HomeMy WebLinkAboutAppendix F - Geology and Soils
APPENDIX F
Geotechnical Investigation,Results of Infiltration Testing, and
Paleontological
Resource Assessment
GEOTECHNICAL INVESTIGATION
PROPOSED WAREHOUSE
NEC Sierra Avenue and Clubhouse Drive
Fontana, California
for
Seefried Industrial Properties, Inc.
22885 Savi Ranch Parkway Suite E Yorba Linda California 92887
voice: (714) 685-1115 fax: (714) 685-1118 www.socalgeo.com
February 5, 2021
Seefried Industrial Properties, Inc.
2321 Rosecrans Avenue, Suite 2220
El Segundo, California 90245
Attention: Mr. Scott Irwin
Senior Vice President – Southern California
Project No.: 20G250-1
Subject: Geotechnical Investigation
Proposed Warehouse
NEC Sierra Avenue and Clubhouse Drive
Fontana, California
Dear Mr. Irwin:
In accordance with your request, we have conducted a geotechnical investigation at the subject
site. We are pleased to present this report summarizing the conclusions and recommendations
developed from our investigation.
We sincerely appreciate the opportunity to be of service on this project. We look forward to
providing additional consulting services during the course of the project. If we may be of further
assistance in any manner, please contact our office.
Respectfully Submitted,
SOUTHERN CALIFORNIA GEOTECHNICAL, INC.
Joseph Lozano Leon
Staff Engineer
Robert G. Trazo, GE 2655
Principal Engineer
Distribution: (1) Addressee
Proposed Warehouse – Fontana, CA
Project No. 20G250-1
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TABLE OF CONTENTS
1.0 EXECUTIVE SUMMARY 2
2.0 SCOPE OF SERVICES 5
3.0 SITE AND PROJECT DESCRIPTION 6
3.1 Site Conditions 6
3.2 Proposed Development 6
4.0 SUBSURFACE EXPLORATION 8
4.1 Scope of Exploration/Sampling Methods 8
4.2 Geotechnical Conditions 8
5.0 LABORATORY TESTING 10
6.0 CONCLUSIONS AND RECOMMENDATIONS 12
6.1 Seismic Design Considerations 12
6.2 Geotechnical Design Considerations 14
6.3 Site Grading Recommendations 16
6.4 Construction Considerations 20
6.5 Foundation Design and Construction 20
6.6 Floor Slab Design and Construction 22
6.7 Retaining Wall Design and Construction 23
6.8 Pavement Design Parameters 25
7.0 GENERAL COMMENTS 28
APPENDICES
A Plate 1: Site Location Map
Plate 2: Boring and Trench Location Plan
B Boring and Trench Logs
C Laboratory Test Results
D Grading Guide Specifications
E Seismic Design Parameters
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Project No. 20G250-1
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1.0 EXECUTIVE SUMMARY
Presented below is a brief summary of the conclusions and recommendations of this investigation.
Since this summary is not all inclusive, it should be read in complete context with the entire
report.
Geotechnical Design Considerations
• Artificial fill soils were encountered at some of the boring locations, extending from the ground
surface to depths of 1 to 3± feet.
• The fill soils possess varying strengths. The existing fill soils are considered to represent
undocumented fill. These soils, in their present condition, are not considered suitable for
support of the foundation loads of the new structure. Additionally, it is anticipated that
demolition of the existing structures and associated improvements will cause disturbance of
the upper 4± feet of soil.
• Remedial grading will be necessary to remove all of the undocumented fill soils in their
entirety, the upper portion of the near-surface native alluvial soils, and any soils disturbed
during the demolition process, and replace these materials as compacted structural fill soils.
Site Preparation Recommendations
• Demolition of any subsurface improvements that will not remain in place will be necessary in
order to facilitate the construction of the proposed development. Debris resultant from
demolition should be disposed of off-site in accordance with local regulations. Alternatively,
concrete and asphalt debris may be pulverized to a maximum 2-inch particle size, well mixed
with the on-site soils, and incorporated into new structural fills or it may be crushed and made
into crushed miscellaneous base (CMB), if desired.
• Initial site stripping should include removal of the existing vegetation including grass and
weeds, as well as any underlying topsoil, and any trees that will not remain with the proposed
development. Stripping should also include the removal of any tree root masses. These
materials should be disposed of off-site.
• Remedial grading is recommended to be performed within the proposed building area in order
to remove all of the undocumented fill soils in their entirety, the upper portion of the near-
surface native alluvial soils, and any soils disturbed during the demolition process. The soils
within the proposed building area should be overexcavated to a depth of 3 feet below existing
grade and to a depth of at least 3 feet below proposed building pad subgrade elevations.
• The depth of overexcavation should also be sufficient to remove any existing undocumented
fill soils. The proposed foundation influence zones should be overexcavated to a depth of at
least 2 feet below proposed foundation bearing grade.
• Following completion of the overexcavation, the exposed soils should be scarified to a depth
of at least 12 inches, and thoroughly flooded to raise the moisture content of the underlying
soils to at least 0 to 4 percent above optimum moisture content, extending to a depth of at
least 24 inches. The overexcavation subgrade soils should then be recompacted to at least 90
percent of the ASTM D-1557 maximum dry density. The previously excavated soils may then
be replaced as compacted structural fill.
• The on-site soils contain significant amounts of oversized materials, including cobbles and
occasional boulders. Where grading will require excavation into these materials, selective
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Project No. 20G250-1
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grading techniques will be required to remove the cobbles and/or boulders from these soils
prior to reuse as fill.
• The presence of particles greater than 3 inches in diameter within the upper 1 to 3 feet of
the building pad subgrade will impact the utility and foundation excavations. Depending on
the depths of fills required within the proposed parking areas, it may be feasible to sort the
on-site soils, placing the materials greater than 3 inches in diameter within the lower depths
of the fills, and limiting the upper 1 to 3 feet of soils to materials less than 3 inches in size.
Oversized materials could also be placed within the lower depths of the recommended
overexcavations. In order to achieve this grading, it would likely be necessary to use rock
buckets and/or rock sieves to separate the oversized materials from the remaining soil.
Although such selective grading will facilitate further construction activities, it is not
considered mandatory and a suitable subgrade could be achieved without such extensive
sorting. However, in any case, it is recommended that all materials greater than 6 inches in
size be excluded from the upper 1 foot of the surface of any compacted fills.
• The new pavement and flatwork subgrade soils are recommended to be scarified to a depth
of 12± inches, thoroughly moisture conditioned and recompacted to at least 90 percent of
the ASTM D-1557 maximum dry density.
Foundation Design Recommendations
• Conventional shallow foundations, supported in newly placed compacted fill.
• 2,500 lbs/ft2 maximum allowable soil bearing pressure.
• Reinforcement consisting of at least two (2) No. 5 rebars (1 top and 1 bottom) in strip footings.
Additional reinforcement may be necessary for structural considerations.
Building Floor Slab Design Recommendations
• Conventional Slab-on-Grade: minimum 5 inches thick.
• Modulus of Subgrade Reaction: k = 150 psi/in.
• Reinforcement is not expected to be necessary for geotechnical considerations. The actual
thickness and reinforcement of the floor slab should be determined by the structural engineer.
Pavement Design Recommendations
ASPHALT PAVEMENTS (R = 50)
Materials
Thickness (inches)
Parking
Stalls
(TI = 4.0)
Auto Drive
Lanes
(TI = 5.0)
Truck Traffic
(TI = 6.0) (TI = 7.0) (TI = 8.0)
Asphalt Concrete 3 3 3½ 4 5
Aggregate Base 3 3 4 5 5
Compacted Subgrade
(90% minimum compaction) 12 12 12 12 12
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PORTLAND CEMENT CONCRETE PAVEMENTS (R = 50)
Materials
Thickness (inches)
Automobile
Parking and
Drive Areas
(TI = 5.0)
Truck Traffic
(TI =6.0) (TI =7.0) (TI =8.0)
PCC 5 5 5½ 6½
Compacted Subgrade
(95% minimum compaction) 12 12 12 12
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Project No. 20G250-1
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2.0 SCOPE OF SERVICES
The scope of services performed for this project was in general accordance with our Proposal No.
20P444, dated December 16, 2020. The scope of services included a visual site reconnaissance,
subsurface exploration, field and laboratory testing, and geotechnical engineering analysis to
provide criteria for preparing the design of the building foundations, building floor slab, and
parking lot pavements along with site preparation recommendations and construction
considerations for the proposed development. The evaluation of the environmental aspects of
this site was beyond the scope of services for this geotechnical investigation.
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3.0 SITE AND PROJECT DESCRIPTION
3.1 Site Conditions
The subject site is located at the northeast corner of Sierra Avenue and Clubhouse Drive in
Fontana, California. The site is bounded to the north and south by existing commercial/industrial
buildings, to the west by Sierra Avenue, and to the east by Mango Avenue. The general location
of the site is illustrated on the Site Location Map, enclosed as Plate 1 in Appendix A of this report.
The site consists of a rectangular-shaped property, 18.44± acres in size. The overall site is
presently developed with four (4) commercial/industrial buildings ranging from 5,000 to 25,000±
ft² in size. The northwestern quadrant is developed with one building and is utilized as a wooden
pallet facility. The northeastern quadrant is developed with one building and is utilized as a
carnival attraction repair facility with truck trailer parking. The southwestern quadrant is
developed with one building and open-graded gravel pavements and is utilized for truck trailer
storage. The southeastern quadrant is developed with one building and is utilized as a storage
facility. The existing buildings are single-story metal-framed structures and are assumed to be
supported on conventional shallow foundations with concrete slab-on-grade floors. Ground
surface cover consists mainly of open graded gravel and exposed soil, with asphaltic concrete
(AC) or Portland cement concrete (PCC) pavements surrounding the buildings. Little to no
vegetation was encountered throughout the overall site. Few large trees are present between the
northwest and northeast quadrants.
Topographic information was obtained from a conceptual site plan prepared by Huitt-Zollars, Inc.
Based on our review of this plan, the existing site topography generally slopes downward to the
south at a gradient of 3± percent. The elevation at the subject site ranges from 1630± feet mean
sea level (msl) in the northern region of the site to 1612± feet msl in the southern region.
3.2 Proposed Development
Based on the conceptual plan provided to our office by the client, the subject site will be developed
with a 389,140± ft² warehouse, located in the north-central region of the site. Dock-high doors
will be constructed along a portion of the south building wall. The proposed building is expected
to be surrounded by AC pavements in the parking and drive areas, PCC pavements in the loading
dock area, and concrete flatwork and landscaped planters throughout the site.
Detailed structural information has not been provided. It is assumed that the new building will be
a single-story structure of tilt-up concrete construction, typically supported on conventional
shallow foundations with a concrete slab-on-grade floor. Based on the assumed construction,
maximum column and wall loads are expected to be on the order of 100 kips and 4 to 6 kips per
linear foot, respectively.
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No significant amounts of below-grade construction, such as basements or crawl spaces, are
expected to be included in the proposed development. Based on the assumed topography, cuts
and fills of 3 to 5± feet are expected to be necessary to achieve the proposed site grades.
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Project No. 20G250-1
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4.0 SUBSURFACE EXPLORATION
4.1 Scope of Exploration/Sampling Methods
The subsurface exploration conducted for this project consisted of six (6) borings advanced to
depths of 2½ to 15½± feet below the existing site grades and four (4) trenches excavated to
depths of 8½ to 10± feet. One of the trenches and all of the borings were terminated at depths
shallower than proposed after encountering refusal on cobbles. All of the borings and trenches
were logged during the drilling and excavation by members of our staff.
The borings were advanced with hollow-stem augers, by a truck-mounted drilling rig. The
trenches were excavated using a backhoe with a 36-inch-wide bucket. Representative bulk and
undisturbed soil samples were taken during drilling. Relatively undisturbed samples were taken
with a split barrel “California Sampler” containing a series of one inch long, 2.416± inch diameter
brass rings. This sampling method is described in ASTM Test Method D-3550. Samples were also
taken using a 1.4± inch inside diameter split spoon sampler, in general accordance with ASTM
D-1586. Both of these samplers are driven into the ground with successive blows of a 140-pound
weight falling 30 inches. The blow counts obtained during driving are recorded for further
analysis. Bulk samples were collected in plastic bags to retain their original moisture content. The
relatively undisturbed ring samples were placed in molded plastic sleeves that were then sealed
and transported to our laboratory.
The approximate locations of the borings (identified as Boring Nos. B-1 through B-6) and trenches
(identified as Trench Nos. T-1 through T-4) are indicated on the Boring and Trench Location Plan,
included as Plate 2 in Appendix A of this report. The Boring and Trench Logs, which illustrate the
conditions encountered at the boring and trench locations, as well as the results of some of the
laboratory testing, are included in Appendix B.
4.2 Geotechnical Conditions
Artificial Fill
Artificial fill soils were encountered at the ground surface at Boring Nos. B-3, B-5, and B-6, and
at all of the trench locations, extending to depths of 1 to 3± feet below existing site grades. The
fill soils consist of loose to dense silty fine to coarse sands, fine to coarse sands, and silty fine
sands. Occasional cobbles and variable gravel content were encountered throughout the artificial
fill. Boring No. B-6 was terminated within the artificial fill at a depth of 2½± feet due to very
dense materials and extensive cobble content. The fill soils possess a disturbed mottled
appearance, resulting in their classification as artificial fill.
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Alluvium
Native alluvium was encountered at the ground surface or below the fill soils at all of the boring
and trench locations, extending to at least the maximum depth explored of 15½± feet below
existing site grades, with the exception of Boring No. B-6. The alluvium generally consists of
medium dense to very dense fine to coarse sands and gravelly fine to coarse sands. Extensive
cobble content and variable silt content were encountered throughout the alluvial strata. In
addition, occasional boulder content was encountered in Trench Nos. T-3 and T-4 as shallow as
2½± feet from the ground surface.
Groundwater
Free water was not encountered during the drilling of any of the borings nor during the excavation
of the trenches. Based on the lack of any water within the borings and trenches, and the moisture
contents of the recovered soil samples, the static groundwater table is considered to have existed
at a depth in excess of 15½± feet at the time of the subsurface exploration.
As a part of our research, we reviewed available groundwater data in order to determine
groundwater levels for the site. Recent water level data was obtained from the California
Department of Water Resources Water Data Library website,
https://wdl.water.ca.gov/waterdatalibrary/. The nearest monitoring well on record is located
3,180± feet southeast of the site. Water level readings within this monitoring well indicate a
groundwater level of 320± feet below the ground surface in March 1994.
As part of our research, we reviewed available groundwater data in order to determine the historic
high groundwater level for the site. The primary reference used to determine the historic
groundwater depths in area of the subject site is Watermaster Support Services, Western
Municipal Water District and the San Bernardino Valley Water Conservation District Cooperative
Well Measuring Program, dated Fall 2015. A well titled Mid-Valley (Fontana) F-07 exists 1,500±
feet southeast of the site and indicates a high groundwater level of 330± feet below the ground
surface in April 2000.
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5.0 LABORATORY TESTING
The soil samples recovered from the subsurface exploration were returned to our laboratory for
further testing to determine selected physical and engineering properties of the soils. The tests
are briefly discussed below. It should be noted that the test results are specific to the actual
samples tested, and variations could be expected at other locations and depths.
Classification
All recovered soil samples were classified using the Unified Soil Classification System (USCS), in
accordance with ASTM D-2488. The field identifications were then supplemented with additional
visual classifications and/or by laboratory testing. The USCS classifications are shown on the
Boring and Trench Logs and are periodically referenced throughout this report.
Density and Moisture Content
The density has been determined for selected relatively undisturbed ring samples. These densities
were determined in general accordance with the method presented in ASTM D-2937. The results
are recorded as dry unit weight in pounds per cubic foot. The moisture contents are determined
in accordance with ASTM D-2216, and are expressed as a percentage of the dry weight. These
test results are presented on the Boring and Trench Logs.
Consolidation
Selected soil samples were tested to determine their consolidation potential, in accordance with
ASTM D-2435. The testing apparatus is designed to accept either natural or remolded samples in
a one-inch high ring, approximately 2.416 inches in diameter. Each sample is then loaded
incrementally in a geometric progression and the resulting deflection is recorded at selected time
intervals. Porous stones are in contact with the top and bottom of the sample to permit the
addition or release of pore water. The samples are typically inundated with water at an
intermediate load to determine their potential for collapse or heave. The results of the
consolidation testing are plotted on Plates C-1 and C-2 in Appendix C of this report.
Maximum Dry Density and Optimum Moisture Content
A representative bulk sample has been tested for its maximum dry density and optimum moisture
content. The results have been obtained using the Modified Proctor procedure, per ASTM D-1557
and are presented on Plate C-3 in Appendix C of this report. This test is generally used to compare
the in-situ densities of undisturbed field samples, and for later compaction testing. Additional
testing of other soil types or soil mixes may be necessary at a later date.
Soluble Sulfates
A representative sample of the near-surface soil was submitted to a subcontracted analytical
laboratory for determination of soluble sulfate content. Soluble sulfates are naturally present in
soils, and if the concentration is high enough, can result in degradation of concrete which comes
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Project No. 20G250-1
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into contact with these soils. The results of the soluble sulfate testing are presented below, and
are discussed further in a subsequent section of this report.
