork procedures and testing the fills for
substantial conformance with the recommendations of the Geotechnical Report and these
specifications. The Consultant should provide adequate testing and observation services so
that they may assess whether, in their opinion, the work was performed in substantial
conformance with these specifications. It shall be the responsibility of the Contractor to
assist the Consultant and keep them apprised of work schedules and changes so that
personnel may be scheduled accordingly.
1.3 It shall be the sole responsibility of the Contractor to provide adequate equipment and
methods to accomplish the work in accordance with applicable grading codes or agency
ordinances, these specifications and the approved grading plans. If, in the opinion of the
Consultant, unsatisfactory conditions such as questionable soil materials, poor moisture
condition, inadequate compaction, and/or adverse weather result in a quality of work not in
conformance with these specifications, the Consultant will be empowered to reject the
work and recommend to the Owner that grading be stopped until the unacceptable
conditions are corrected.
2. DEFINITIONS
2.1 Owner shall refer to the owner of the property or the entity on whose behalf the grading
work is being performed and who has contracted with the Contractor to have grading
performed.
2.2 Contractor shall refer to the Contractor performing the site grading work.
2.3 Civil Engineer or Engineer of Work shall refer to the California licensed Civil Engineer
or consulting firm responsible for preparation of the grading plans, surveying and verifying
as-graded topography.
2.4 Consultant shall refer to the soil engineering and engineering geology consulting firm
retained to provide geotechnical services for the project.
GI rev. 07/2015
2.5 Soil Engineer shall refer to a California licensed Civil Engineer retained by the Owner,
who is experienced in the practice of geotechnical engineering. The Soil Engineer shall be
responsible for having qualified representatives on-site to observe and test the Contractor's
work for conformance with these specifications.
2.6 Engineering Geologist shall refer to a California licensed Engineering Geologist retained
by the Owner to provide geologic observations and recommendations during the site
grading.
2.7 Geotechnical Report shall refer to a soil report (including all addenda) which may include
a geologic reconnaissance or geologic investigation that was prepared specifically for the
development of the project for which these Recommended Grading Specifications are
intended to apply.
3. MATERIALS
3.1 Materials for compacted fill shall consist of any soil excavated from the cut areas or
imported to the site that, in the opinion of the Consultant, is suitable for use in construction
of fills. In general, fill materials can be classified as soil fills, soil-rock fills or rock fills, as
defined below.
3.1.1 Soil fills are defined as fills containing no rocks or hard lumps greater than
12 inches in maximum dimension and containing at least 40 percent by weight of
material smaller than ¾ inch in size.
3.1.2 Soil-rock fills are defined as fills containing no rocks or hard lumps larger than
4 feet in maximum dimension and containing a sufficient matrix of soil fill to allow
for proper compaction of soil fill around the rock fragments or hard lumps as
specified in Paragraph 6.2. Oversize rock is defined as material greater than
12 inches.
3.1.3 Rock fills are defined as fills containing no rocks or hard lumps larger than 3 feet
in maximum dimension and containing little or no fines. Fines are defined as
material smaller than ¾ inch in maximum dimension. The quantity of fines shall be
less than approximately 20 percent of the rock fill quantity.
3.2 Material of a perishable, spongy, or otherwise unsuitable nature as determined by the
Consultant shall not be used in fills.
3.3 Materials used for fill, either imported or on-site, shall not contain hazardous materials as
defined by the California Code of Regulations, Title 22, Division 4, Chapter 30, Articles 9
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and 10; 40CFR; and any other applicable local, state or federal laws. The Consultant shall
not be responsible for the identification or analysis of the potential presence of hazardous
materials. However, if observations, odors or soil discoloration cause Consultant to suspect
the presence of hazardous materials, the Consultant may request from the Owner the
termination of grading operations within the affected area. Prior to resuming grading
operations, the Owner shall provide a written report to the Consultant indicating that the
suspected materials are not hazardous as defined by applicable laws and regulations.
