HomeMy WebLinkAboutTract Map 1-44 Parcel 39 Preliminary Geotechnical Report Singh Residence1
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1 PRELIMINARY GEOTECHNICAL
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INTERPRETIVE REPORT
PROPOSED SINGH RESIDENCE
ASSESSOR'S PARCEL NUMBER 957-090-0019-0
1 31250 NICOLAS ROAD, CITY OF TEMECULA
RIVERSIDE COUNTY, CALIFORNIA
1 PROJECT NO. 16585-10
ISSUED: JANUARY 25, 2017
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CW SOILS
i 23251 Kent Court
Murrieta. CA 92562
951-304-3935
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cwsoils.coan
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January 25, 2017 Project No. 16585-10
Sohan and Kuldip Singh
31250 Nicolas Road
Temecula, CA 92591
Subject: Preliminary Geotechnical Interpretive Report, Proposed Singh Residence, Assessor's
Parcel Number 957-090-0019-0, 31250 Nicolas Road, City of Temecula, Riverside County,
California
In accordance with your request, CW Soils is pleased to present our preliminary geotechnical interpretive report
for the proposed Singh Residence, Assessor's Parcel Number 957-090-0019-0, located at 31250 Nicolas Road
in the City of Temecula, Riverside County, California. Our services were completed in accordance with the
scope of work described in our proposal, dated December 9, 2016. The purpose of our work was to evaluate the
nature, distribution, and engineering properties of the geologic formations underlying the site with respect to the
proposed improvements.
CW Soils appreciates the opportunity to offer our services on this project. If we can be of further assistance,
please do not hesitate to contact the undersigned at your convenience.
Respectfully submitted,
CW Soils
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CW SOILS, -3251 Kent Court. Murrieta, CA 92562 - 951-304-3935 cwsoils.com
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TABLE OF CONTENTS
INTRODUCTION ........................................................................................................................................... I
SITEDESCRIPTION...................................................................................................................................... 1
PROPOSED DEVELOPMENT.................................................................................................................. I
FIELD EXPLORATION AND LABORATORY TESTING......................................................................... 3
Field Exploration ......................................................................................................................................... 3
LaboratoryTesting...................................................................................................................................... 3
FINDINGS ....................................................................................................................................................... 3
RegionalGeology ......................................................................................................................................... 3
LocalGeology............................................................................................................................................... 4
GeologicStructure....................................................................................................................................... 4
AerialPhotographs...................................................................................................................................... 4
Faulting........................................................................................................................................................ 4
CONCLUSIONS AND RECOMMENDATIONS .......................................................................................... 6
General......................................................................................................................................................... 6
Earthwork.................................................................................................................................................... 6
GradingOperations ................................................................................................................................. 6
Clearingand Grubbing............................................................................................................................ 6
Excavation Characteristics...................................................................................................................... 6
Groundwater............................................................................................................................................ 6
Ground Preparation ................................................................................................................................ 6
OversizeRock .......................................................................................................................................... 7
CompactedFill Placement....................................................................................................................... 7
Import Soils.............................................................................................................................................. 7
FillSlopes ................................................................................................................................................. 7
TemporaryBackeuts................................................................................................................................ 7
Shrinkage, Bulking, and Subsidence....................................................................................................... 7
GeotechnicalObservations ...................................................................................................................... 8
PostGrading Considerations....................................................................................................................... 8
Slope Landscaping and Maintenance...................................................................................................... 8
SiteDrainage............................................................................................................................................ 8
UtilityTrenches........................................................................................................................................ 8
SEISMIC DESIGN PARAMETERS.............................................................................................................. 9
GroundMotions........................................................................................................................................... 9