Sample Identification Soluble Sulfates (%) Sulfate Classification
T-1 @ 0 to 5 feet 0.014 Not Applicable (S0)
Corrosivity Testing
One representative bulk sample of the near-surface soils was submitted to a subcontracted
corrosion engineering laboratory to identify potentially corrosive characteristics with respect to
common construction materials. The corrosivity testing included a determination of the electrical
resistivity, pH, and chloride and nitrate concentrations of the soils, as well as other tests. The
results of some of these tests are presented below.
Sample Identification Saturated Resistivity
(ohm-cm) pH Chlorides
(mg/kg)
Nitrates
(mg/kg)
T-1 @ 0 to 5 feet 3,800 7.5 12 87
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6.0 CONCLUSIONS AND RECOMMENDATIONS
Based on the results of our review, field exploration, laboratory testing and geotechnical analysis,
the proposed development is considered feasible from a geotechnical standpoint. The
recommendations contained in this report should be taken into the design, construction, and
grading considerations.
The recommendations are contingent upon all grading and foundation construction activities
being monitored by the geotechnical engineer of record. The recommendations are provided with
the assumption that an adequate program of client consultation, construction monitoring, and
testing will be performed during the final design and construction phases to verify compliance
with these recommendations. Maintaining Southern California Geotechnical, Inc., (SCG) as the
geotechnical consultant from the beginning to the end of the project will provide continuity of
services. The geotechnical engineering firm providing testing and observation services shall
assume the responsibility of Geotechnical Engineer of Record.
The Grading Guide Specifications, included as Appendix D, should be considered part of this
report, and should be incorporated into the project specifications. The contractor and/or owner
of the development should bring to the attention of the geotechnical engineer any conditions that
differ from those stated in this report, or which may be detrimental for the development.
6.1 Seismic Design Considerations
The subject site is located in an area which is subject to strong ground motions due to
earthquakes. The performance of a site-specific seismic hazards analysis was beyond the scope
of this investigation. However, numerous faults capable of producing significant ground motions
are located near the subject site. Due to economic considerations, it is not generally considered
reasonable to design a structure that is not susceptible to earthquake damage. Therefore,
significant damage to structures may be unavoidable during large earthquakes. The proposed
structure should, however, be designed to resist structural collapse and thereby provide
reasonable protection from serious injury, catastrophic property damage and loss of life.
Faulting and Seismicity
Research of available maps indicates that the subject site is not located within an Alquist-Priolo
Earthquake Fault Zone. Furthermore, SCG did not identify any evidence of faulting during the
geotechnical investigations. Therefore, the possibility of significant fault rupture on the site is
considered to be low.
The potential for other geologic hazards such as seismically induced settlement, lateral spreading,
tsunamis, inundation, seiches, flooding, and subsidence affecting the site is considered low.
Seismic Design Parameters
The 2019 California Building Code (CBC) provides procedures for earthquake resistant structural
design that include considerations for on-site soil conditions, occupancy, and the configuration of
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the structure including the structural system and height. The seismic design parameters
presented below are based on the soil profile and the proximity of known faults with respect to
the subject site.
Based on standards in place at the time of this report, the proposed development is expected to
be designed in accordance with the requirements of the 2019 edition of the California Building
Code (CBC), which was adopted on January 1, 2020.
The 2019 CBC Seismic Design Parameters have been generated using the SEAOC/OSHPD Seismic
Design Maps Tool, a web-based software application available at the website
www.seismicmaps.org. This software application calculates seismic design parameters in
accordance with several building code reference documents, including ASCE 7-16, upon which
the 2019 CBC is based. The application utilizes a database of risk-targeted maximum considered
earthquake (MCER) site accelerations at 0.01-degree intervals for each of the code documents.
The table below was created using data obtained from the application. The output generated
from this program is included as Plate E-1 in Appendix E of this report.
The 2019 CBC requires that a site-specific ground motion study be performed in accordance with
Section 11.4.8 of ASCE 7-16 for Site Class D sites with a mapped S1 value greater than 0.2.
However, Section 11.4.8 of ASCE 7-16 also indicates an exception to the requirement for a site-
specific ground motion hazard analysis for certain structures on Site Class D sites. The
commentary for Section 11 of ASCE 7-16 (Page 534 of Section C11 of ASCE 7-16) indicates that
“In general, this exception effectively limits the requirements for site-specific hazard analysis to
very tall and or flexible structures at Site Class D sites.” Based on our understanding of the
proposed development, the seismic design parameters presented below were
calculated assuming that the exception in Section 11.4.8 applies to the proposed
structure at this site. However, the structural engineer should verify that this
exception is applicable to the proposed structure. Based on the exception, the spectral
response accelerations presented below were calculated using the site coefficients (Fa and Fv)
from Tables 1613.2.3(1) and 1613.2.3(2) presented in Section 16.4.4 of the 2019 CBC.
2019 CBC SEISMIC DESIGN PARAMETERS
Parameter Value
Mapped Spectral Acceleration at 0.2 sec Period SS 2.262
Mapped Spectral Acceleration at 1.0 sec Period S1 0.741
Site Class --- D
Site Modified Spectral Acceleration at 0.2 sec Period SMS 2.262
Site Modified Spectral Acceleration at 1.0 sec Period SM1 1.260
Design Spectral Acceleration at 0.2 sec Period SDS 1.508
Design Spectral Acceleration at 1.0 sec Period SD1 0.840
It should be noted that the site coefficient Fv and the parameters SM1 and SD1 were not included
in the SEAOC/OSHPD Seismic Design Maps Tool output for the 2019 CBC. We calculated these
parameters-based on Table 1613.2.3(2) in Section 16.4.4 of the 2019 CBC using the value of S1
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obtained from the Seismic Design Maps Tool, assuming that a site-specific ground motion hazards
analysis is not required for the proposed building at this site.
Liquefaction
Liquefaction is the loss of strength in generally cohesionless, saturated soils when the pore-water
pressure induced in the soil by a seismic event becomes equal to or exceeds the overburden
pressure. The primary factors which influence the potential for liquefaction include groundwater
table elevation, soil type and grain size characteristics, relative density of the soil, initial confining
pressure, and intensity and duration of ground shaking. The depth within which the occurrence
of liquefaction may impact surface improvements is generally identified as the upper 50 feet
below the existing ground surface. Liquefaction potential is greater in saturated, loose, poorly
graded fine sands with a mean (d50) grain size in the range of 0.075 to 0.2 mm (Seed and Idriss,
1971). Clayey (cohesive) soils or soils which possess clay particles (d<0.005mm) in excess of 20
percent (Seed and Idriss, 1982) are generally not considered to be susceptible to liquefaction,
nor are those soils which are above the historic static groundwater table.
The California Geological Survey (CGS) has not yet conducted detailed seismic hazards mapping
in the area of the subject site. The general liquefaction susceptibility of the site was determined
by research of the San Bernardino County Land Use Plan, General Plan, Geologic Hazard Overlays.
Map FH21C for the Devore Quadrangle indicates that the subject site is not located within an area
of liquefaction susceptibility. Based on the mapping performed by the county of San Bernardino
and the subsurface conditions encountered at the boring locations, liquefaction is not considered
to be a design concern for this project.
6.2 Geotechnical Design Considerations
General
Some of the borings and all of the trench locations encountered artificial fill materials, extending
to depths of 1 to 3± feet below the existing site grades. Based on a lack of documentation
regarding the placement and compaction of the existing fill materials, these soils are considered
to consist of undocumented fill, and are not suitable for the support of the foundation loads of
the proposed building. The fill soils are underlain by native alluvium which possesses favorable
consolidation/collapse characteristics. Additionally, it is anticipated that demolition of the existing
structures will cause disturbance of the upper 4± feet of soil. Therefore, remedial grading is
considered warranted within the proposed building area in order to remove all of the
undocumented fill soils in their entirety and the upper portion of the near-surface native alluvial
soils, and replace these materials as compacted structural fill soils.
Settlement
The recommended remedial grading will remove the existing undocumented fill soils and a portion
of the near-surface native alluvial soils and replace these materials as compacted structural fill.
The native soils that will remain in place below the recommended depth of overexcavation will
not be subject to significant stress increases from the foundations of the new structure. Therefore,
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following completion of the recommended grading, post-construction settlements are expected
to be within tolerable limits.
Expansion
The near-surface soils consist of sands, silty sands and gravelly sands with no appreciable clay
content. These materials have been visually classified as non-expansive. Therefore, no design
considerations related to expansive soils are considered warranted for this site.
Soluble Sulfates
The result of the soluble sulfate testing indicates that the selected sample of the on-site soils
corresponds to Class S0 with respect to the American Concrete Institute (ACI) Publication 318-05
Building Code Requirements for Structural Concrete and Commentary, Section 4.3. Therefore,
specialized concrete mix designs are not considered to be necessary, with regard to sulfate
protection purposes. It is, however, recommended that additional soluble sulfate testing be
conducted at the completion of rough grading to verify the soluble sulfate concentrations of the
soils which are present at pad grade within the building area.
Corrosion Potential
The results of laboratory testing indicate that the tested sample of the on-site soils possesses a
saturated resistivity value of 3,800 ohm-cm, and a pH value of 7.5. These test results have been
evaluated in accordance with guidelines published by the Ductile Iron Pipe Research Association
(DIPRA). The DIPRA guidelines consist of a point system by which characteristics of the soils are
used to quantify the corrosivity characteristics of the site. Resistivity and pH are two of the five
factors that enter into the evaluation procedure. Redox potential, relative soil moisture content
and sulfides are also included. Although sulfide testing was not part of the scope of services for
this project, we have evaluated the corrosivity characteristics of the on-site soils using resistivity,
pH and moisture content. Based on these factors, and utilizing the DIPRA procedure, the on-site
soils are not considered to be corrosive to ductile iron pipe. Therefore, polyethylene protection is
not expected to be required for cast iron or ductile iron pipes. It should be noted that SCG does
not practice in the field of corrosion engineering. Therefore, the client may wish to contact a
corrosion engineer to provide a more thorough evaluation.
A relatively low concentration (12 mg/kg) of chlorides was detected in the sample submitted for
corrosivity testing. In general, soils possessing chloride concentrations in excess of 500 parts per
million (ppm) are considered to be corrosive with respect to steel reinforcement within reinforced
concrete. Based on the lack of any significant chlorides in the tested sample, the site is considered
to have a C1 chloride exposure in accordance with the American Concrete Institute (ACI)
Publication 318 Building Code Requirements for Structural Concrete and Commentary. Therefore,
a specialized concrete mix design for reinforced concrete for protection against chloride exposure
is not considered warranted.
Nitrates
Nitrates present in soil can be corrosive to copper tubing at concentrations greater than 50 mg/kg.
The tested sample possesses a nitrate concentration of 87 mg/kg. Based on this test result,
the on-site soils are considered to be corrosive to copper pipe. Since SCG does not
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practice in the area of corrosion engineering, we recommend that the client contact
a corrosion engineer to provide recommendations for the protection of copper
tubing/pipe in contact with the on-site soils.
Shrinkage/Subsidence
Removal and recompaction of the existing fill soils and near-surface alluvium is estimated to result
in an average shrinkage of 1 to 10 percent. However, potential shrinkage for individual samples
ranged locally between 0 and 15 percent. The potential shrinkage estimate is based on dry density
testing performed on small-diameter samples taken at the boring locations. If a more accurate
and precise shrinkage estimate is desired, SCG can perform a shrinkage study involving several
excavated test-pits where in-place densities are determined using in-situ testing methods instead
of laboratory density testing on small-diameter samples. Please contact SCG for details and a cost
estimate regarding a shrinkage study, if desired.
Minor ground subsidence is expected to occur in the soils below the zone of removal, due to
settlement and machinery working. The subsidence is estimated to be 0.1 feet.
These estimates are based on previous experience and the subsurface conditions encountered at
the boring locations. The actual amount of subsidence is expected to be variable and will be
dependent on the type of machinery used, repetitions of use, and dynamic effects, all of which
are difficult to assess precisely.
Grading and Foundation Plan Review
Grading and foundation plans were not available at the time of this report. It is therefore
recommended that we be provided with copies of the preliminary grading and foundation plans,
when they become available, for review with regard to the conclusions, recommendations, and
assumptions contained within this report.
6.3 Site Grading Recommendations
The grading recommendations presented below are based on the subsurface conditions
encountered at the boring and trench locations, and our understanding of the proposed
development. We recommend that all grading activities be completed in accordance with the
Grading Guide Specifications included as Appendix D of this report, unless superseded by site-
specific recommendations presented below.
Site Stripping and Demolition
Demolition of the existing structures, pavements, and any associated improvements will be
necessary to facilitate the construction of the proposed development. Demolition of the existing
structures should include all foundations, floor slabs, and any associated utilities. Any septic
systems encountered during demolition and/or grading (if present) should be removed in their
entirety. Any associated leach fields or other existing underground improvements should also be
removed in their entirety. Debris resultant from demolition should be disposed of off-site in
accordance with local regulations. Alternatively, concrete and asphalt debris may be pulverized
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to a maximum 2-inch particle size, well mixed with the on-site soils, and incorporated into new
structural fills or it may be crushed and made into crushed miscellaneous base (CMB), if desired.
Initial site stripping should include removal of any surficial vegetation and topsoil. This should
include any weeds, grasses, shrubs, and trees. Root systems associated with the trees should be
removed in their entirety, and the resultant excavations should be backfilled with compacted
structural fill soils. The actual extent of site stripping should be determined in the field by the
geotechnical engineer, based on the organic content and stability of the materials encountered.
Treatment of Existing Soils: Building Pad
Remedial grading should be performed within the proposed building area in order to remove the
existing undocumented fill soils, any soils disturbed during demolition, and a portion of the near-
surface native alluvium. Based on conditions encountered at the boring locations, the existing
soils within the proposed building area are recommended to be overexcavated to a depth of at
least 3 feet below existing grades and to a depth of at least 3 feet below proposed building pad
subgrade elevations, whichever is greater. The depth of the overexcavation should also extend
to a depth sufficient to remove all undocumented fill soils and soils disturbed during demolition.
Within the influence zones of the new foundations, the overexcavation should extend to a depth
of at least 2 feet below proposed foundation bearing grade.
The overexcavation areas should extend at least 5 feet beyond the building and foundation
perimeters, and to an extent equal to the depth of fill placed below the foundation bearing grade,
whichever is greater. If the proposed structure incorporates any exterior columns (such as for a
canopy or overhang) the area of overexcavation should also encompass these areas.
Following completion of the overexcavation, the subgrade soils within the overexcavation areas
should be evaluated by the geotechnical engineer to verify their suitability to serve as the
structural fill subgrade, as well as to support the foundation loads of the new structure. This
evaluation should include proofrolling and probing to identify any soft, loose or otherwise unstable
soils that must be removed. Some localized areas of deeper excavation may be required if
additional fill materials or loose, porous, or low-density native soils are encountered at the base
of the overexcavation. Materials suitable to serve as the structural fill subgrade within the building
areas should consist of native soils which possess an in-situ density equal to at least 85 percent
of the ASTM D-1557 maximum dry density.
After a suitable overexcavation subgrade has been achieved, the exposed soils should
be scarified to a depth of at least 12 inches, and thoroughly flooded to raise the
moisture content of the underlying soils to at least 0 to 4 percent above optimum
moisture content, extending to a depth of at least 24 inches. The subgrade soils should
then be recompacted to at least 90 percent of the ASTM D-1557 maximum dry density. The
building pad area may then be raised to grade with previously excavated soils or imported
structural fill.
Treatment of Existing Soils: Retaining Walls and Site Walls
The existing soils within the areas of any proposed retaining walls and site walls should be
overexcavated to a depth of 2 feet below foundation bearing grade and replaced as compacted
structural fill as discussed above for the proposed building pad. Any undocumented fill soils or
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disturbed native alluvium within any of these foundation areas should be removed in their
entirety. The overexcavation areas should extend at least 5 feet beyond the foundation
perimeters, and to an extent equal to the depth of fill below the new foundations. Any erection
pads for tilt-up concrete walls are considered to be part of the foundation system. Therefore,
these overexcavation recommendations are applicable to erection pads. The overexcavation
subgrade soils should be evaluated by the geotechnical engineer prior to scarifying, moisture
conditioning to within 0 to 4 percent above the optimum moisture content, and recompacting the
upper 12 inches of exposed subgrade soils. The previously excavated soils may then be replaced
as compacted structural fill.
If the full lateral recommended remedial grading cannot be completed for the proposed retaining
walls and site walls located along property lines, the foundations for those walls should be
designed using a reduced allowable bearing pressure. Furthermore, the contractor should take
necessary precautions to protect the adjacent improvements during rough grading. Specialized
grading techniques, such as A-B-C slot cuts, will likely be required during remedial grading. The
geotechnical engineer of record should be contacted if additional recommendations, such as
shoring design recommendations, are required during grading.