3.4 The outer 15 feet of soil-rock fill slopes, measured horizontally, should be composed of
properly compacted soil fill materials approved by the Consultant. Rock fill may extend to
the slope face, provided that the slope is not steeper than 2:1 (horizontal:vertical) and a soil
layer no thicker than 12 inches is track-walked onto the face for landscaping purposes. This
procedure may be utilized provided it is acceptable to the governing agency, Owner and
Consultant.
3.5 Samples of soil materials to be used for fill should be tested in the laboratory by the
Consultant to determine the maximum density, optimum moisture content, and, where
appropriate, shear strength, expansion, and gradation characteristics of the soil.
3.6 During grading, soil or groundwater conditions other than those identified in the
Geotechnical Report may be encountered by the Contractor. The Consultant shall be
notified immediately to evaluate the significance of the unanticipated condition.
4. CLEARING AND PREPARING AREAS TO BE FILLED
4.1 Areas to be excavated and filled shall be cleared and grubbed. Clearing shall consist of
complete removal above the ground surface of trees, stumps, brush, vegetation, man-made
structures, and similar debris. Grubbing shall consist of removal of stumps, roots, buried
logs and other unsuitable material and shall be performed in areas to be graded. Roots and
other projections exceeding 1½ inches in diameter shall be removed to a depth of 3 feet
below the surface of the ground. Borrow areas shall be grubbed to the extent necessary to
provide suitable fill materials.
4.2 Asphalt pavement material removed during clearing operations should be properly
disposed at an approved off-site facility or in an acceptable area of the project evaluated by
Geocon and the property owner. Concrete fragments that are free of reinforcing steel may
be placed in fills, provided they are placed in accordance with Section 6.2 or 6.3 of this
document.
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4.3 After clearing and grubbing of organic matter and other unsuitable material, loose or
porous soils shall be removed to the depth recommended in the Geotechnical Report. The
depth of removal and compaction should be observed and approved by a representative of
the Consultant. The exposed surface shall then be plowed or scarified to a minimum depth
of 6 inches and until the surface is free from uneven features that would tend to prevent
uniform compaction by the equipment to be used.
4.4 Where the slope ratio of the original ground is steeper than 5:1 (horizontal:vertical), or
where recommended by the Consultant, the original ground should be benched in
accordance with the following illustration.
TYPICAL BENCHING DETAIL
Remove All
Unsuitable Material
As Recommended By
Consultant
Finish Grade Original Ground
Finish Slope Surface
Slope To Be Such That
Sloughing Or Sliding
Does Not Occur Varies
“B”
See Note 1
No Scale
See Note 2
1
2
DETAIL NOTES: (1) Key width "B" should be a minimum of 10 feet, or sufficiently wide to permit
complete coverage with the compaction equipment used. The base of the key should
be graded horizontal, or inclined slightly into the natural slope.
(2) The outside of the key should be below the topsoil or unsuitable surficial material
and at least 2 feet into dense formational material. Where hard rock is exposed in the
bottom of the key, the depth and configuration of the key may be modified as
approved by the Consultant.
4.5 After areas to receive fill have been cleared and scarified, the surface should be moisture
conditioned to achieve the proper moisture content, and compacted as recommended in
Section 6 of these specifications.
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5. COMPACTION EQUIPMENT
5.1 Compaction of soil or soil-rock fill shall be accomplished by sheepsfoot or segmented-steel
wheeled rollers, vibratory rollers, multiple-wheel pneumatic-tired rollers, or other types of
acceptable compaction equipment. Equipment shall be of such a design that it will be
capable of compacting the soil or soil-rock fill to the specified relative compaction at the
specified moisture content.
5.2 Compaction of rock fills shall be performed in accordance with Section 6.3.
6. PLACING, SPREADING AND COMPACTION OF FILL MATERIAL
6.1 Soil fill, as defined in Paragraph 3.1.1, shall be placed by the Contractor in accordance with
the following recommendations:
6.1.1 Soil fill shall be placed by the Contractor in layers that, when compacted, should
generally not exceed 8 inches. Each layer shall be spread evenly and shall be
thoroughly mixed during spreading to obtain uniformity of material and moisture
in each layer. The entire fill shall be constructed as a unit in nearly level lifts. Rock
materials greater than 12 inches in maximum dimension shall be placed in
accordance with Section 6.2 or 6.3 of these specifications.