Secondary Seismic Hazards....................................................................................................................... 10
Liquefaction and Lateral Spreading......................................................................................................... 10
GroundSubsidence.................................................................................................................................... 10
PRELIMINARY FOUNDATION DESIGN RECOMMENDATIONS....................................................... 1 1
General....................................................................................................................................................... I I
AllowableBearing Values.......................................................................................................................... I 1
Settlement................................................................................................................................................... I 1
LateralResistance...................................................................................................................................... 1 I
Expansive Soil Considerations ......._................._...................................................................................... 11
Low Expansion Potential (Expansion Index of 21 to 50).......................................................................... 12
Conventional Footings ........................................................................................................................... 12
BuildingFloor Slabs............................................................................................................................... 12
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Post Tensioned Slab/Foundation Design Recommendations.................................................................... 13
Structural Setbacks and Building Clearance............................................................................................ 14
FoundationObservations .......................................................................................................................... 14
Corrosivity .......... .................................................. 15
RETAININGWALLS................................................................................................................................... 16
Active and At-Rest Earth Pressures.......................................................................................................... 16
SubdrainSystem........................................................................................................................................ 16
TemporaryExcavations............................................................................................................................. 17
Retaining Wall Backfill ............................................................................................................................. 17
EXTERIORCONCRETE............................................................................................................................. 17
SubgradePreparation................................................................................................................................ 17
Flatwork Design......................................................................................................................................... 17
GRADING PLAN REVIEW AND CONSTRUCTION SERVICES........................................................... 18
REPORTLIMITATIONS............................................................................................................................. 18
Attachments:
Figure 1 —Vicinity Map
Figure 2—Regional Geologic Map
APPENDIX A—References
APPENDIX B—Field Exploration
APPENDIX C—Laboratory Analysis
APPENDIX D— Seismic Design Criteria
APPENDIX E —General Earthwork and Grading Specifications
Plate 1 —Geotechnical Map
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CW SOILS,23251 Kent Court. Murrieta. CA 92562 951-304-3935 - cwsoils.com
INTRODUCTION
This report prepared by CW Soils, presents the preliminary interpretive geotechnical evaluation for the
proposed improvements. The purpose of our work was to evaluate the nature, distribution, and engineering
properties of the geologic formations underlying the site with respect to the proposed improvements.
Furthermore, we have included grading and foundation design recommendations based on the information you
provided.
SITE DESCRIPTION
The site is located at 31250 Nicolas Road in the City of Temecula, Riverside County, California. The subject
property is surrounded by scattered residential developments. The general location of the subject property is
illustrated on Figure 1 —Vicinity Map.
The subject property consists of about 4.03 acres of partially developed land with relatively flat terrain.
Topographic relief at the subject property is relatively low.
Vegetation at the site includes sparse to moderate amounts of annual weeds/grasses, along with some scattered
small trees. No readily apparent indications of past grading operations were observed within the proposed
project area.
PROPOSED DEVELOPMENT
Based on our understanding of the proposed project, one building positioned in the northern region of the site is
planned. The proposed residential development is anticipated to consist of wood, concrete, or steel framed one-
and/or two-story structures utilizing slab on grade construction with associated driveway, landscape areas, and
utilities. The proposed development plans call for fill slopes on the order of 5 feet high.
Formal plans have not been prepared and await the conclusions and recommendations of this report.
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FIELD EXPLORATION AND LABORATORY TESTING
Field Exploration
Subsurface exploration at the subject property was performed on January 6. 2017. A backhoe was mobilized to
excavate two test pits throughout the project area to a maximum depth of 7 feet.
Classification and logging of the soils encountered during the field exploration were performed in general
accordance with the Standard Practice for Description and Identification of Soils (Visual-Manual Procedure) of
ASTM D 2488. Earth material descriptions may have been reconciled to reflect laboratory test results with
regard to ASTM D 2487 or re-examination in the laboratory. Descriptive logs and the Log Symbols & Terms
explanation sheet are presented in Appendix B.
Associated with the subsurface exploration was the collection of disturbed bulk samples and/or relatively
undisturbed samples of soils for laboratory testing and analysis. The samples were placed in sealed containers
and transported to the laboratory for testing and analysis. The exploratory locations and geologic conditions at
the subject property are illustrated on Plate 1 —Geotechnical Map.