Treatment of Existing Soils: Flatwork, Parking and Drive Areas
Based on economic considerations, overexcavation of the existing near-surface existing soils in
the new flatwork, parking and drive areas is not considered warranted, with the exception of
areas where lower strength or unstable soils are identified by the geotechnical engineer during
grading. Subgrade preparation in the new flatwork, parking and drive areas should initially consist
of removal of all soils disturbed during stripping and demolition operations.
The geotechnical engineer should then evaluate the subgrade to identify any areas of additional
unsuitable soils. Any such materials should be removed to a level of firm and unyielding soil. The
exposed subgrade soils should then be scarified to a depth of 12± inches, moisture conditioned
to 0 to 4 percent above the optimum moisture content, and recompacted to at least 90 percent
of the ASTM D-1557 maximum dry density. Based on the presence of variable strength surficial
soils throughout the site, it is expected that some isolated areas of additional overexcavation may
be required to remove zones of lower strength, unsuitable soils.
The grading recommendations presented above for the proposed flatwork, parking and drive
areas assume that the owner and/or developer can tolerate minor amounts of settlement within
these areas. The grading recommendations presented above do not mitigate the extent of
undocumented fill or compressible/collapsible native alluvium in the flatwork, parking and drive
areas. As such, some settlement and associated pavement distress could occur. Typically, repair
of such distressed areas involves significantly lower costs than completely mitigating these soils
at the time of construction. If the owner cannot tolerate the risk of such settlements, the flatwork,
parking and drive areas should be overexcavated to a depth of 2 feet below proposed pavement
subgrade elevation, with the resulting soils replaced as compacted structural fill.
Fill Placement
• Fill soils should be placed in thin (6± inches), near-horizontal lifts, moisture conditioned
to 0 to 4 percent above the optimum moisture content, and compacted.
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• On-site soils may be used for fill provided they are cleaned of any debris to the satisfaction
of the geotechnical engineer.
• All grading and fill placement activities should be completed in accordance with the
requirements of the 2019 CBC and the grading code of the city of Fontana.
• All fill soils should be compacted to at least 90 percent of the ASTM D-1557 maximum dry
density.
• Compaction tests should be performed periodically by the geotechnical engineer as
random verification of compaction and moisture content. These tests are intended to aid
the contractor. Since the tests are taken at discrete locations and depths, they may not
be indicative of the entire fill and therefore should not relieve the contractor of his
responsibility to meet the job specifications.
Selective Grading and Oversized Material Placement
The native alluvial soils possess significant cobbles with occasional boulders. It is expected that
large grading equipment will be adequate to move the cobble containing soils as well as some of
the soils containing smaller boulders. However, some larger boulders (2± feet in size) are
expected to be encountered. It will likely be necessary to move such larger boulders individually,
and place them as oversized materials in accordance with the Grading Guide Specifications, in
Appendix D of this report.
Since the proposed grading will require excavation of cobble and boulder containing soils, it may
be desirable to selectively grade the proposed building pad area. The presence of particles greater
than 3 inches in diameter within the upper 1 to 3 feet of the building pad subgrade will impact
the utility and foundation excavations. Depending on the depths of fills required within the
proposed parking areas, it may be feasible to sort the on-site soils, placing the materials greater
than 3 inches in diameter within the lower depths of the fills, and limiting the upper 1 to 3 feet
of soils to materials less than 3 inches in size. Oversized materials could also be placed within the
lower depths of the recommended overexcavations. In order to achieve this grading, it would
likely be necessary to use rock buckets and/or rock sieves to separate the oversized materials
from the remaining soil. Although such selective grading will facilitate further construction
activities, it is not considered mandatory and a suitable subgrade could be achieved without such
extensive sorting. However, in any case, it is recommended that all materials greater than 6
inches in size be excluded from the upper 1 foot of the surface of any compacted fills.
The placement of any oversized materials should be performed in accordance with
the Grading Guide Specifications included in Appendix D of this report. If disposal of
oversized materials is required, rock blankets or windrows should be used and such areas should
be observed during construction and placement by a representative of the geotechnical engineer.
Imported Structural Fill
All imported structural fill should consist of very low expansive (EI < 20), well graded soils
possessing at least 10 percent fines (that portion of the sample passing the No. 200 sieve).
Additional specifications for structural fill are presented in the Grading Guide Specifications,
included as Appendix D.
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Utility Trench Backfill
In general, all utility trench backfill should be compacted to at least 90 percent of the ASTM D-
1557 maximum dry density. As an alternative, a clean sand (minimum Sand Equivalent of 30)
may be placed within trenches and compacted in place (jetting or flooding is not recommended).
Compacted trench backfill should conform to the requirements of the local grading code, and
more restrictive requirements may be indicated by the city of Fontana. All utility trench backfills
should be witnessed by the geotechnical engineer. The trench backfill soils should be compaction
tested where possible; probed and visually evaluated elsewhere.
Utility trenches which parallel a footing, and extending below a 1h:1v (horizontal to vertical) plane
projected from the outside edge of the footing should be backfilled with structural fill soils,
compacted to at least 90 percent of the ASTM D-1557 standard. Pea gravel backfill should not be
used for these trenches.
Any soils used to backfill voids around subsurface utility structures, such as manholes or vaults,
should be placed as compacted structural fill. If it is not practical to place compacted fill in these
areas, then such void spaces may be backfilled with lean concrete slurry. Uncompacted pea gravel
or sand is not recommended for backfilling these voids since these materials have a potential to
settle and thereby cause distress of pavements placed around these subterranean structures.
6.4 Construction Considerations
Excavation Considerations
The near-surface soils generally consist of gravelly sands and sandy gravel. These materials will
be subject to moderate caving within shallow excavations. Where caving does occur, flattened
excavation slopes may be sufficient to provide excavation stability. On a preliminary basis, the
inclination of temporary slopes should not exceed 2h:1v. Deeper excavations may require some
form of external stabilization such as shoring or bracing. Maintaining adequate moisture content
within the near-surface soils will improve excavation stability. All excavation activities on this site
should be conducted in accordance with Cal-OSHA regulations.
Groundwater
The static groundwater table is considered to have existed at a depth in excess of 15½± feet at
the time of the subsurface exploration. Therefore, groundwater is not expected to impact the
grading or foundation construction activities.
6.5 Foundation Design and Construction
Based on the preceding grading recommendations, it is assumed that the new building pad will
be underlain by structural fill soils used to replace existing undocumented fill soils and a portion
of the near-surface alluvial soils. These new structural fill soils are expected to extend to a depth
of at least 2 feet below proposed foundation bearing grade, underlain by 1± foot of additional
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soil that has been densified and moisture conditioned in place. Based on this subsurface profile,
the proposed structure may be supported on conventional shallow foundations.
Foundation Design Parameters
New square and rectangular footings may be designed as follows:
• Maximum, net allowable soil bearing pressure: 2,500 lbs/ft2.
• Maximum, net allowable soil bearing pressure: 1,500 lbs/ft2 if the full lateral extent of
remedial grading cannot be achieved.
• Minimum wall/column footing width: 14 inches/24 inches.
• Minimum longitudinal steel reinforcement within strip footings: Two (2) No. 5 rebars (1
top and 1 bottom).
• Minimum foundation embedment: 12 inches into suitable structural fill soils, and at least
18 inches below adjacent exterior grade. Interior column footings may be placed
immediately beneath the floor slab.
• It is recommended that the perimeter building foundations be continuous across all
exterior doorways. Any flatwork adjacent to the exterior doors should be doweled into the
perimeter foundations in a manner determined by the structural engineer.
The allowable bearing pressures presented above may be increased by 1/3 when considering
short duration wind or seismic loads. The minimum steel reinforcement recommended above is
based on geotechnical considerations; additional reinforcement may be necessary for structural
considerations. The actual design of the foundations should be determined by the structural
engineer.
Foundation Construction
The foundation subgrade soils should be evaluated at the time of overexcavation, as discussed
in Section 6.3 of this report. It is further recommended that the foundation subgrade soils be
evaluated by the geotechnical engineer immediately prior to steel or concrete placement. Soils
suitable for direct foundation support should consist of newly placed structural fill, compacted to
at least 90 percent of the ASTM D-1557 maximum dry density. Any unsuitable materials should
be removed to a depth of suitable bearing compacted structural fill or suitable native alluvium
(where reduced bearing pressures are utilized), with the resulting excavations backfilled with
compacted fill soils. As an alternative, lean concrete slurry (500 to 1,500 psi) may be used to
backfill such isolated overexcavations.
The foundation subgrade soils should also be properly moisture conditioned to 0 to 4 percent
above the Modified Proctor optimum, to a depth of at least 12 inches below bearing grade. Since
it is typically not feasible to increase the moisture content of the floor slab and
foundation subgrade soils once rough grading has been completed, care should be
taken to maintain the moisture content of the building pad subgrade soils throughout
the construction process.
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Estimated Foundation Settlements
Post-construction total and differential settlements of shallow foundations designed and
constructed in accordance with the previously presented recommendations are estimated to be
less than 1.0 and 0.5 inches, respectively. Differential movements are expected to occur over a
30-foot span, thereby resulting in an angular distortion of less than 0.002 inches per inch.
Lateral Load Resistance
Lateral load resistance will be developed by a combination of friction acting at the base of
foundations and slab and the passive earth pressure developed by footings below grade. The
following friction and passive pressure may be used to resist lateral forces:
• Passive Earth Pressure: 300 lbs/ft3
• Friction Coefficient: 0.30
These are allowable values, and include a factor of safety. When combining friction and passive
resistance, the passive pressure component should be reduced by one-third. These values assume
that footings will be poured directly against compacted structural fill soils. The maximum allowable
passive pressure is 3,000 lbs/ft2.
6.6 Floor Slab Design and Construction
Subgrades which will support the new floor slab should be prepared in accordance with the
recommendations contained in the Site Grading Recommendations section of this report.
Based on the anticipated grading which will occur at this site, the floor of the proposed structure
may be constructed as a conventional slab-on-grade supported on newly placed structural fill (or
densified existing soils), extending to a depth of at least 3 feet below finished pad grades. Based
on geotechnical considerations, the floor slab may be designed as follows:
• Minimum slab thickness: 5 inches.
• Modulus of Subgrade Reaction: k = 150 psi/in.
• Minimum slab reinforcement: Reinforcement is not considered necessary from a
geotechnical standpoint. The actual floor slab reinforcement should be determined by the
structural engineer, based on the imposed slab loading.
• Slab underlayment: If moisture sensitive floor coverings will be used then minimum slab
underlayment should consist of a moisture vapor barrier constructed below the entire area
of the proposed slab where such moisture sensitive floor coverings are anticipated. The
moisture vapor barrier should meet or exceed the Class A rating as defined by ASTM E
1745-97 and have a permeance rating less than 0.01 perms as described in ASTM E 96-
95 and ASTM E 154-88. A polyolefin material such as Stego® Wrap Vapor Barrier or
equivalent will meet these specifications. The moisture vapor barrier should be properly
constructed in accordance with all applicable manufacturer specifications. Given that a
rock free subgrade is anticipated and that a capillary break is not required, sand below
the barrier is not required. The need for sand and/or the amount of sand above the
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moisture vapor barrier should be specified by the structural engineer or concrete
contractor. The selection of sand above the barrier is not a geotechnical engineering issue
and hence outside our purview. Where moisture sensitive floor coverings are not
anticipated, the vapor barrier may be eliminated.
• Moisture condition the floor slab subgrade soils to 0 to 4 percent above the Modified
Proctor optimum moisture content, to a depth of 12 inches. The moisture content of the
floor slab subgrade soils should be verified by the geotechnical engineer within 24 hours
prior to concrete placement.
• Proper concrete curing techniques should be utilized to reduce the potential for slab
curling or the formation of excessive shrinkage cracks.
The actual design of the floor slab should be completed by the structural engineer to verify
adequate thickness and reinforcement.
6.7 Retaining Wall Design and Construction
Although not indicated on the site plans, some small (less than 6 feet in height) retaining walls
may be required to facilitate the new site grades. The parameters recommended for use in the
design of these walls are presented below.
Retaining Wall Design Parameters
Based on the soil conditions encountered at the trench locations, the following parameters may
be used in the design of new retaining walls for this site. The following parameters assume that
only the on-site soils will be utilized for retaining wall backfill. The near-surface soils generally
consist of sands, silty sands and gravelly sands. Based on their classification, these materials are
expected to possess a friction angle of at least 32 degrees when compacted to at least 90 percent
of the ASTM D-1557 maximum dry density.
If desired, SCG could provide design parameters for an alternative select backfill material behind
the retaining walls. The use of select backfill material could result in lower lateral earth pressures.
In order to use the design parameters for the imported select fill, this material must be placed
within the entire active failure wedge. This wedge is defined as extending from the heel of the
retaining wall upwards at an angle of approximately 60° from horizontal. If select backfill material
behind the retaining wall is desired, SCG should be contacted for supplementary
recommendations.
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RETAINING WALL DESIGN PARAMETERS
Design Parameter
Soil Type
On-site Sands
Internal Friction Angle () 32
Unit Weight 140 lbs/ft3
Equivalent
Fluid Pressure:
Active Condition
(level backfill) 43 lbs/ft3
Active Condition
(2h:1v backfill) 66 lbs/ft3
At-Rest Condition
(level backfill) 66 lbs/ft3
The walls should be designed using a soil-footing coefficient of friction of 0.30 and an equivalent
passive pressure of 300 lbs/ft3. The structural engineer should incorporate appropriate factors of
safety in the design of the retaining walls.
The active earth pressure may be used for the design of retaining walls that do not directly
support structures or support soils that in turn support structures and which will be allowed to
deflect. The at-rest earth pressure should be used for walls that will not be allowed to deflect
such as those which will support foundation bearing soils, or which will support foundation loads
directly.
Where the soils on the toe side of the retaining wall are not covered by a "hard" surface such as
a structure or pavement, the upper 1 foot of soil should be neglected when calculating passive
resistance due to the potential for the material to become disturbed or degraded during the life
of the structure.
Seismic Lateral Earth Pressures
In accordance with the 2019 CBC, any retaining walls more than 6 feet in height must be designed
for seismic lateral earth pressures. If walls 6 feet or more are required for this site, the
geotechnical engineer should be contacted for supplementary seismic lateral earth pressure
recommendations.
Retaining Wall Foundation Design
The retaining wall foundations should be underlain by at least 2 feet of newly placed structural
fill. Foundations to support new retaining walls should be designed in accordance with the general
Foundation Design Parameters presented in a previous section of this report.
Backfill Material
On-site soils may be used to backfill the retaining walls. However, all backfill material placed
within 3 feet of the back wall face should have a particle size no greater than 3 inches.
Some sorting and/or crushing operations may be required. The retaining wall backfill materials
should be well graded.
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It is recommended that a properly installed prefabricated drainage composite such as the
MiraDRAIN 6000XL (or approved equivalent), which is specifically designed for use behind
retaining walls be used. If the drainage composite material is not covered by an impermeable
surface, such as a structure or pavement, a 12-inch thick layer of a low permeability soil should
be placed over the backfill to reduce surface water migration to the underlying soils. The drainage
composite should be separated from the backfill soils by a suitable geotextile, approved by the
geotechnical engineer.
All retaining wall backfill should be placed and compacted under engineering controlled conditions
in the necessary layer thicknesses to ensure an in-place density between 90 and 93 percent of
the maximum dry density as determined by the Modified Proctor test (ASTM D1557). Care should
be taken to avoid over-compaction of the soils behind the retaining walls, and the use of heavy
compaction equipment should be avoided.
Subsurface Drainage
As previously indicated, the retaining wall design parameters are based upon drained backfill
conditions. Consequently, some form of permanent drainage system will be necessary in
conjunction with the appropriate backfill material. Subsurface drainage may consist of either:
• A weep hole drainage system typically consisting of a series of 4-inch diameter holes in
the wall situated slightly above the ground surface elevation on the exposed side of the
wall and at an approximate 8-foot on-center spacing. The weep holes should include a 2
cubic foot pocket of open graded gravel, surrounded by an approved geotextile fabric, at
each weep hole location.
• A 4-inch diameter perforated pipe surrounded by 2 cubic feet of gravel per linear foot of
drain placed behind the wall, above the retaining wall footing. The gravel layer should be
wrapped in a suitable geotextile fabric to reduce the potential for migration of fines. The
footing drain should be extended to daylight or tied into a storm drainage system.
6.8 Pavement Design Parameters
Site preparation in the pavement area should be completed as previously recommended in the
Site Grading Recommendations section of this report. The subsequent pavement
recommendations assume proper drainage and construction monitoring, and are based on either
PCA or CALTRANS design parameters for a twenty (20) year design period. However, these
designs also assume a routine pavement maintenance program to obtain the anticipated 20-year
pavement service life.
Pavement Subgrades
It is anticipated that the new pavements will be primarily supported on a layer of compacted
structural fill, consisting of scarified, thoroughly moisture conditioned and recompacted existing
soils. The near-surface soils generally consist of gravelly sands and sandy gravel. These soils are
generally considered to possess excellent pavement support characteristics, with R-values in the
range of 50 to 60. The subsequent pavement design is therefore based upon an assumed R-value
of 50. Any fill material imported to the site should have support characteristics equal to or greater
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than that of the on-site soils and be placed and compacted under engineering controlled
conditions. It is recommended that R-value testing be performed after completion of rough
grading to verify that the pavement design recommendations presented herein are valid.