6.1.2 In general, the soil fill shall be compacted at a moisture content at or above the
optimum moisture content as determined by ASTM D 1557.
6.1.3 When the moisture content of soil fill is below that specified by the Consultant,
water shall be added by the Contractor until the moisture content is in the range
specified.
6.1.4 When the moisture content of the soil fill is above the range specified by the
Consultant or too wet to achieve proper compaction, the soil fill shall be aerated by
the Contractor by blading/mixing, or other satisfactory methods until the moisture
content is within the range specified.
6.1.5 After each layer has been placed, mixed, and spread evenly, it shall be thoroughly
compacted by the Contractor to a relative compaction of at least 90 percent.
Relative compaction is defined as the ratio (expressed in percent) of the in-place
dry density of the compacted fill to the maximum laboratory dry density as
determined in accordance with ASTM D 1557. Compaction shall be continuous
over the entire area, and compaction equipment shall make sufficient passes so that
the specified minimum relative compaction has been achieved throughout the
entire fill.
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6.1.6 Where practical, soils having an Expansion Index greater than 50 should be placed
at least 3 feet below finish pad grade and should be compacted at a moisture
content generally 2 to 4 percent greater than the optimum moisture content for the
material.
6.1.7 Properly compacted soil fill shall extend to the design surface of fill slopes. To
achieve proper compaction, it is recommended that fill sl opes be over-built by at
least 3 feet and then cut to the design grade. This procedure is considered
preferable to track-walking of slopes, as described in the following paragraph.
6.1.8 As an alternative to over-building of slopes, slope faces may be back-rolled with a
heavy-duty loaded sheepsfoot or vibratory roller at maximum 4-foot fill height
intervals. Upon completion, slopes should then be track-walked with a D-8 dozer
or similar equipment, such that a dozer track covers all slope surfaces at least
twice.
6.2 Soil-rock fill, as defined in Paragraph 3.1.2, shall be placed by the Contractor in accordance
with the following recommendations:
6.2.1 Rocks larger than 12 inches but less than 4 feet in maximum dimension may be
incorporated into the compacted soil fill, but shall be limited to the area measured
15 feet minimum horizontally from the slope face and 5 feet below finish grade or
3 feet below the deepest utility, whichever is deeper.
6.2.2 Rocks or rock fragments up to 4 feet in maximum dimension may either be
individually placed or placed in windrows. Under certain conditions, rocks or rock
fragments up to 10 feet in maximum dimension may be placed using similar
methods. The acceptability of placing rock materials greater than 4 feet in
maximum dimension shall be evaluated during grading as specific cases arise and
shall be approved by the Consultant prior to placement.
6.2.3 For individual placement, sufficient space shall be provided between rocks to allow
for passage of compaction equipment.
6.2.4 For windrow placement, the rocks should be placed in trenches excavated in
properly compacted soil fill. Trenches should be approximately 5 feet wide and
4 feet deep in maximum dimension. The voids around and beneath rocks should be
filled with approved granular soil having a Sand Equivalent of 30 or greater and
should be compacted by flooding. Windrows may also be placed utilizing an
"open-face" method in lieu of the trench procedure, however, this method should
first be approved by the Consultant.
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6.2.5 Windrows should generally be parallel to each other and may be placed either
parallel to or perpendicular to the face of the slope depending on the site geometry.
The minimum horizontal spacing for windrows shall be 12 feet center-to-center
with a 5-foot stagger or offset from lower courses to next overlying course. The
minimum vertical spacing between windrow courses shall be 2 feet from the top of
a lower windrow to the bottom of the next higher windrow.
6.2.6 Rock placement, fill placement and flooding of approved granular soil in the
windrows should be continuously observed by the Consultant.
6.3 Rock fills, as defined in Section 3.1.3, shall be placed by the Contractor in accordance with
the following recommendations:
6.3.1 The base of the rock fill shall be placed on a sloping surface (minimum slope of 2
percent). The surface shall slope toward suitable subdrainage outlet facilities. The
rock fills shall be provided with subdrains during construction so that a hydrostatic
pressure buildup does not develop. The subdrains shall be permanently connected
to controlled drainage facilities to control post-construction infiltration of water.