Asphaltic Concrete
Presented below are the recommended thicknesses for new flexible pavement structures
consisting of asphaltic concrete over a granular base. The pavement designs are based on the
traffic indices (TI’s) indicated. The client and/or civil engineer should verify that these TI’s are
representative of the anticipated traffic volumes. If the client and/or civil engineer determine that
the expected traffic volume will exceed the applicable traffic index, we should be contacted for
supplementary recommendations. The design traffic indices equate to the following approximate
daily traffic volumes over a 20-year design life, assuming six operational traffic days per week.
Traffic Index No. of Heavy Trucks per Day
4.0 0
5.0 1
6.0 3
7.0 11
8.0 35
For the purpose of the traffic volumes indicated above, a truck is defined as a 5-axle tractor trailer
unit with one 8-kip axle and two 32-kip tandem axles. All of the traffic indices allow for 1,000
automobiles per day.
ASPHALT PAVEMENTS (R = 50)
Materials
Thickness (inches)
Parking
Stalls
(TI = 4.0)
Auto Drive
Lanes
(TI = 5.0)
Truck Traffic
(TI = 6.0) (TI = 7.0) (TI = 8.0)
Asphalt Concrete 3 3 3½ 4 5
Aggregate Base 3 3 4 5 5
Compacted Subgrade
(90% minimum compaction) 12 12 12 12 12
The aggregate base course should be compacted to at least 95 percent of the ASTM D-1557
maximum dry density. The asphaltic concrete should be compacted to at least 95 percent of the
batch plant-reported maximum density. The aggregate base course may consist of crushed
aggregate base (CAB) or crushed miscellaneous base (CMB), which is a recycled gravel, asphalt
and concrete material. The gradation, R-Value, Sand Equivalent, and Percentage Wear of the CAB
or CMB should comply with appropriate specifications contained in the current edition of the
“Greenbook” Standard Specifications for Public Works Construction.
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Portland Cement Concrete
The preparation of the subgrade soils within concrete pavement areas should be performed as
previously described for proposed asphalt pavement areas. The minimum recommended
thicknesses for the Portland Cement Concrete pavement sections are as follows:
PORTLAND CEMENT CONCRETE PAVEMENTS (R = 50)
Materials
Thickness (inches)
Automobile
Parking and
Drive Areas
(TI = 5.0)
Truck Traffic
(TI =6.0) (TI =7.0) (TI =8.0)
PCC 5 5 5½ 6½
Compacted Subgrade
(95% minimum compaction) 12 12 12 12
The concrete should have a 28-day compressive strength of at least 3,000 psi. The maximum
joint spacing within all of the PCC pavements is recommended to be equal to or less than 30
times the pavement thickness. Any reinforcement within the PCC pavements should be
determined by the project structural engineer.
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7.0 GENERAL COMMENTS
This report has been prepared as an instrument of service for use by the client, in order to aid in
the evaluation of this property and to assist the architects and engineers in the design and
preparation of the project plans and specifications. This report may be provided to the
contractor(s) and other design consultants to disclose information relative to the project.
However, this report is not intended to be utilized as a specification in and of itself, without
appropriate interpretation by the project architect, civil engineer, and/or structural engineer. The
reproduction and distribution of this report must be authorized by the client and Southern
California Geotechnical, Inc. Furthermore, any reliance on this report by an unauthorized third
party is at such party’s sole risk, and we accept no responsibility for damage or loss which may
occur. The client(s)’ reliance upon this report is subject to the Engineering Services Agreement,
incorporated into our proposal for this project.
The analysis of this site was based on a subsurface profile interpolated from limited discrete soil
samples. While the materials encountered in the project area are considered to be representative
of the total area, some variations should be expected between boring and trench locations and
sample depths. If the conditions encountered during construction vary significantly from those
detailed herein, we should be contacted immediately to determine if the conditions alter the
recommendations contained herein.
This report has been based on assumed or provided characteristics of the proposed development.
It is recommended that the owner, client, architect, structural engineer, and civil engineer
carefully review these assumptions to ensure that they are consistent with the characteristics of
the proposed development. If discrepancies exist, they should be brought to our attention to
verify that they do not affect the conclusions and recommendations contained herein. We also
recommend that the project plans and specifications be submitted to our office for review to
verify that our recommendations have been correctly interpreted.
The analysis, conclusions, and recommendations contained within this report have been
promulgated in accordance with generally accepted professional geotechnical engineering
practice. No other warranty is implied or expressed.
SITE
PROPOSED WAREHOUSE
SCALE: 1" = 2000'
DRAWN: RB
CHKD: RGT
SCG PROJECT
20G250-1
PLATE 1
SITE LOCATION MAP
FONTANA, CALIFORNIA
SOURCE: USGS TOPOGRAPHIC MAP OF THE DEVORE
QUADRANGLE, SAN BERNARDINO COUNTY, CALIFORNIA, 2018
B-5
N.A.P.
B-1
B-2
B-3
B-4
T-1
T-2
T-4
T-3
B-6
N.A.P.
N.A.P.
N.A.P.
SCALE: 1" = 100'
DRAWN: MD/RB
CHKD: RGT
PLATE 2
SCG PROJECT
20G250-1
FONTANA, CALIFORNIA
PROPOSED WAREHOUSE
BORING AND TRENCH LOCATION PLAN
APPROXIMATE TRENCH LOCATION
NO
R
T
H
So
C
a
l
G
e
o
APPROXIMATE BORING LOCATION
GEOTECHNICAL LEGEND
NOTE: SITE PLAN PLAN PROVIDED BY HUITT-ZOLLARS, INC.
EXISTING STRUCTURES TO BE DEMOLISHED
BORING LOG LEGEND
SAMPLE TYPE GRAPHICAL
SYMBOL SAMPLE DESCRIPTION
AUGER SAMPLE COLLECTED FROM AUGER CUTTINGS, NO FIELD
MEASUREMENT OF SOIL STRENGTH. (DISTURBED)
CORE ROCK CORE SAMPLE: TYPICALLY TAKEN WITH A
DIAMOND-TIPPED CORE BARREL. TYPICALLY USED
ONLY IN HIGHLY CONSOLIDATED BEDROCK.
GRAB 1
SOIL SAMPLE TAKEN WITH NO SPECIALIZED
EQUIPMENT, SUCH AS FROM A STOCKPILE OR THE
GROUND SURFACE. (DISTURBED)
CS CALIFORNIA SAMPLER: 2-1/2 INCH I.D. SPLIT BARREL
SAMPLER, LINED WITH 1-INCH HIGH BRASS RINGS.
DRIVEN WITH SPT HAMMER. (RELATIVELY
UNDISTURBED)
NSR
NO RECOVERY: THE SAMPLING ATTEMPT DID NOT
RESULT IN RECOVERY OF ANY SIGNIFICANT SOIL OR
ROCK MATERIAL.
SPT STANDARD PENETRATION TEST: SAMPLER IS A 1.4
INCH INSIDE DIAMETER SPLIT BARREL, DRIVEN 18
INCHES WITH THE SPT HAMMER. (DISTURBED)
SH SHELBY TUBE: TAKEN WITH A THIN WALL SAMPLE
TUBE, PUSHED INTO THE SOIL AND THEN EXTRACTED.
(UNDISTURBED)
VANE VANE SHEAR TEST: SOIL STRENGTH OBTAINED USING
A 4 BLADED SHEAR DEVICE. TYPICALLY USED IN SOFT
CLAYS-NO SAMPLE RECOVERED.
COLUMN DESCRIPTIONS
DEPTH: Distance in feet below the ground surface.
SAMPLE: Sample Type as depicted above.
BLOW COUNT: Number of blows required to advance the sampler 12 inches using a 140 lb
hammer with a 30-inch drop. 50/3” indicates penetration refusal (>50 blows)
at 3 inches. WH indicates that the weight of the hammer was sufficient to
push the sampler 6 inches or more.
POCKET PEN.: Approximate shear strength of a cohesive soil sample as measured by pocket
penetrometer.
GRAPHIC LOG: Graphic Soil Symbol as depicted on the following page.
DRY DENSITY: Dry density of an undisturbed or relatively undisturbed sample in lbs/ft3.
MOISTURE CONTENT: Moisture content of a soil sample, expressed as a percentage of the dry weight.
LIQUID LIMIT: The moisture content above which a soil behaves as a liquid.
PLASTIC LIMIT: The moisture content above which a soil behaves as a plastic.
PASSING #200 SIEVE: The percentage of the sample finer than the #200 standard sieve.
UNCONFINED SHEAR: The shear strength of a cohesive soil sample, as measured in the unconfined state.
SM
SP
COARSE
GRAINED
SOILS
SW
TYPICAL
DESCRIPTIONS
WELL-GRADED GRAVELS, GRAVEL -
SAND MIXTURES, LITTLE OR NO
FINES
SILTY GRAVELS, GRAVEL - SAND -
SILT MIXTURES
LETTERGRAPH
POORLY-GRADED GRAVELS,
GRAVEL - SAND MIXTURES, LITTLE
OR NO FINES
GC
GM
GP
GW
POORLY-GRADED SANDS,
GRAVELLY SAND, LITTLE OR NO
FINES
SILTS
AND
CLAYS
MORE THAN 50%
OF MATERIAL IS
LARGER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF MATERIAL IS
SMALLER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF COARSE
FRACTION
PASSING ON NO.
4 SIEVE
MORE THAN 50%
OF COARSE
FRACTION
RETAINED ON NO.
4 SIEVE CLAYEY GRAVELS, GRAVEL - SAND -
CLAY MIXTURES
FINE
GRAINED
SOILS
SYMBOLSMAJOR DIVISIONS
SOIL CLASSIFICATION CHART
PT
OH
CH
MH
OL
CL
ML
CLEAN SANDS
SC
SILTY SANDS, SAND - SILT
MIXTURES
CLAYEY SANDS, SAND - CLAY
MIXTURES
INORGANIC SILTS AND VERY FINE
SANDS, ROCK FLOUR, SILTY OR
CLAYEY FINE SANDS OR CLAYEY
SILTS WITH SLIGHT PLASTICITY
INORGANIC CLAYS OF LOW TO
MEDIUM PLASTICITY, GRAVELLY
CLAYS, SANDY CLAYS, SILTY CLAYS,
LEAN CLAYS
ORGANIC SILTS AND ORGANIC
SILTY CLAYS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS FINE SAND OR
SILTY SOILS
INORGANIC CLAYS OF HIGH
PLASTICITY
ORGANIC CLAYS OF MEDIUM TO
HIGH PLASTICITY, ORGANIC SILTS
PEAT, HUMUS, SWAMP SOILS WITH
HIGH ORGANIC CONTENTS
SILTS
AND
CLAYS
GRAVELS WITH
FINES
SAND
AND
SANDY
SOILS (LITTLE OR NO FINES)
SANDS WITH
FINES
LIQUID LIMIT
LESS THAN 50
LIQUID LIMIT
GREATER THAN 50
HIGHLY ORGANIC SOILS
NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS
GRAVEL
AND
GRAVELLY
SOILS
(APPRECIABLE
AMOUNT OF FINES)
(APPRECIABLE
AMOUNT OF FINES)
(LITTLE OR NO FINES)
WELL-GRADED SANDS, GRAVELLY
SANDS, LITTLE OR NO FINES
CLEAN
GRAVELS
19
78
50/3"
35
131
128
1
1
1
ALLUVIUM: Brown fine to coarse Sand, little Silt, little fine to
coarse Gravel, medium dense-dry
Light Gray Gravelly fine to coarse Sand, little Silt, occasional
Cobbles, medium dense to very dense-dry
Boring Terminated at 8' due to refusal on dense Cobbles
Disturbed
Sample
No Sample
Recovery
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-1
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
B-1
SURFACE ELEVATION: 1628.2 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: Dry
CAVE DEPTH: 4 feet
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
5
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
1
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
31
42
2
2
ALLUVIUM: Light Gray Brown fine to coarse Sand, little Silt,
little fine to coarse Gravel, dense-dry
@ 3.5', occasional Cobbles
Boring Terminated at 5.5' due to refusal on dense Cobbles
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-2
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
B-2
SURFACE ELEVATION: 1617.0 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: Dry
CAVE DEPTH: 2 feet
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
5
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
1
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
49
50
53
87
125
123
117
117
3
3
3
4
FILL: Gray Brown Silty fine to medium Sand, trace coarse
Sand, little fine Gravel, dense-damp
ALLUVIUM: Light Gray Brown to Brown fine to coarse Sand,
trace to little Silt, little fine to coarse Gravel, dense-damp
@ 6', occasional Cobbles, very dense
Boring Terminated at 7' due to refusal on dense Cobbles
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-3
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
B-3
SURFACE ELEVATION: 1622.2 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: Dry
CAVE DEPTH: 3.5 feet
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
5
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
1
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
30
50/5"
2
2
ALLUVIUM: Light Gray Gravelly fine to coarse Sand, little Silt,
dense to very dense-dry
@ 3.5', occasional Cobbles
Boring Terminated at 5' due to refusal on dense Cobbles
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-4
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
B-4
SURFACE ELEVATION: 1626.8 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: Dry
CAVE DEPTH: 2.5 feet
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
5
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
1
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
60
40
58
67
63
50/5"
120
1
2
2
2
FILL: Light Gray Brown fine to coarse Sand, little Silt, little fine
Gravel, dense-dry
ALLUVIUM: Gray Brown Gravelly fine to coarse Sand, little
Silt, medium dense to dense-dry
Light Gray to Gray fine to coarse Sand, little fine to coarse
Gravel, trace to little Silt, occasional Cobbles, very dense-dry
Boring Terminated at 15.5' due to refusal on dense Cobbles
Disturbed
Sample
No Sample
Recovery
No Sample
Recovery
Disturbed
Sample
Disturbed
Sample
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-5
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
B-5
SURFACE ELEVATION: 1618.6 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: Dry
CAVE DEPTH: 6 feet
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
5
10
15
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
1
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
29 4
FILL: Dark Brown Silty fine Sand, trace to little medium to
coarse Sand, trace to little fine Gravel, medium dense-damp
Boring Terminated at 2.5' due to refusal on dense Cobbles
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-6
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
B-6
SURFACE ELEVATION: 1612.8 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: Dry
CAVE DEPTH: 2 feet
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
1
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
SOUTHERN CALIFORNIA GEOTECHNICAL
PLATE B-7
TRENCH NO.
T-1
DE
P
T
H
SA
M
P
L
E
DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
MO
I
S
T
U
R
E
(
%
)
EARTH MATERIALS
DESCRIPTION GRAPHIC REPRESENTATION
5
10
15
SCALE: 1" = 5'
TRENCH LOG
KEY TO SAMPLE TYPES:
B - BULK SAMPLE (DISTURBED)
R - RING SAMPLE 2-1/2" DIAMETER
(RELATIVELY UNDISTURBED)
WATER DEPTH: Dry
SEEPAGE DEPTH: Dry
READINGS TAKEN: At Completion
4 to 5-inch thick Gravel layer
A: FILL: Brown Silty fine Sand, little medium to coarse Sand, little fine to
coarse Gravel, trace metal fragments, occasional Cobbles, loose-damp
B: ALLUVIUM: Brown Gravelly fine to coarse Sand, trace to little Silt,
extensive Cobbles, medium dense-dry
@ 2.5 - 4 feet, extensive Cobbles
@8.5 - 10 feet, extensive Cobbles
N 0 E
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
DATE: 1/15/2021
Trench Terminated @ 10 feet
Bottom of Trench Elevation: 1614.2 feet msl
A
EQUIPMENT USED: Backhoe
LOGGED BY: Ryan Bremer
ORIENTATION: N 0 E
ELEVATION: 1624.2 feet msl
4b
2b
2b
2b
Cobbles
B
SOUTHERN CALIFORNIA GEOTECHNICAL
PLATE B-8
TRENCH NO.
T-2
DE
P
T
H
SA
M
P
L
E
DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
MO
I
S
T
U
R
E
(
%
)
EARTH MATERIALS
DESCRIPTION GRAPHIC REPRESENTATION
5
10
15
SCALE: 1" = 5'
TRENCH LOG
KEY TO SAMPLE TYPES:
B - BULK SAMPLE (DISTURBED)
R - RING SAMPLE 2-1/2" DIAMETER
(RELATIVELY UNDISTURBED)
3 to 4-inch thick Gravel layer
A: FILL: Dark Brown Silty fine to coarse Sand, little to some fine to coarse
Gravel, extensive Cobbles, medium dense-dry
B: ALLUVIUM: Brown Gravelly fine to coarse Sand, trace to little Silt,
extensive Cobbles, medium dense-dry to damp
C: Brown Gravelly fine to coarse Sand, trace Silt, extensive Cobbles
medium dense-damp
N 2 W
A
Trench Terminated @ 10 feet
Bottom of Trench Elevation: 1614.1 feet msl
WATER DEPTH: Dry
SEEPAGE DEPTH: Dry
READINGS TAKEN: At Completion
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
DATE: 1/15/2021
EQUIPMENT USED: Backhoe
LOGGED BY: Ryan Bremer
ORIENTATION: N 2 W
ELEVATION: 1624.1 feet msl
b 2
b 2
b 3
b 2
B
C
Cobbles
SOUTHERN CALIFORNIA GEOTECHNICAL
PLATE B-9
TRENCH NO.