6.3.2 Rock fills shall be placed in lifts not exceeding 3 feet. Placement shall be by rock
trucks traversing previously placed lifts and dumping at the edge of the currently
placed lift. Spreading of the rock fill shall be by dozer to facilitate seating of the
rock. The rock fill shall be watered heavily during placement. Watering shall
consist of water trucks traversing in front of the current rock lift face and spraying
water continuously during rock placement. Compaction equipment with
compactive energy comparable to or greater than that of a 20-ton steel vibratory
roller or other compaction equipment providing suitable energy to achieve the
required compaction or deflection as recommended in Paragraph 6.3.3 shall be
utilized. The number of passes to be made should be determined as described in
Paragraph 6.3.3. Once a rock fill lift has been covered with soil fill, no additional
rock fill lifts will be permitted over the soil fill.
6.3.3 Plate bearing tests, in accordance with ASTM D 1196, may be performed in both
the compacted soil fill and in the rock fill to aid in determining the required
minimum number of passes of the compaction equipment. If performed, a
minimum of three plate bearing tests should be performed in the properly
compacted soil fill (minimum relative compaction of 90 percent). Plate bearing
tests shall then be performed on areas of rock fill having two passes, four passes
and six passes of the compaction equipment, respectively. The number of passes
required for the rock fill shall be determined by comparing the results of the plate
bearing tests for the soil fill and the rock fill and by evaluating the deflection
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variation with number of passes. The required number of passes of the compaction
equipment will be performed as necessary until the plate bearing deflections are
equal to or less than that determined for the properly compacted soil fill. In no case
will the required number of passes be less than two.
6.3.4 A representative of the Consultant should be present during rock fill operations to
observe that the minimum number of “passes” have been obtained, that water is
being properly applied and that specified procedures are being followed. The actual
number of plate bearing tests will be determined by the Consultant during grading.
6.3.5 Test pits shall be excavated by the Contractor so that the Consultant can state that,
in their opinion, sufficient water is present and that voids between large rocks are
properly filled with smaller rock material. In-place density testing will not be
required in the rock fills.
6.3.6 To reduce the potential for “piping” of fines into the rock fill from overlying soil
fill material, a 2-foot layer of graded filter material shall be placed above the
uppermost lift of rock fill. The need to place graded filter material below the rock
should be determined by the Consultant prior to commencing grading. The
gradation of the graded filter material will be determined at the time the rock fill is
being excavated. Materials typical of the rock fill should be submitted to the
Consultant in a timely manner, to allow design of the graded filter prior to the
commencement of rock fill placement.
6.3.7 Rock fill placement should be continuously observed during placement by the
Consultant.
7. SUBDRAINS
7.1 The geologic units on the site may have permeability characteristics and/or fracture
systems that could be susceptible under certain conditions to seepage. The use of canyon
subdrains may be necessary to mitigate the potential for adverse impacts associated with
seepage conditions. Canyon subdrains with lengths in excess of 500 feet or extensions of
existing offsite subdrains should use 8-inch-diameter pipes. Canyon subdrains less than 500
feet in length should use 6-inch-diameter pipes.
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TYPICAL CANYON DRAIN DETAIL
7.2 Slope drains within stability fill keyways should use 4-inch-diameter (or lager) pipes.
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TYPICAL STABILITY FILL DETAIL
7.3 The actual subdrain locations will be evaluated in the field during the remedial grading
operations. Additional drains may be necessary depending on the conditions observed and
the requirements of the local regulatory agencies. Appropriate subdrain outlets should be
evaluated prior to finalizing 40-scale grading plans.
7.4 Rock fill or soil-rock fill areas may require subdrains along their down-slope perimeters to
mitigate the potential for buildup of water from construction or landscape irrigation. The
subdrains should be at least 6-inch-diameter pipes encapsulated in gravel and filter fabric.