T-3
DE
P
T
H
SA
M
P
L
E
DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
MO
I
S
T
U
R
E
(
%
)
EARTH MATERIALS
DESCRIPTION GRAPHIC REPRESENTATION
5
10
15
SCALE: 1" = 5'
TRENCH LOG
KEY TO SAMPLE TYPES:
B - BULK SAMPLE (DISTURBED)
R - RING SAMPLE 2-1/2" DIAMETER
(RELATIVELY UNDISTURBED)
3 to 4-inch Gravel layer
A: FILL: Dark Brown Silty fine Sand, trace to little medium to coarse Sand,
little fine to coarse Gravel, occasional Cobbles, medium dense-damp to
moist
B: ALLUVIUM: Brown Gravelly fine to coarse Sand, extensive Cobbles,
occasional Boulders, medium dense-dry to damp
@ 5 - 6 feet, occasional Boulders
@ 9 feet, little Silt
N 20 W
Ab6
Trench Terminated @ 10 feet
Bottom of Trench Elevation: 1613.5 feet msl
WATER DEPTH: Dry
SEEPAGE DEPTH: Dry
READINGS TAKEN: At Completion
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
DATE: 1/15/2021
EQUIPMENT USED: Backhoe
LOGGED BY: Ryan Bremer
ORIENTATION: N 20 W
ELEVATION: 1623.5 feet msl
b 2
b 2
b 2
B
Cobbles
Boulder
SOUTHERN CALIFORNIA GEOTECHNICAL
PLATE B-10
TRENCH NO.
T-4
DE
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EARTH MATERIALS
DESCRIPTION GRAPHIC REPRESENTATION
5
10
15
SCALE: 1" = 5'
TRENCH LOG
KEY TO SAMPLE TYPES:
B - BULK SAMPLE (DISTURBED)
R - RING SAMPLE 2-1/2" DIAMETER
(RELATIVELY UNDISTURBED)
2 to 3-inch Gravel layer
A: FILL: Brown Silty fine Sand, little medium to coarse Sand, little to some
fine to coarse Gravel, occasional Cobbles, medium dense-dry
B: ALLUVIUM: Brown Gravelly fine to coarse Sand, little to some Silt,
extensive Cobbles, medium dense-damp
C: ALLUVIUM: Brown Gravelly fine to coarse Sand, trace Silt, extensive
Cobbles, occasional Boulders, dense to very dense-dry to damp
N 15 W
A
b 3
Trench Terminated @ 8.5 feet due to refusal on dense Cobbles
Bottom of Trench Elevation: 1609.3 feet msl
WATER DEPTH: Dry
SEEPAGE DEPTH: Dry
READINGS TAKEN: At Completion
JOB NO.: 20G250-1
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
DATE: 1/15/2021
EQUIPMENT USED: Backhoe
LOGGED BY: Ryan Bremer
ORIENTATION: N 15 W
ELEVATION: 1617.8 feet msl
b 3
b 2
b 2
B
C
Classification: FILL: Gray Brown Silty fine to medium Sand, trace coarse Sand
Boring Number:B-3 Initial Moisture Content (%)3
Sample Number:---Final Moisture Content (%)10
Depth (ft)1 to 2 Initial Dry Density (pcf)124.8
Specimen Diameter (in)2.4 Final Dry Density (pcf)133.3
Specimen Thickness (in)1.0 Percent Collapse (%)0.39
Proposed Warehouse
Fontana, California
Project No. 20G250-1
PLATE C-1
0
2
4
6
8
10
12
14
16
18
20
0.1 1 10 100
Consolidation
Strain
(%)
Load (ksf)
Consolidation/Collapse Test Results
Water Added
at 1600 psf
Classification: Light Gray Brown to Brown fine to coarse Sand, trace to little Silt
Boring Number:B-3 Initial Moisture Content (%)3
Sample Number:---Final Moisture Content (%)10
Depth (ft)3 to 4 Initial Dry Density (pcf)123.1
Specimen Diameter (in)2.4 Final Dry Density (pcf)129.9
Specimen Thickness (in)1.0 Percent Collapse (%)0.49
Proposed Warehouse
Fontana, California
Project No. 20G250-1
PLATE C-2
0
2
4
6
8
10
12
14
16
18
20
0.1 1 10 100
Consolidation
Strain
(%)
Load (ksf)
Consolidation/Collapse Test Results
Water Added
at 1600 psf
Proposed Warehouse
Fontana, California
Project No. 20G250-1
PLATE C-3
124
126
128
130
132
134
136
138
140
142
144
146
148
150
0 2 4 6 8 10 12 14 16
Dry
Density
(lbs/ft3)
Moisture Content (%)
Moisture/Density Relationship
ASTM D-1557
Soil ID Number T-1 @ 0-5'
Optimum Moisture (%)4
Maximum Dry Density (pcf)147
Soil Gray Brown Gravelly fine to coarse
Classification Sand, trace to little Silt,
occasional Cobbles
Zero Air Voids Curve:
Specific Gravity = 2.7
Note: Maximum Density
and Optimum Moisture are
based on 40% rock
correction.
Grading Guide Specifications Page 1
GRADING GUIDE SPECIFICATIONS
These grading guide specifications are intended to provide typical procedures for grading operations.
They are intended to supplement the recommendations contained in the geotechnical investigation
report for this project. Should the recommendations in the geotechnical investigation report conflict
with the grading guide specifications, the more site specific recommendations in the geotechnical
investigation report will govern.
General
• The Earthwork Contractor is responsible for the satisfactory completion of all earthwork in
accordance with the plans and geotechnical reports, and in accordance with city, county,
and applicable building codes.
• The Geotechnical Engineer is the representative of the Owner/Builder for the purpose of
implementing the report recommendations and guidelines. These duties are not intended to
relieve the Earthwork Contractor of any responsibility to perform in a workman-like manner,
nor is the Geotechnical Engineer to direct the grading equipment or personnel employed by
the Contractor.
• The Earthwork Contractor is required to notify the Geotechnical Engineer of the anticipated
work and schedule so that testing and inspections can be provided. If necessary, work may
be stopped and redone if personnel have not been scheduled in advance.
• The Earthwork Contractor is required to have suitable and sufficient equipment on the job-
site to process, moisture condition, mix and compact the amount of fill being placed to the
approved compaction. In addition, suitable support equipment should be available to
conform with recommendations and guidelines in this report.
• Canyon cleanouts, overexcavation areas, processed ground to receive fill, key excavations,
subdrains and benches should be observed by the Geotechnical Engineer prior to placement
of any fill. It is the Earthwork Contractor's responsibility to notify the Geotechnical Engineer
of areas that are ready for inspection.
• Excavation, filling, and subgrade preparation should be performed in a manner and
sequence that will provide drainage at all times and proper control of erosion. Precipitation,
springs, and seepage water encountered shall be pumped or drained to provide a suitable
working surface. The Geotechnical Engineer must be informed of springs or water seepage
encountered during grading or foundation construction for possible revision to the
recommended construction procedures and/or installation of subdrains.
Site Preparation
• The Earthwork Contractor is responsible for all clearing, grubbing, stripping and site
preparation for the project in accordance with the recommendations of the Geotechnical
Engineer.
• If any materials or areas are encountered by the Earthwork Contractor which are suspected
of having toxic or environmentally sensitive contamination, the Geotechnical Engineer and
Owner/Builder should be notified immediately.
Grading Guide Specifications Page 2
• Major vegetation should be stripped and disposed of off-site. This includes trees, brush,
heavy grasses and any materials considered unsuitable by the Geotechnical Engineer.
• Underground structures such as basements, cesspools or septic disposal systems, mining
shafts, tunnels, wells and pipelines should be removed under the inspection of the
Geotechnical Engineer and recommendations provided by the Geotechnical Engineer and/or
city, county or state agencies. If such structures are known or found, the Geotechnical
Engineer should be notified as soon as possible so that recommendations can be
formulated.
• Any topsoil, slopewash, colluvium, alluvium and rock materials which are considered
unsuitable by the Geotechnical Engineer should be removed prior to fill placement.
• Remaining voids created during site clearing caused by removal of trees, foundations
basements, irrigation facilities, etc., should be excavated and filled with compacted fill.
• Subsequent to clearing and removals, areas to receive fill should be scarified to a depth of
10 to 12 inches, moisture conditioned and compacted
• The moisture condition of the processed ground should be at or slightly above the optimum
moisture content as determined by the Geotechnical Engineer. Depending upon field
conditions, this may require air drying or watering together with mixing and/or discing.
Compacted Fills
• Soil materials imported to or excavated on the property may be utilized in the fill, provided
each material has been determined to be suitable in the opinion of the Geotechnical
Engineer. Unless otherwise approved by the Geotechnical Engineer, all fill materials shall be
free of deleterious, organic, or frozen matter, shall contain no chemicals that may result in
the material being classified as “contaminated,” and shall be very low to non-expansive with
a maximum expansion index (EI) of 50. The top 12 inches of the compacted fill should
have a maximum particle size of 3 inches, and all underlying compacted fill material a
maximum 6-inch particle size, except as noted below.
• All soils should be evaluated and tested by the Geotechnical Engineer. Materials with high
expansion potential, low strength, poor gradation or containing organic materials may
require removal from the site or selective placement and/or mixing to the satisfaction of the
Geotechnical Engineer.
• Rock fragments or rocks less than 6 inches in their largest dimensions, or as otherwise
determined by the Geotechnical Engineer, may be used in compacted fill, provided the
distribution and placement is satisfactory in the opinion of the Geotechnical Engineer.
• Rock fragments or rocks greater than 12 inches should be taken off-site or placed in
accordance with recommendations and in areas designated as suitable by the Geotechnical
Engineer. These materials should be placed in accordance with Plate D-8 of these Grading
Guide Specifications and in accordance with the following recommendations:
• Rocks 12 inches or more in diameter should be placed in rows at least 15 feet apart, 15
feet from the edge of the fill, and 10 feet or more below subgrade. Spaces should be
left between each rock fragment to provide for placement and compaction of soil
around the fragments.
• Fill materials consisting of soil meeting the minimum moisture content requirements and
free of oversize material should be placed between and over the rows of rock or
Grading Guide Specifications Page 3
concrete. Ample water and compactive effort should be applied to the fill materials as
they are placed in order that all of the voids between each of the fragments are filled
and compacted to the specified density.
• Subsequent rows of rocks should be placed such that they are not directly above a row
placed in the previous lift of fill. A minimum 5-foot offset between rows is
recommended.
• To facilitate future trenching, oversized material should not be placed within the range
of foundation excavations, future utilities or other underground construction unless
specifically approved by the soil engineer and the developer/owner representative.
• Fill materials approved by the Geotechnical Engineer should be placed in areas previously
prepared to receive fill and in evenly placed, near horizontal layers at about 6 to 8 inches in
loose thickness, or as otherwise determined by the Geotechnical Engineer for the project.
• Each layer should be moisture conditioned to optimum moisture content, or slightly above,
as directed by the Geotechnical Engineer. After proper mixing and/or drying, to evenly
distribute the moisture, the layers should be compacted to at least 90 percent of the
maximum dry density in compliance with ASTM D-1557-78 unless otherwise indicated.
• Density and moisture content testing should be performed by the Geotechnical Engineer at
random intervals and locations as determined by the Geotechnical Engineer. These tests
are intended as an aid to the Earthwork Contractor, so he can evaluate his workmanship,
equipment effectiveness and site conditions. The Earthwork Contractor is responsible for
compaction as required by the Geotechnical Report(s) and governmental agencies.
• Fill areas unused for a period of time may require moisture conditioning, processing and
recompaction prior to the start of additional filling. The Earthwork Contractor should notify
the Geotechnical Engineer of his intent so that an evaluation can be made.
• Fill placed on ground sloping at a 5-to-1 inclination (horizontal-to-vertical) or steeper should
be benched into bedrock or other suitable materials, as directed by the Geotechnical
Engineer. Typical details of benching are illustrated on Plates D-2, D-4, and D-5.
• Cut/fill transition lots should have the cut portion overexcavated to a depth of at least 3 feet
and rebuilt with fill (see Plate D-1), as determined by the Geotechnical Engineer.
• All cut lots should be inspected by the Geotechnical Engineer for fracturing and other
bedrock conditions. If necessary, the pads should be overexcavated to a depth of 3 feet
and rebuilt with a uniform, more cohesive soil type to impede moisture penetration.
• Cut portions of pad areas above buttresses or stabilizations should be overexcavated to a
depth of 3 feet and rebuilt with uniform, more cohesive compacted fill to impede moisture
penetration.
• Non-structural fill adjacent to structural fill should typically be placed in unison to provide
lateral support. Backfill along walls must be placed and compacted with care to ensure that
excessive unbalanced lateral pressures do not develop. The type of fill material placed
adjacent to below grade walls must be properly tested and approved by the Geotechnical
Engineer with consideration of the lateral earth pressure used in the design.
Grading Guide Specifications Page 4
Foundations
• The foundation influence zone is defined as extending one foot horizontally from the outside
edge of a footing, and proceeding downward at a ½ horizontal to 1 vertical (0.5:1)
inclination.
• Where overexcavation beneath a footing subgrade is necessary, it should be conducted so
as to encompass the entire foundation influence zone, as described above.
• Compacted fill adjacent to exterior footings should extend at least 12 inches above
foundation bearing grade. Compacted fill within the interior of structures should extend to
the floor subgrade elevation.
Fill Slopes
• The placement and compaction of fill described above applies to all fill slopes. Slope
compaction should be accomplished by overfilling the slope, adequately compacting the fill
in even layers, including the overfilled zone and cutting the slope back to expose the
compacted core
• Slope compaction may also be achieved by backrolling the slope adequately every 2 to 4
vertical feet during the filling process as well as requiring the earth moving and compaction
equipment to work close to the top of the slope. Upon completion of slope construction,
the slope face should be compacted with a sheepsfoot connected to a sideboom and then
grid rolled. This method of slope compaction should only be used if approved by the
Geotechnical Engineer.
• Sandy soils lacking in adequate cohesion may be unstable for a finished slope condition and
therefore should not be placed within 15 horizontal feet of the slope face.
• All fill slopes should be keyed into bedrock or other suitable material. Fill keys should be at
least 15 feet wide and inclined at 2 percent into the slope. For slopes higher than 30 feet,
the fill key width should be equal to one-half the height of the slope (see Plate D-5).
• All fill keys should be cleared of loose slough material prior to geotechnical inspection and
should be approved by the Geotechnical Engineer and governmental agencies prior to filling.
• The cut portion of fill over cut slopes should be made first and inspected by the
Geotechnical Engineer for possible stabilization requirements. The fill portion should be
adequately keyed through all surficial soils and into bedrock or suitable material. Soils
should be removed from the transition zone between the cut and fill portions (see Plate D-
2).
Cut Slopes
• All cut slopes should be inspected by the Geotechnical Engineer to determine the need for
stabilization. The Earthwork Contractor should notify the Geotechnical Engineer when slope
cutting is in progress at intervals of 10 vertical feet. Failure to notify may result in a delay
in recommendations.
• Cut slopes exposing loose, cohesionless sands should be reported to the Geotechnical
Engineer for possible stabilization recommendations.
• All stabilization excavations should be cleared of loose slough material prior to geotechnical
inspection. Stakes should be provided by the Civil Engineer to verify the location and
dimensions of the key. A typical stabilization fill detail is shown on Plate D-5.
Grading Guide Specifications Page 5
• Stabilization key excavations should be provided with subdrains. Typical subdrain details
are shown on Plates D-6.
Subdrains
• Subdrains may be required in canyons and swales where fill placement is proposed. Typical
subdrain details for canyons are shown on Plate D-3. Subdrains should be installed after
approval of removals and before filling, as determined by the Soils Engineer.
• Plastic pipe may be used for subdrains provided it is Schedule 40 or SDR 35 or equivalent.
Pipe should be protected against breakage, typically by placement in a square-cut
(backhoe) trench or as recommended by the manufacturer.
• Filter material for subdrains should conform to CALTRANS Specification 68-1.025 or as
approved by the Geotechnical Engineer for the specific site conditions. Clean ¾-inch
crushed rock may be used provided it is wrapped in an acceptable filter cloth and approved
by the Geotechnical Engineer. Pipe diameters should be 6 inches for runs up to 500 feet
and 8 inches for the downstream continuations of longer runs. Four-inch diameter pipe
may be used in buttress and stabilization fills.
GRADING GUIDE SPECIFICATIONS
NOT TO SCALE
DRAWN: JAS
CHKD: GKM
PLATE D-2
FILL ABOVE CUT SLOPE DETAIL
9' MIN.
4' TYP.