Rock fill drains should be constructed using the same requirements as canyon subdrains.
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7.5 Prior to outletting, the final 20-foot segment of a subdrain that will not be extended during
future development should consist of non-perforated drainpipe. At the non-perforated/
perforated interface, a seepage cutoff wall should be constructed on the downslope side of
the pipe.
TYPICAL CUT OFF WALL DETAIL
7.6 Subdrains that discharge into a natural drainage course or open space area should be
provided with a permanent headwall structure.
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TYPICAL HEADWALL DETAIL
7.7 The final grading plans should show the location of the proposed subdrains. After
completion of remedial excavations and subdrain installation, the project civil engineer
should survey the drain locations and prepare an “as-built” map showing the drain
locations. The final outlet and connection locations should be determined during grading
operations. Subdrains that will be extended on adjacent projects after grading can be placed
on formational material and a vertical riser should be placed at the end of the subdrain. The
grading contractor should consider videoing the subdrains shortly after burial to check
proper installation and functionality. The contractor is responsible for the performance of
the drains.
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8. OBSERVATION AND TESTING
8.1 The Consultant shall be the Owner’s representative to observe and perform tests during
clearing, grubbing, filling, and compaction operations. In general, no more than 2 feet in
vertical elevation of soil or soil-rock fill should be placed without at least one field density
test being performed within that interval. In addition, a minimum of one field density test
should be performed for every 2,000 cubic yards of soil or soil-rock fill placed and
compacted.
8.2 The Consultant should perform a sufficient distribution of field density tests of the
compacted soil or soil-rock fill to provide a basis for expressing an opinion whether the fill
material is compacted as specified. Density tests shall be performed in the compacted
materials below any disturbed surface. When these tests indicate that the density of any
layer of fill or portion thereof is below that specified, the particular layer or areas
represented by the test shall be reworked until the specified density has been achieved.
8.3 During placement of rock fill, the Consultant should observe that the minimum number of
passes have been obtained per the criteria discussed in Section 6.3.3. The Consultant
should request the excavation of observation pits and may perform plate bearing tests on
the placed rock fills. The observation pits will be excavated to provide a basis for
expressing an opinion as to whether the rock fill is properly seated and sufficient moisture
has been applied to the material. When observations indicate that a layer of rock fill or any
portion thereof is below that specified, the affected layer or area shall be reworked until the
rock fill has been adequately seated and sufficient moisture applied.
8.4 A settlement monitoring program designed by the Consultant may be conducted in areas of
rock fill placement. The specific design of the monitoring program shall be as
recommended in the Conclusions and Recommendations section of the project
Geotechnical Report or in the final report of testing and observation services performed
during grading.
8.5 We should observe the placement of subdrains, to check that the drainage devices have
been placed and constructed in substantial conformance with project specifications.
8.6 Testing procedures shall conform to the following Standards as appropriate:
8.6.1 Soil and Soil-Rock Fills:
8.6.1.1 Field Density Test, ASTM D 1556, Density of Soil In-Place By the
Sand-Cone Method.
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8.6.1.2 Field Density Test, Nuclear Method, ASTM D 6938, Density of Soil and
Soil-Aggregate In-Place by Nuclear Methods (Shallow Depth).
8.6.1.3 Laboratory Compaction Test, ASTM D 1557, Moisture-Density
Relations of Soils and Soil-Aggregate Mixtures Using 10-Pound
Hammer and 18-Inch Drop.
8.6.1.4. Expansion Index Test, ASTM D 4829, Expansion Index Test.
9. PROTECTION OF WORK
9.1 During construction, the Contractor shall properly grade all excavated surfaces to provide
positive drainage and prevent ponding of water. Drainage of surface water shall be
controlled to avoid damage to adjoining properties or to finished work on the site. The
Contractor shall take remedial measures to prevent erosion of freshly graded areas until
such time as permanent drainage and erosion control features have been installed. Areas
subjected to erosion or sedimentation shall be properly prepared in accordance with the
Specifications prior to placing additional fill or structures.
9.2 After completion of grading as observed and tested by the Consultant, no further
excavation or filling shall be conducted except in conjunction with the services of the
Consultant.