MINIMUM 1' TILT BACK
OR 2% SLOPE
(WHICHEVER IS GREATER)
REMOVE
U
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B
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BENCHING DIMENSIONS IN ACCORDANCE
WITH PLAN OR AS RECOMMENDED
BY THE GEOTECHNICAL ENGINEER
CUT SLOPE TO BE CONSTRUCTED
PRIOR TO PLACEMENT OF FILL
BEDROCK OR APPROVED
COMPETENT MATERIAL
CUT SLOPE
NATURAL GRADE
CUT/FILL CONTACT TO BE
SHOWN ON "AS-BUILT"
COMPETENT MATERIAL
CUT/FILL CONTACT SHOWN
ON GRADING PLAN
NEW COMPACTED FILL
10' TYP.
KEYWAY IN COMPETENT MATERIAL
MINIMUM WIDTH OF 15 FEET OR AS
RECOMMENDED BY THE GEOTECHNICAL
ENGINEER. KEYWAY MAY NOT BE
REQUIRED IF FILL SLOPE IS LESS THAN 5
FEET IN HEIGHT AS RECOMMENDED BY
THE GEOTECHNICAL ENGINEER.
GRADING GUIDE SPECIFICATIONS
NOT TO SCALE
DRAWN: JAS
CHKD: GKM
PLATE D-4
FILL ABOVE NATURAL SLOPE DETAIL
10' TYP.
4' TYP.
(WHICHEVER IS GREATER)
OR 2% SLOPE
MINIMUM 1' TILT BACK
REMOVE U
N
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B
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NEW COMPACTED FILL
COMPETENT MATERIAL
KEYWAY IN COMPETENT MATERIAL.
RECOMMENDED BY THE GEOTECHNIAL
ENGINEER. KEYWAY MAY NOT BE REQUIRED
IF FILL SLOPE IS LESS THAN 5' IN HEIGHT
AS RECOMMENDED BY THE GEOTECHNICAL
ENGINEER.
2' MINIMUM
KEY DEPTH
OVERFILL REQUIREMENTS
PER GRADING GUIDE SPECIFICATIONS
TOE OF SLOPE SHOWN
ON GRADING PLAN
BACKCUT - VARIES
PLACE COMPACTED BACKFILL
TO ORIGINAL GRADE
PROJECT SLOPE GRADIENT
(1:1 MAX.)
NOTE:
BENCHING SHALL BE REQUIRED
WHEN NATURAL SLOPES ARE
EQUAL TO OR STEEPER THAN 5:1
OR WHEN RECOMMENDED BY
THE GEOTECHNICAL ENGINEER.
FINISHED SLOPE FACE
MINIMUM WIDTH OF 15 FEET OR AS
BENCHING DIMENSIONS IN ACCORDANCE
WITH PLAN OR AS RECOMMENDED
BY THE GEOTECHNICAL ENGINEER
GRADING GUIDE SPECIFICATIONS
NOT TO SCALE
DRAWN: JAS
CHKD: GKM
PLATE D-5
STABILIZATION FILL DETAIL
FACE OF FINISHED SLOPE
COMPACTED FILL
MINIMUM 1' TILT BACK
OR 2% SLOPE
(WHICHEVER IS GREATER)
10' TYP.
2' MINIMUM
KEY DEPTH
3' TYPICAL
BLANKET FILL IF RECOMMENDED
BY THE GEOTECHNICAL ENGINEER
COMPETENT MATERIAL ACCEPTABLE
TO THE SOIL ENGINEER
KEYWAY WIDTH, AS SPECIFIED
BY THE GEOTECHNICAL ENGINEER
TOP WIDTH OF FILL
AS SPECIFIED BY THE
GEOTECHNICAL ENGINEER
BENCHING DIMENSIONS IN ACCORDANCE
WITH PLAN OR AS RECOMMENDED
BY THE GEOTECHNICAL ENGINEER
4' TYP.
PROPOSED WAREHOUSE
DRAWN: JLL
CHKD: RGT
SCG PROJECT
20G250-1
PLATE E-1
SEISMIC DESIGN PARAMETERS - 2019 CBC
FONTANA, CALIFORNIA
SOURCE: SEAOC/OSHPD Seismic Design Maps Tool
<https://seismicmaps.org/>
22885 Savi Ranch Parkway Suite E Yorba Linda California 92887
voice: (714) 685-1115 fax: (714) 685-1118 www.socalgeo.com
February 5, 2021
Seefried Industrial Properties, Inc.
2321 Rosecrans Avenue, Suite 2220
El Segundo, California 90245
Attention: Mr. Scott Irwin
Senior Vice President – Southern California
Project No.: 20G250-2
Subject: Results of Infiltration Testing
Proposed Warehouse
NEC Sierra Avenue and Clubhouse Drive
Fontana, California
Reference: Geotechnical Investigation, Proposed Warehouse, NEC Sierra Avenue and Clubhouse
Drive, Fontana, California, prepared by Southern California Geotechnical, Inc. (SCG)
for Seefried Industrial Properties, Inc., SCG Project No. 20G250-1, dated February 5,
2021.
Mr. Irwin:
In accordance with your request, we have conducted infiltration testing at the subject site. We are
pleased to present this report summarizing the results of the infiltration testing and our design
recommendations.
Scope of Services
The scope of services performed for this project was in general accordance with our Proposal No.
20P444, dated December 16, 2020. The scope of services included site reconnaissance, subsurface
exploration, field testing, and engineering analysis to determine the infiltration rate s of the on-site
soils. The infiltration testing was performed in general accordance with the guidelines published in
Riverside County – Low Impact Development BMP Design Handbook – Section 2.3 of Appendix A,
prepared for the Riverside County Department of Environmental Health (RCDEH), dated December,
2013. The San Bernardino County standards defer to the guidelines published by the RCDEH.
Site and Project Description
The subject site is located at the northeast corner of Sierra Avenue and Clubhouse Drive in Fontana,
California. The site is bounded to the north and south by existing commercial/industrial buildings, to
the west by Sierra Avenue, and to the east by Mango Avenue . The general location of the site is
illustrated on the Site Location Map, enclosed as Plate 1 of this report.
The site consists of a rectangular-shaped property, 18.44± acres in size. The overall site is presently
developed with four (4) commercial/industrial buildings ranging from 5,000 to 25,000± ft² in size.
The northwestern quadrant is developed with one building and is utilized as a wooden pallet facility.
The northeastern quadrant is developed with one building and is utilized as a carnival attraction
repair facility with truck trailer parking. The southwestern quadrant is developed with one building
and open-graded gravel pavements and is utilized for truck trailer storage. The southeastern
quadrant is developed with one building and is utilized as a storage facility. The existing buildings
Proposed Warehouse – Fontana, CA
Project No. 20G250-2
Page 2
are single-story metal-framed structures and are assumed to be supported on conventional shallow
foundations with concrete slab-on-grade floors. Ground surface cover consists mainly of open
graded gravel and exposed soil, with asphaltic concrete (AC) or Portland cement concrete (PCC)
pavements surrounding the buildings. Little to no vegetation was encountered throughout the
overall site. Few large trees are present between the northwest and northeast quadrants.
Topographic information was obtained from a conceptual site plan prepared by Huitt-Zollars, Inc.
Based on our review of this plan, the existing site topography generally slopes downward to the
south at a gradient of 3± percent. The elevation at the subject site ranges from 1630± feet mean
sea level (msl) in the northern region of the site to 1612± feet msl in the southern region.
Proposed Development
Based on the conceptual plan provided to our office by the client, the subject site will be developed
with a 389,140± ft² warehouse, located in the north-central region of the site. Dock-high doors will
be constructed along a portion of the south building wall. The proposed building is expected to be
surrounded by AC pavements in the parking and drive areas, PCC pavements in the loading dock
area, and concrete flatwork and landscaped planters throughout the site.
We understand that the proposed development will include on -site stormwater infiltration. The
infiltration system will consist of a below-grade chamber system located in the south to
southwestern region of the site.
Concurrent Study
Southern California Geotechnical, Inc. (SCG) concurrently conducted a geotechnical investigation at
the subject site, referenced above. As a part of this study, six (6) borings (identified as Boring Nos.
B-1 through B-6) were advanced to depths of 2½ to 15½± feet below existing site grades. In
addition, four (4) exploratory trenches (identified as Trench Nos. T-1 through T-4) were excavated
using a rubber-tire backhoe to depths of 8½ to 10± feet. Artificial fill soils were encountered at the
ground surface at Boring Nos. B-3, B-5, and B-6, and at all of the trench locations, extending to
depths of 1 to 3± feet. The fill soils consist of loose to dense silty fine to coarse sands, fine to
coarse sands, and silty fine sands. Occasional cobbles and variable gravel content were encountered
throughout the artificial fill. Boring No. B-6 was terminated within the artificial fill at a depth of 2½±
feet due to very dense materials and extensive cobble content. Native alluvium was encountered at
the ground surface or below the fill soils at all of the boring and trench locations, extending to at
least the maximum depth explored of 15½± feet, with the exception of Boring No. B-6. The
alluvium generally consists of medium dense to very dense fine to coarse sands and gravelly fine to
coarse sands. Extensive cobble content and variable silt content were encountered throughout the
alluvial strata. In addition, occasional boulder content was encountered in Trench Nos. T -3 and T-4
as shallow as 2½± feet from the ground surface.
Groundwater
Free water was not encountered during drilling or trenching at any location. Based on the moisture
contents of the recovered soil samples, the static groundwater table is considered to have existed at
a depth in excess of 15½± feet below existing site grades, at the time of the subsurface
investigation.
Proposed Warehouse – Fontana, CA
Project No. 20G250-2
Page 3
As a part of our research, we reviewed available groundwater data in order to determine
groundwater levels for the site. Recent water level data was obtained from the California
Department of Water Resources Water Data Library website,
https://wdl.water.ca.gov/waterdatalibrary/. The nearest monitoring well on record is located 3,180±
feet southeast of the site. Water level readings within this monitoring well indicate a groundwater
level of 320± feet below the ground surface in March 1994.
As part of our research, we reviewed available groundwater data in order to determine the historic
high groundwater level for the site. The primary reference used to determine the historic
groundwater depths in area of the subject site is Watermaster Support Ser vices, Western Municipal
Water District and the San Bernardino Valley Water Conservation District Cooperative Well
Measuring Program, dated Fall 2015. A well titled Mid -Valley (Fontana) F-07 exists 1,500± feet
southeast of the site and indicates a high groundwater level of 330± feet below the ground surface
in April 2000.
Subsurface Exploration
Scope of Exploration
The subsurface exploration conducted for the infiltration testing consisted of two (2) infiltration test
borings, advanced to a depth of 7± feet below the existing site grades. The infiltration borings were
advanced using a truck-mounted drilling rig, equipped with 8-inch-diameter hollow-stem augers and
were logged during drilling by a member of our staff. The approximate locations of the infiltration
test borings (identified as I-1 and I-2) are indicated on the Infiltration Test Location Plan, enclosed
as Plate 2 of this report.
Upon the completion of the infiltration borings, the bottom of each test boring was covered with 2±
inches of clean ¾-inch gravel. A sufficient length of 3-inch-diameter perforated PVC casing was then
placed into each test hole so that the PVC casing extended from the bottom of the test hole to the
ground surface. Clean ¾-inch gravel was then installed in the annulus surrounding the PVC casing.
Geotechnical Conditions
Artificial Fill
Artificial fill soils were encountered at the ground surface of both infiltration boring locations,
extending to depths of 3± below existing site grades. The fill soils consist of medium dense silty fine
sands with some fine to coarse gravel content and ext ensive cobbles. The fill soils contained a
disturbed appearance, resulting in the classification of artificial fill.
Alluvium
Native alluvial soils were encountered beneath the fill soils surface at both of the infiltration boring
locations, extending to at least the maximum depth explored of 7± feet below existing site grades.
The alluvial soils consisted of medium dense to very dense gravelly fine to coarse sands to fine to
coarse sandy gravels. The Boring Logs, which illustrate the conditions encountered at the boring
locations, are included with this report.
Proposed Warehouse – Fontana, CA
Project No. 20G250-2
Page 4
Infiltration Testing
As previously mentioned, the infiltration testing was performed in general accordance with the
guidelines published in Riverside County – Low Impact Development BMP Design Handbook –
Section 2.3 of Appendix A, which apply to San Bernardino County.
Pre-soaking
In accordance with the county infiltration standards for sandy soils, all infiltration test borings were
pre-soaked 2 hours prior to the infiltration testing or until all of the water had percolated through
the test holes. The pre-soaking process consisted of filling test borings by inverting a full 5-gallon
bottle of clear water supported over each hole so that the water flow into the hole holds constant at
a level at least 5 times the hole’s radius above the gravel at the bottom of each hole. Pre-soaking
was completed after all of the water had percolated through the test holes.
Infiltration Testing
Following the pre-soaking process of the infiltration test borings, SCG performed the infiltration
testing. Each test hole was filled with water to a depth of at least 5 times the hole’s radius above
the gravel at the bottom of the test holes. In accordance with the San Bernardino County guidelines,
since “sandy soils” were encountered at the bottom of both of the infiltration test borings (where 6
inches of water infiltrated into the surrounding soils for two consecutive 25 -minute readings),
readings were taken at 5-minute and 10-minute intervals for a total of 1 hour. After each reading,
water was added to the borings so that the depth of the water was at least 5 times the radius of the
hole. The water level readings are presented on the spreadsheets enclosed with this report. The
infiltration rates for each of the timed intervals are also tabulated on the spreadsheets.
The infiltration rates from the test are tabulated in inches per hour. In accordance with the typically
accepted practice, it is recommended that the most conservative reading from the latter part of the
infiltration tests be used as the design infiltration rate. The rates are summarized below:
Infiltration
Test No.
Depth
(feet) Soil Description Infiltration Rate
(inches/hour)
I-1 7 Gravelly fine to coarse Sand, trace Silt 8.6
I-2 7 Gravelly fine to coarse Sand to fine to coarse
Sandy Gravel, trace Silt 14.6
Laboratory Testing
Moisture Content
The moisture contents for the recovered soil samples within the boring s were determined in
accordance with ASTM D-2216 and are expressed as a percentage of the dry wei ght. These test
results are presented on the Boring Logs.
Grain Size Analysis
The grain size distribution of selected soils collected from the base of each infiltration test boring
Proposed Warehouse – Fontana, CA
Project No. 20G250-2
Page 5
have been determined using a range of wire mesh screens. These tests were performed in general
accordance with ASTM D-422 and/or ASTM D-1140. The weight of the portion of the sample
retained on each screen is recorded and the percentage finer or coarser of the total weight is
calculated. The results of these tests are presented on Plates C-1 through C-2 of this report.
Design Recommendations
Two (2) infiltration tests were performed at the subject site. As noted above, the infiltration rates at
these locations vary from 8.6 to 14.6 inches per hour. Based on the infiltration test results, we
recommend an infiltration rate of 8.6 inches per hour to be used for the proposed
below-grade chamber system in the south-southwestern area of the site.
We recommend that a representative from the geotechnical engineer be on-site during the
construction of the proposed infiltration systems to identify the soil classification at the base of each
system. It should be confirmed that the soils at the base of the proposed infiltration systems
correspond with those presented in this report to ensure that the performance of the systems will be
consistent with the rates reported herein.
The design of the storm water infiltration system should be performed by the project civil engine er,
in accordance with the City of Fontana and/or County of San Bernardino guidelines. It is
recommended that the system be constructed so as to facilitate removal of silt and clay, or other
deleterious materials from any water that may enter the system s. The presence of such materials
would decrease the effective infiltration rates. It is recommended that the project civil
engineer apply an appropriate factor of safety. The infiltration rate recommended above
is based on the assumption that only clean water will be introduced to the subsurface
profile. Any fines, debris, or organic materials could significantly impact the infiltration
rate. It should be noted that the recommended infiltration rate s are based on infiltration testing at
two (2) discrete locations and that the overall infiltration rates of the proposed infiltration systems
could vary considerably.
Construction Considerations
The infiltration rates presented in this report are specific to the tested locations and tested depths.
Infiltration rates can be significantly reduced if the soils are exposed to excessive disturbance or
compaction during construction. Therefore, the subgrade soils within proposed infiltration system
areas should not be over-excavated, undercut or compacted in any significant manner. It is
recommended that a note to this effect be added to the project plans and/or
specifications.
Infiltration versus Permeability
Infiltration rates are based on unsaturated flow. As water is introduced into soils by infiltration, the
soils become saturated and the wetting front advances from the unsaturated zo ne to the saturated
zone. Once the soils become saturated, infiltration rates become zero, and water can only move
through soils by hydraulic conductivity at a rate determined by pressure head and soil permeability.
The infiltration rate presented herein was determined in accordance with the San Bernardino County
guidelines and is considered valid for the time and place of the actual test. Changes in soil mo isture
content will affect the infiltration rate. Infiltration rates should be expected to decrease until the
soils become saturated. Soil permeability values will then govern groundwater movement.
Permeability values may be on the order of 10 to 20 times less than infiltration rates. T he system
Proposed Warehouse – Fontana, CA
Project No. 20G250-2
Page 6
designer should incorporate adequate factors of safety and a llow for overflow design into
appropriate traditional storm drain systems, which would transport storm water off -site.
Location of Infiltration System
The use of on-site storm water infiltration systems carries a risk of creating adverse geotechnical
conditions. Increasing the moisture content of the soil can cause the soil to lose internal shear
strength and increase its compressibility, resulting in a change in the designed engineering
properties. Overlying structures and pavements in the infiltration area could potentially be damaged
due to saturation of subgrade soils. The proposed infiltration system for this site should be
located at least 25 feet away from any descending slopes and structures, including
retaining walls. Even with this provision of locating the infiltration system at least 25 feet from the
building, it is possible that infiltrating water into the subsurface soils could have an adverse effect on
the proposed or existing structures. It should also be noted that utility trenches which happ en to
collect storm water can also serve as conduits to transmit storm water toward the structure,
depending on the slope of the utility trench. Therefore, consideration should also be g iven to the
proposed locations of underground utilities which may pass near the proposed infiltration system.
General Comments
This report has been prepared as an instrument of service for use by the client in order to aid in the
evaluation of this property and to assist the architects and engineers in the design and prepara tion
of the project plans and specifications. This report may be provided to the contractor(s) and other
design consultants to disclose information relative to the project. However, this report is not
intended to be utilized as a specification in and of itself, without appropriate interpretation by the
project architect, structural engineer, and/or civil engineer. The design of the proposed storm water
infiltration system is the responsibility of the civil engineer. The role of the geotechnical engineer is
limited to determination of infiltration rate only. By using the design infiltration rate contained
herein, the civil engineer agrees to indemnify, defend, and hold harmless the geotechn ical engineer
for all aspects of the design and performance of the proposed storm water infiltration system. The
reproduction and distribution of this report must be authorized by the client and Southern California
Geotechnical, Inc. Furthermore, any relia nce on this report by an unauthorized third party is at such
party’s sole risk, and we accept no responsibility for damage or loss which may occur.
The analysis of this site was based on a subsurface profile interpolated from limited discrete soil
samples. While the materials encountered in the project area are considered t o be representative of
the total area, some variations should be expected between boring locations and testing depths. If
the conditions encountered during construction vary significantl y from those detailed herein, we
should be contacted immediately to de termine if the conditions alter the recommendations
contained herein.
This report has been based on assumed or provided characteristics of the proposed development. It
is recommended that the owner, client, architect, structural engineer, and civil engineer carefully
review these assumptions to ensure that they are consistent with the characteristics of the proposed
development. If discrepancies exist, they should be brought to our attention to verify that they do
not affect the conclusions and recommendations contained herein. We also recommend that the
project plans and specifications be submitted to our office for review to verify that our
recommendations have been correctly interpreted. The analysis, conclusions, and recommendations
contained within this report have been promulgated in accordance with generally accepted
professional geotechnical engineering practice. No other warranty is implied or expressed .
Proposed Warehouse – Fontana, CA
Project No. 20G250-2
Page 7
Closure
We sincerely appreciate the opportunity to be of service on this project. We look forward to
providing additional consulting services during the course of the project. If we may be of further
assistance in any manner, please contact our office.
Respectfully Submitted,
SOUTHERN CALIFORNIA GEOTECHNICAL, INC.
Ryan Bremer Ricardo Frias, RCE 91772
Staff Engineer Staff Engineer
Robert G. Trazo, GE 2655
Principal Engineer
Distribution: (1) Addressee
Enclosures: Plate 1 - Site Location Map
Plate 2: Infiltration Test Location Plan
Boring Log Legend and Logs (4 pages)
Infiltration Test Results Spreadsheets (2 pages)
Grain Size Distribution Graphs (2 pages)
SITE
PROPOSED WAREHOUSE
SCALE: 1" = 2000'
DRAWN: RB
CHKD: RGT
SCG PROJECT
20G250-2
PLATE 1
SITE LOCATION MAP
FONTANA, CALIFORNIA
SOURCE: USGS TOPOGRAPHIC MAP OF THE DEVORE
QUADRANGLE, SAN BERNARDINO COUNTY, CALIFORNIA, 2018
B-5
N.A.P.
B-1
B-2
B-3
B-4
T-1
T-2
T-3
B-6
I-1 I-2
N.A.P.
N.A.P.
N.A.P.
T-4
SCALE: 1" = 100'
DRAWN: MD/RB
CHKD: RGT
PLATE 2
SCG PROJECT
20G250-2
FONTANA, CALIFORNIA
PROPOSED WAREHOUSE
INFILTRATION TEST LOCATION PLAN
APPROXIMATE TRENCH LOCATION
NO
R
T
H
So
C
a
l
G
e
o
APPROXIMATE INFILTRATION LOCATION
APPROXIMATE BORING LOCATION
GEOTECHNICAL LEGEND
NOTE: SITE PLAN PLAN PROVIDED BY HUITT-ZOLLARS, INC.
PROPOSED INFILTRATION SYSTEM
(SCG PROJECT NO. 20G250-1)
(SCG PROJECT NO. 20G250-1)
EXISTING STRUCTURES TO BE DEMOLISHED
BORING LOG LEGEND
SAMPLE TYPE GRAPHICAL
SYMBOL SAMPLE DESCRIPTION
AUGER SAMPLE COLLECTED FROM AUGER CUTTINGS, NO FIELD
MEASUREMENT OF SOIL STRENGTH. (DISTURBED)
CORE ROCK CORE SAMPLE: TYPICALLY TAKEN WITH A
DIAMOND-TIPPED CORE BARREL. TYPICALLY USED
ONLY IN HIGHLY CONSOLIDATED BEDROCK.
GRAB 1
SOIL SAMPLE TAKEN WITH NO SPECIALIZED
EQUIPMENT, SUCH AS FROM A STOCKPILE OR THE
GROUND SURFACE. (DISTURBED)
CS CALIFORNIA SAMPLER: 2-1/2 INCH I.D. SPLIT BARREL
SAMPLER, LINED WITH 1-INCH HIGH BRASS RINGS.
DRIVEN WITH SPT HAMMER. (RELATIVELY
UNDISTURBED)
NSR
NO RECOVERY: THE SAMPLING ATTEMPT DID NOT
RESULT IN RECOVERY OF ANY SIGNIFICANT SOIL OR
ROCK MATERIAL.
SPT STANDARD PENETRATION TEST: SAMPLER IS A 1.4
INCH INSIDE DIAMETER SPLIT BARREL, DRIVEN 18
INCHES WITH THE SPT HAMMER. (DISTURBED)
SH SHELBY TUBE: TAKEN WITH A THIN WALL SAMPLE
TUBE, PUSHED INTO THE SOIL AND THEN EXTRACTED.
(UNDISTURBED)
VANE VANE SHEAR TEST: SOIL STRENGTH OBTAINED USING
A 4 BLADED SHEAR DEVICE. TYPICALLY USED IN SOFT
CLAYS-NO SAMPLE RECOVERED.
COLUMN DESCRIPTIONS
DEPTH: Distance in feet below the ground surface.
SAMPLE: Sample Type as depicted above.
BLOW COUNT: Number of blows required to advance the sampler 12 inches using a 140 lb
hammer with a 30-inch drop. 50/3” indicates penetration refusal (>50 blows)
at 3 inches. WH indicates that the weight of the hammer was sufficient to
push the sampler 6 inches or more.
POCKET PEN.: Approximate shear strength of a cohesive soil sample as measured by pocket
penetrometer.
GRAPHIC LOG: Graphic Soil Symbol as depicted on the following page.
DRY DENSITY: Dry density of an undisturbed or relatively undisturbed sample in lbs/ft3.
MOISTURE CONTENT: Moisture content of a soil sample, expressed as a percentage of the dry weight.
LIQUID LIMIT: The moisture content above which a soil behaves as a liquid.
PLASTIC LIMIT: The moisture content above which a soil behaves as a plastic.
PASSING #200 SIEVE: The percentage of the sample finer than the #200 standard sieve.
UNCONFINED SHEAR: The shear strength of a cohesive soil sample, as measured in the unconfined state.
SM
SP
COARSE
GRAINED
SOILS
SW
TYPICAL
DESCRIPTIONS
WELL-GRADED GRAVELS, GRAVEL -
SAND MIXTURES, LITTLE OR NO
FINES
SILTY GRAVELS, GRAVEL - SAND -
SILT MIXTURES
LETTERGRAPH
POORLY-GRADED GRAVELS,
GRAVEL - SAND MIXTURES, LITTLE
OR NO FINES
GC
GM
GP
GW
POORLY-GRADED SANDS,
GRAVELLY SAND, LITTLE OR NO
FINES
SILTS
AND
CLAYS
MORE THAN 50%
OF MATERIAL IS
LARGER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF MATERIAL IS
SMALLER THAN
NO. 200 SIEVE
SIZE
MORE THAN 50%
OF COARSE
FRACTION
PASSING ON NO.
4 SIEVE
MORE THAN 50%
OF COARSE
FRACTION
RETAINED ON NO.
4 SIEVE CLAYEY GRAVELS, GRAVEL - SAND -
CLAY MIXTURES
FINE
GRAINED
SOILS
SYMBOLSMAJOR DIVISIONS
SOIL CLASSIFICATION CHART
PT
OH
CH
MH
OL
CL
ML
CLEAN SANDS
SC
SILTY SANDS, SAND - SILT
MIXTURES
CLAYEY SANDS, SAND - CLAY
MIXTURES
INORGANIC SILTS AND VERY FINE
SANDS, ROCK FLOUR, SILTY OR
CLAYEY FINE SANDS OR CLAYEY
SILTS WITH SLIGHT PLASTICITY
INORGANIC CLAYS OF LOW TO
MEDIUM PLASTICITY, GRAVELLY
CLAYS, SANDY CLAYS, SILTY CLAYS,
LEAN CLAYS
ORGANIC SILTS AND ORGANIC
SILTY CLAYS OF LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS FINE SAND OR
SILTY SOILS
INORGANIC CLAYS OF HIGH
PLASTICITY
ORGANIC CLAYS OF MEDIUM TO
HIGH PLASTICITY, ORGANIC SILTS
PEAT, HUMUS, SWAMP SOILS WITH
HIGH ORGANIC CONTENTS
SILTS
AND
CLAYS
GRAVELS WITH
FINES
SAND
AND
SANDY
SOILS (LITTLE OR NO FINES)
SANDS WITH
FINES
LIQUID LIMIT
LESS THAN 50
LIQUID LIMIT
GREATER THAN 50
HIGHLY ORGANIC SOILS
NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS
GRAVEL
AND
GRAVELLY
SOILS
(APPRECIABLE
AMOUNT OF FINES)
(APPRECIABLE
AMOUNT OF FINES)
(LITTLE OR NO FINES)
WELL-GRADED SANDS, GRAVELLY
SANDS, LITTLE OR NO FINES
CLEAN
GRAVELS
32
26
50/5"
3
2
2
FILL: Brown Silty fine to coarse Sand, some fine to coarse
Gravel, extensive Cobbles, medium dense-dry
ALLUVIUM: Brown Gravelly fine to coarse Sand, trace Silt,
medium dense to very dense-dry to damp
Boring Terminated at 7' due to refusal on dense Cobbles
JOB NO.: 20G250-2
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-1
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
I-1
SURFACE ELEVATION: 1614.5 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: ---
CAVE DEPTH: ---
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
5
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
2
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
29
26
50/5"
3
2
3
FILL: Brown Silty fine to coarse Sand, some fine to coarse
Gravel, extensive Cobbles, medium dense-dry to damp
ALLUVIUM:Brown Gravelly fine to coarse Sand to fine to
coarse Sandy Gravel, trace Silt, medium dense to very
dense-dry to damp
Boring Terminated at 7' due to refusal on dense Cobbles
JOB NO.: 20G250-2
PROJECT: Proposed Warehouse
LOCATION: Fontana, California
PLATE B-2
BL
O
W
C
O
U
N
T
DESCRIPTION
BORING NO.
I-2
SURFACE ELEVATION: 1613.5 feet MSL DR
Y
D
E
N
S
I
T
Y
(P
C
F
)
DE
P
T
H
(
F
E
E
T
)
MO
I
S
T
U
R
E
CO
N
T
E
N
T
(
%
)
LI
Q
U
I
D
LI
M
I
T
PL
A
S
T
I
C
LI
M
I
T
SA
M
P
L
E
FIELD RESULTS
WATER DEPTH: ---
CAVE DEPTH: ---
READING TAKEN: At Completion
OR
G
A
N
I
C
CO
N
T
E
N
T
(
%
)
5
GR
A
P
H
I
C
L
O
G
PO
C
K
E
T
P
E
N
.
(T
S
F
)
DRILLING DATE: 1/15/21
DRILLING METHOD: Hollow Stem Auger
LOGGED BY: Jose Zuniga
LABORATORY RESULTS
CO
M
M
E
N
T
S
PA
S
S
I
N
G
#2
0
0
S
I
E
V
E
(
%
)
TEST BORING LOG
TB
L
2
0
G
2
5
0
-
2
.
G
P
J
S
O
C
A
L
G
E
O
.
G
D
T
2
/
5
/
2
1
INFILTRATION CALCULATIONS
Project Name
Project Location
Project Number
Engineer
Test Hole Radius 4 (in)
Test Depth 7 (ft)
Infiltration Test Hole I-I
In
t
e
r
v
a
l
Nu
m
b
e
r
Ti
m
e
Ti
m
e
In
t
e
r
v
a
l
(m
i
n
)
Wa
t
e
r
De
p
t
h
(
f
t
)
Ch
a
n
g
e
i
n
Wa
t
e
r
Le
v
e
l
(
f
t
)
Av
e
r
a
g
e
He
a
d
He
i
g
h
t
(
f
t
)
In
f
i
l
t
r
a
t
i
o
n
Ra
t
e
Q
(i
n
/
h
r
)
Initial 10:05 AM 5.00
Final 10:08 AM 5.50
Initial 10:10 AM 5.00
Final 10:13 AM 5.50
Initial 10:16 AM 5.00
Final 10:26 AM 6.15
Initial 10:28 AM 5.00
Final 10:38 AM 6.15
Initial 10:40 AM 5.00
Final 10:50 AM 6.15
Initial 10:52 AM 5.00
Final 11:02 AM 6.12
Initial 11:04 AM 5.00
Final 11:14 AM 6.16
Initial 11:16 AM 5.00
Final 11:26 AM 6.14
Per County Standards, Infiltration Rate calculated as follows:
Where: Q = Infiltration Rate (in inches per hour)
∆H =Change in Height (Water Level) over the time interval
r = Test Hole (Borehole) Radius
∆t =Time Interval
Havg = Average Head Height over the time interval
3.5 0.50 1.75 8.94
1 10.0 1.15 1.43 8.67
PS2
Proposed Warehouse
Fontana, California
20G250-2
Joseph Lozano Leon
PS1
3 10.0 1.15 1.43 8.67
3.6 0.50 1.75 8.74
5 10.0 1.16 1.42 8.77
2 10.0 1.15 1.43 8.67
4 10.0 1.12 1.44 8.37
6 10.0 1.14 1.43 8.57
)2Ht(r
H(60r)Q
avg
INFILTRATION CALCULATIONS
Project Name
Project Location
Project Number
Engineer
Test Hole Radius 4 (in)
Test Depth 7 (ft)
Infiltration Test Hole I-2
In
t
e
r
v
a
l
Nu
m
b
e
r
Ti
m
e
Ti
m
e
In
t
e
r
v
a
l
(m
i
n
)
Wa
t
e
r
De
p
t
h
(
f
t
)
Ch
a
n
g
e
i
n
Wa
t
e
r
Le
v
e
l
(
f
t
)
Av
e
r
a
g
e
He
a
d
He
i
g
h
t
(
f
t
)
In
f
i
l
t
r
a
t
i
o
n
Ra
t
e
Q
(i
n
/
h
r
)
Initial 11:45 AM 4.85
Final 11:46 AM 5.35
Initial 11:49 AM 5.05
Final 11:51 AM 5.55
Initial 11:53 AM 4.90
Final 11:58 AM 6.01
Initial 12:00 PM 5.00
Final 12:05 PM 6.01
Initial 12:07 PM 5.00
Final 12:12 PM 6.03
Initial 12:14 PM 5.00
Final 12:19 PM 6.02
Initial 12:21 PM 5.00
Final 12:26 PM 6.04
Initial 12:28 PM 5.00
Final 12:33 PM 6.02
Initial 12:35 PM 5.00
Final 12:40 PM 6.01
Per County Standards, Infiltration Rate calculated as follows:
Where: Q = Infiltration Rate (in inches per hour)
∆H =Change in Height (Water Level) over the time interval
r = Test Hole (Borehole) Radius
∆t =Time Interval
Havg = Average Head Height over the time interval
1.8 0.50 1.90 16.59
1 5.0 1.11 1.55 15.56
PS2
Proposed Warehouse
Fontana, California
20G250-2
Joseph Lozano Leon
PS1
3 5.0 1.03 1.49 14.97
2.0 0.50 1.70 16.07
5 5.0 1.04 1.48 15.16
2 5.0 1.01 1.50 14.59
7 5.0 1.01 1.50 14.59
4 5.0 1.02 1.49 14.78
6 5.0 1.02 1.49 14.78
)2Ht(r
H(60r)Q
avg
Sample Description I-1 @ 6'
Soil Classification Brown Gravelly fine to coarse Sand, trace Silt
Proposed Warehouse
Fontana, California
Project No. 20G250-2
PLATE C-1
0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110100
Pe
r
c
e
n
t
P
a
s
s
i
n
g
b
y
W
e
i
g
h
t
Grain Size in Millimeters
Grain Size Distribution
Sieve Analysis Hydrometer Analysis
US Standard Sieve Sizes
Coarse Gravel Fine Gravel Crs. Sand Med. Sand Fine Sand Fines (Silt and Clay)
2 1 3/4 1/2 3/8 1/4 #4 #8 #10 #16 #20 #30 #40 #50 #100 #200
Sample Description I-2 @ 6'
Soil Classification Brown Gravelly fine to coarse Sand to fine to coarse Sandy Gravel, trace Silt
Proposed Warehouse
Fontana, California
Project No. 20G250-2
PLATE C-2
0
10
20
30
40
50
60
70
80
90
100
0.0010.010.1110100
Pe
r
c
e
n
t
P
a
s
s
i
n
g
b
y
W
e
i
g
h
t
Grain Size in Millimeters
Grain Size Distribution
Sieve Analysis Hydrometer Analysis
US Standard Sieve Sizes
Coarse Gravel Fine Gravel Crs. Sand Med. Sand Fine Sand Fines (Silt and Clay)
2 1 3/4 1/2 3/8 1/4 #4 #8 #10 #16 #20 #30 #40 #50 #100 #200
REDLANDS, CALIFORNIA
301 9th St., Suite 114
Redlands, CA 92374
T: 909.254.4035
F: 602.254.6280
info@paleowest.com
Paleontological Resource Assessment for the Sierra Distribution Facility Project,
City of Fontana, San Bernardino County, California | 1
September 15, 2022
Candyce Burnett
Kimley-Horn
3880 Lemon Street, Suite 420
Riverside, California 92501
Transmitted via email to Candyce.Burnett@kimley-horn.com
RE: Paleontological Resource Assessment for the Sierra Distribution Facility Project, City of
Fontana, San Bernardino County, California
Dear Candyce Burnett,
At the request of Kimley-Horn, PaleoWest, LLC (PaleoWest) conducted a paleontological
resource assessment for the Sierra Distribution Facility Project (Project) in the city of
Fontana, San Bernardino County, California.The goal of the assessment is to identify the
geologic units that may be impacted by development of the Project, determine the
paleontological sensitivity of geologic units within the Project area, assess potential for impacts
to paleontological resources from development of the Project, and recommend mitigation
measures to avoid or mitigate impacts to scientifically significant paleontological resources, as
necessary.