10. CERTIFICATIONS AND FINAL REPORTS
10.1 Upon completion of the work, Contractor shall furnish Owner a certification by the Civil
Engineer stating that the lots and/or building pads are graded to within 0.1 foot vertically of
elevations shown on the grading plan and that all tops and toes of slopes are within 0.5 foot
horizontally of the positions shown on the grading plans. After installation of a section of
subdrain, the project Civil Engineer should survey its location and prepare an as-built plan
of the subdrain location. The project Civil Engineer should verify the proper outlet for the
subdrains and the Contractor should ensure that the drain system is free of obstructions.
10.2 The Owner is responsible for furnishing a final as-graded soil and geologic report
satisfactory to the appropriate governing or accepting agencies. The as-graded report
should be prepared and signed by a California licensed Civil Engineer experienced in
geotechnical engineering and by a California Certified Engineering Geologist, indicating
that the geotechnical aspects of the grading were performed in substantial conformance
with the Specifications or approved changes to the Specifications.
Geocon Project No. G1006-52-05 September 30, 2022
Revised May 5, 2023
LIST OF REFERENCES
1.2019 California Building Code, California Code of Regulations, Title 24, Part 2, based on the 2018 International Building Code, prepared by California Building Standards Commission, dated July 2019.
2.ACI 318-14, Building Code Requirements for Structural Concrete and Commentary on Building Code Requirements for Structural Concrete, prepared by the American Concrete Institute, dated September 2014.
3.American Concrete Institute, ACI 318-11, Building Code Requirements for Structural
Concrete and Commentary, dated August, 2011.
4.ASCE 7-16, Minimum Design Loads and Associated Criteria for Buildings and Other Structures, 2017.
5.California Geologic Survey (CGS), Geologic Map of the Jamul Mountains 7.5′ Quadrangle, San Diego County, California: A Digital Database, scale 1:24,000, 2002.
6.California Geologic Survey, Seismic Shaking Hazards in California, Based on the USGS/CGS Probabilistic Seismic Hazards Assessment (PSHA) Model, 2002 (revised April 2003). 10% probability of being exceeded in 50 years. http://redirect.conservation.ca.gov/cgs/rghm/pshamap/pshamain.html
7.Geocon Incorporated, Geotechnical Investigation, Otay Ranch Village 4, Chula Vista, California, prepared by Geocon Incorporated, dated July 19, 2019 (Project No. G1806-11-02).
8.Geocon Incorporated, Update Geotechnical Investigation, Otay Ranch Village 3 North, and Village 4 Park Site, 40-Scale Grading Plan Submittal, Chula Vista, California, prepared by Geocon Incorporated, dated April 21, 2016 (Project No. 06930-52-05).
9.Geotechnics, Incorporated, Interim As-Graded Report, High School 13 Portion of McMillin Otay Ranch, Village 7, Chula Vista, California, May 11, 2005.
10.Geology and Mineral Resources of San Diego County, California, California Division of
11.Todd, Victoria R., Preliminary Geologic Map of the El Cajon 30’ x 60’ Quadrangle, Southern California, USGS, Open File Report 2004-1361, Scale 1:100,000, 2004.
12.Structural Engineers Association of California (SEAOC) and Office of Statewide Health Planning and Development (OSHPD), Seismic Design Maps, https://seismicmaps.org/, accessed January 11, 2019.
13.United States Geological Survey, 2002 Interactive Deaggregations, http://eqint.cr.usgs.gov/deaggint/2002/index.php
14.Unpublished Geotechnical Reports and Information, Geocon Incorporated.
15.USGS computer program, Seismic Hazard Curves and Uniform Hazard Response Spectra, http://earthquake.usgs.gov/research/hazmaps/design/
16.Walsh, Stephen L., and Demere, Thomas A., 1991, Age and Stratigraphy of the Sweetwater and Otay Formations, San Diego County California, In Abbott, P. L. and May, J. A., eds., 1991, Eocene Geologic history San Diego Region, Pacific section SEPM, Vol. 68, p. 131-148.