This paleontological resource assessment included a fossil locality records search conducted by
the San Bernardino County Museum (SBCM) in Redlands, California. The records search was
supplemented by a review of existing geologic maps and primary literature regarding
fossiliferous geologic units within the proposed Project vicinity and region. This technical
memorandum, which was written in accordance with the guidelines set forth by the Society of
Vertebrate Paleontology (SVP) (2010), has been prepared to support environmental review
under the California Environmental Quality Act (CEQA); the City of Fontana is the Lead Agency
for CEQA compliance.
PROJECT LOCATION AND DESCRIPTION
The proposed Project involves the development of a warehouse distribution facility and support
facilities in the city of Fontana, San Bernardino County, California (Figure 1). The proposed
Project would encompass approximately 18 acres of land (Assessor Parcel Number: 1119-241-
10, -13, -18, -25, -26, -27) at the northeast corner of the intersection of Sierra Avenue and
Clubhouse Drive in the northern portion of the city. As shown in Figure 2, the Project area is
within Section 29, Township 1 North, Range 5 West, San Bernardino Baseline and Meridian, as
depicted on the Devore, CA 7.5' U.S. Geological Survey (USGS) topographic quadrangle.
Paleontological Resource Assessment for the Sierra Distribution Facility Project,
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Figure 1. Project vicinity map.
Paleontological Resource Assessment for the Sierra Distribution Facility Project,
City of Fontana, San Bernardino County, California | 3
Figure 2. Project location map.
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City of Fontana, San Bernardino County, California | 4
REGULATORY CONTEXT
Paleontological resources (i.e., fossils) are considered nonrenewable scientific resources
because once destroyed, they cannot be replaced. As such, paleontological resources are
afforded protection under various federal, state, and local laws and regulations. Laws pertinent
to this Project are discussed below.
STATE LAWS AND REGULATIONS
California Environmental Quality Act
CEQA requires that public agencies and private interests identify the potential environmental
consequences of their projects on any object or site of significance to the scientific annals of
California (Division I, California Public Resources Code [PRC] Section 5020.1 [b]). Appendix G in
Section 15023 provides an Environmental Checklist of questions (PRC 15023, Appendix G,
Section VII, Part f) that includes the following: “Would the project directly or indirectly destroy a
unique paleontological resource or site or unique geological feature?”
CEQA does not define “a unique paleontological resource or site.” However, the SVP has
provided guidance specifically designed to support state and Federal environmental review. The
SVP broadly defines significant paleontological resources as follows (SVP, 2010:11):
“Fossils and fossiliferous deposits consisting of identifiable vertebrate fossils,
large or small, uncommon invertebrate, plant, and trace fossils, and other data
that provide taphonomic, taxonomic, phylogenetic, paleoecologic, stratigraphic,
and/or biochronologic information. Paleontological resources are considered to
be older than recorded human history and/or older than middle Holocene (i.e.,
older than about 5,000 radiocarbon years).”
Significant paleontological resources are determined to be fossils or assemblages of fossils that
are unique, unusual, rare, diagnostically important, or are common but have the potential to
provide valuable scientific information for evaluating evolutionary patterns and processes, or
which could improve our understanding of paleochronology, paleoecology,
paleophylogeography, or depositional histories. New or unique specimens can provide new
insights into evolutionary history; however, additional specimens of even well represented
lineages can be equally important for studying evolutionary pattern and process, evolutionary
rates, and paleophylogeography. Even unidentifiable material can provide useful data for dating
geologic units if radiometric dating is possible. As such, common fossils (especially vertebrates)
may be scientifically important, and therefore considered significant.
California Public Resources Code
Section 5097.5 of the Public Resources Code (PRC) states:
“No person shall knowingly and willfully excavate upon, or remove, destroy,
injure or deface any historic or prehistoric ruins, burial grounds, archaeological or
vertebrate paleontological site, including fossilized footprints, inscriptions made
by human agency, or any other archaeological, paleontological or historical
feature, situated on public lands, except with the express permission of the
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public agency having jurisdiction over such lands. Violation of this section is a
misdemeanor.”
As used in this PRC section, “public lands” means lands owned by, or under the jurisdiction of,
the state or any city, county, district, authority, or public corporation, or any agency thereof.
Consequently, public agencies are required to comply with PRC 5097.5 for their own activities,
including construction and maintenance, as well as for permit actions (e.g., encroachment
permits) undertaken by others.
LOCAL
The Final Environmental Impact Report for the City’s General Plan Update 2015-2035 (City of
Fontana, 2017) identifies two mitigation measures related to paleontological resources to be
implemented by the City. These include:
MM-CUL-4 A qualified paleontologist shall conduct a pre-construction field survey of any
project site within the Specific Plan Update area that is underlain by older alluvium.
The paleontologist shall submit a report of findings that provides specific
recommendations regarding further mitigation measures (i.e., paleontological
monitoring) that may be appropriate.
MM-CUL-5 Should mitigation monitoring of paleontological resources be recommended for a
specific project within the project site, the program shall include, but not be limited to, the
following measures:
Assign a paleontological monitor, trained and equipped to allow the rapid removal of
fossils with minimal construction delay, to the site full-time during the interval of
earth-disturbing activities.
Should fossils be found within an area being cleared or graded, earth-disturbing
activities shall be diverted elsewhere until the monitor has completed salvage. If
construction personnel make the discovery, the grading contractor shalt immediately
divert construction and notify the monitor of the find.
All recovered fossils shall be prepared, identified, and curated for documentation in
the summary report and transferred to an appropriate depository (i.e., San
Bernardino County Museum).
A summary report shall be submitted to City of Fontana. Collected specimens shall
be transferred with copy of report to San Bernardino County Museum.
PALEONTOLOGICAL RESOURCE POTENTIAL
Absent specific agency guidelines, most professional paleontologists in California adhere to the
guidelines set forth by SVP (2010) to determine the course of paleontological mitigation for a
given project. These guidelines establish protocols for the assessment of the paleontological
resource potential of underlying geologic units and outline measures to mitigate adverse
impacts that could result from project development. Using baseline information gathered during
a paleontological resource assessment, the paleontological resource potential of the geologic
unit(s) (or members thereof) underlying a project area can be assigned to one of four categories
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defined by SVP (2010). Although these standards were written specifically to protect vertebrate
paleontological resources, all fields of paleontology have adopted the following guidelines:
HIGH POTENTIAL (SENSITIVITY)
Rock units from which significant vertebrate or significant invertebrate fossils or significant
suites of plant fossils have been recovered have a high potential for containing significant non-
renewable fossiliferous resources. These units include but are not limited to, sedimentary
formations and some volcanic formations which contain significant nonrenewable.
LOW POTENTIAL (SENSITIVITY)
Sedimentary rock units that are potentially fossiliferous but have not yielded fossils in the past
or contain common and/or widespread invertebrate fossils of well documented and understood
taphonomic, phylogenetic species and habitat ecology. Reports in the paleontological literature
or field surveys by a qualified vertebrate paleontologist may allow determination that some
areas or units have low potentials for yielding significant fossils prior to the start of
construction. Generally, these units will be poorly represented by specimens in institutional
collections and will not require protection or salvage operations. However, as excavation for
construction gets underway it is possible that significant and unanticipated paleontological
resources might be encountered and require a change of classification from Low to High
Potential and, thus, require monitoring and mitigation if the resources are found to be
significant.
UNDETERMINED POTENTIAL (SENSITIVITY)
Specific areas underlain by sedimentary rock units for which little information is available have
undetermined fossiliferous potentials. Field surveys by a qualified vertebrate paleontologist to
specifically determine the potentials of the rock units are required before programs of impact
mitigation for such areas may be developed.
NO POTENTIAL
Rock units of metamorphic or igneous origin are commonly classified as having no potential for
containing significant paleontological resources.
METHODS
To assess whether or not a particular area has the potential to contain significant fossil
resources at the subsurface, it is necessary to review published geologic mapping to determine
the geology and stratigraphy of the area. Geologic units are considered to be “sensitive” for
paleontological resources if they are known to contain significant fossils anywhere in their
extent. Therefore, a search of pertinent local and regional museum repositories for
paleontological localities within and nearby the project area is necessary to determine whether
fossil localities have been previously discovered within a particular rock unit. For this Project, a
formal museum records search was conducted at the SBCM, and informal records searches
were conducted of the online University of California Museum of Paleontology Collections
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(UCMP) and other published and unpublished geological and paleontological literature of the
area.
RESOURCE CONTEXT
GEOLOGIC SETTING
The Project area is south of the foothills of the San Gabriel Mountains, which are part of the
Transverse Ranges geomorphic province of Southern California. The San Gabriel Mountains
extend approximately 60 miles (mi) west to the Verdugo Hills, San Fernando Valley, and
Soledad Basin. Active uplift and erosion in the San Gabriel Mountains have produced steep
canyons, rugged topography, numerous landslides, and extensive alluvial sedimentation
(Morton and Miller, 2006). Late Cenozoic uplift of the San Gabriel Mountains is largely due to
vertical slip along several influential faults, including the Sierra Madre Fault Zone just south of
the Project area. The highest peak in the San Gabriel Mountains is Mount San Antonio (Old
Baldy) at 10,080 feet (ft), and much of the range displays large relief with deep narrow canyons
and peaks above 7000 ft (Norris and Webb, 1976). The San Gabriel Mountains are
predominantly crystalline and consist of Proterozoic to Mesozoic intrusive igneous (plutonic)
and metamorphic rocks as well as Cenozoic volcanic, marine, and terrestrial sedimentary
deposits, including extensive alluvial fan and terrace deposits (Morton et al., 2003). The Project
area is underlain by Quaternary alluvial fan deposits eroded from the San Gabriel Mountains to
the north.
SITE SPECIFIC GEOLOGY AND PALEONTOLOGY
According to Morton and Matti (2001), the Project area is underlain by alluvial fan deposits
(Qyf5) from the Holocene Epoch. The source material for these alluvial fan deposits originates
from the eastern San Gabriel Mountains, north of the Project area. The young alluvial fan
deposits consist of unconsolidated to moderately consolidated, boulder to coarse-grained sand,
with slightly dissected surfaces. The Holocene alluvium likely grades into older high sensitivity
Pleistocene deposits at depth. Pleistocene deposits in San Bernardino County are highly
fossiliferous and have yielded preserved remains of deer, mammoth, camel, horse, bison,
badger, mole, rabbit, gray fox, and coyote (Jefferson, 1991a, 1991b; Miller, 1971). However,
fossil localities have not been identified in the immediate vicinity of the Project area.
RECORDS SEARCH RESULTS
The SBCM records search did not produce any fossil localities from within the Project area or
from the same geologic unit within 5 mi (Kottkamp, 2022). Searches of online databases and
other literature did not produce any additional fossil localities within 1 mi.
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Figure 3. Geologic map.
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City of Fontana, San Bernardino County, California | 9
FINDINGS
This memorandum uses the classification system of SVP (2010) to assess paleontological
sensitivity and the level of effort required to manage potential impacts to significant fossil
resources. Using this system, the sensitivity of geologic units was determined on the basis of
the relative abundance and risk of adverse impacts to vertebrate fossils and significant
invertebrates and plants.
Young alluvial-fan deposits mapped in the Project area are Holocene-age at the surface but may
transition into Pleistocene-age deposits with depth. According to SVP (2010), the Holocene-age
deposits have a low paleontological sensitivity, but the deeper Pleistocene-age sediments
would have a high sensitivity. However, the absence of nearby Pleistocene localities suggests
the Holocene sediments in the Project area extend to a significant depth, and Pleistocene
sediments are unlikely to be encountered through routine ground disturbance. Consequently,
Project related ground disturbance is unlikely to impact paleontological resources.
RECOMMENDATIONS
In general, the potential for a given project to result in negative impacts to paleontological
resources is directly proportional to the amount of ground disturbance associated with the
project; thus, the higher the amount of ground disturbances within geological deposits with a
known paleontological sensitivity, the greater the potential for negative impacts to
paleontological resources. Since this Project entails the excavation for a building, new ground
disturbances are anticipated; however, the underlying sediment is likely to be Holocene in age
to a significant depth, and ground disturbances are not anticipated to impact paleontological
resources. PaleoWest does not recommend paleontological monitoring for this Project.
Thank you for contacting PaleoWest for this Project. If you have any questions, please do not
hesitate to contact us.
Sincerely,
PALEOWEST
Heather Clifford, M.S. | Senior Paleontologist
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REFERENCES
City of Fontana, 2017, General Plan Update 2015–2035. Accessed August 18, 2022 at
https://www.fontana.org/DocumentCenter/View/28271/Complete-Document---
Approved-General-Plan-Documents-11-13-2018
Jefferson, G.T., 1991a, A catalogue of Late Quaternary vertebrates from California: part one.
Non-marine lower vertebrate and avian taxa: Natural History Museum of Los Angeles
County Technical Reports, Number 5.
Jefferson, G.T., 1991b, A catalogue of Late Quaternary vertebrates from California: part two.
Mammals: Natural History Museum of Los Angeles County Technical Reports, Number
7.
Kottkamp, S., 2022, Unpublished museum records search of the SBCM.
Miller, W.E., 1971, Pleistocene Vertebrates of the Los Angeles Basin and Vicinity (exclusive of
Rancho La Brea). Bulletin of the Natural History Museum of Los Angeles County,
Science, Number 10, 121 pp.
Morton, D.M., J.C. Matti, G. Morton, C. Koukladas, and P.M. Cossette, 2001, Geologic map of
the Devore 7.5' quadrangle, San Bernardino County, California, U.S. Geological Survey,
Open-File Report OF-2001-173, 1:24,000.
Morton, D.M., and F.K. Miller, 2006, Geologic map of the San Bernardino and Santa Ana 30' x
60' quadrangles, California: U.S. Geological Survey, Open-File Report OF-2006-1217,
scale 1:100,000.
Morton, D.M., F.K. Miller, P.M. Cossette, and K.R. Bovard, 2003, Preliminary geologic map of
the San Bernardino 30' X 60' quadrangle, California: U.S. Geological Survey, Open-File
Report OF-2003-293, scale 1:100,000.
Norris, R.M., and R.W. Webb, 1976, Geology of California. John Wiley & Sons, New York.
Society of Vertebrate Paleontology (SVP), 2010, Standard Procedures for the Assessment and
Mitigation of Adverse Impacts to Paleontological Resources Society of Vertebrate
Paleontology. Impact Mitigation Guidelines Revision Committee. Pages 1–11.
Bethesda, MD.