Laboratory Testing
Maximum dry density/optimum moisture content, expansion potential, pH, resistivity, sulfate content, and
chloride content were determined for selected samples of soils, considered representative of those noted during
the field exploration. The laboratory test results are reflected throughout the Conclusions and
Recommendations of this report. Summaries of the test results and brief descriptions of laboratory test criteria
are presented in Appendix C.
FINDINGS
Regional Geology
Regionally, the project is located in the Peninsular Ranges Geomorphic Province of California. The Peninsular
Ranges are characterized by northwest trending sediment filled elongated valleys divided by steep mountain
ranges. Associated with and subparallel to the northwest trending San Andreas Fault, are the San Jacinto Fault,
Newport-Inglewood Fault, and the Whittier-Elsinore Fault zones. The northwest trend of the province has
played a major role in shaping the dominant structural geologic features in the region as well. The Perris Block
forms the eastern boundary of the Elsinore Fault, while the west side is comprised of the Santa Ana Mountains.
The Perris Block is in turn bounded to the east by the San Jacinto Fault. The Peninsular Ranges Province and
the Transverse Range Province are separated by the northern perimeter of the Los Angeles basin, which is
formed by a northerly dipping blind thrust fault.
The low lying areas within the Peninsular Ranges Province are principally made up of Tertiary and Quaternary
non-marine alluvial sediments consisting of alluvial deposits, sandstones, claystones, siltstones, conglomerates,
and occasional volcanic units. The mountainous regions are primarily made up of Pre-Cretaceous,
metasedimentary, and metavolcanic rocks along with Cretaceous plutonic rocks of the Southern California
Batholith. A map illustrating the regional geology is presented on Figure 2 — Regional Geologic Map.
Jan uory25, 2017 3 CW Soils
Local Geology
The most relevant local geologic units expected to be present at the site are summarized in this section. A
general description of the dominant soils that form the geologic units is provided below:
Quaternary Young Alluvial Deposits (map symbol Qya): Quaternary young alluvial deposits were
encountered directly from the surface to a maximum depth of 4 feet. These young alluvial deposits
consist predominately of medium brown, fine to coarse grained silty sand. These deposits were
generally noted to be in a moist to very moist, loose state.
Quaternary Pauba Formation (map symbol Qps): Pauba Formation bedrock was generally encountered
below the alluvial materials to the full depth of our exploration. These materials primarily consisted of
light brown, fine to coarse grained sandstone with varying amounts of silt. These materials were
generally noted to be slightly moist to moist, moderately hard to hard and poorly bedded. Typically, the
Lipper 1 to 3 feet of this unit is slightly more weathered and not as hard with occasional lenses of less
indurated rock.
Geologic Structure
The bedrock described is common to this area. The sandstone bedrock is generally massive and lacks
significant structural planes.
Aerial Photographs
A review of aerial photographs was performed during our geotechnical evaluation. No strong geomorphic
expressions suggestive of recent faulting, such as linear topography, offset streams/drainage courses, lines of
natural springs, or fault scarps, were interpreted to project through the proposed project area during our review
of the aerial photographs of the subject property. While conducting our interpretive analysis of the site, no
geomorphic evidence of recently active landsliding was found. Aerial photographs from different time periods
and various scales that were utilized in our geomorphic interpretations include the following from Google Earth
dated September 29, 1996. May 21, 2002, December 30, 2005, November IL 2009, June 7, 2012, and February
9, 2016.
Faulting
Significant ground shaking will likely impact the site within the design life of the proposed project, due to the
project being located in a seismically active region. The geologic structure of the entire southern California
area is dominated by northwest-trending faults associated with the San Andreas Fault system The San Andreas
Fault system accommodates for most of the right lateral movement associated with the relative motion between
the Pacific and North American tectonic plates. The subject property is not located within an Alquist-Priolo
Fault Rupture Hazard Study Zone, established by the State of California to restrict the construction of habitable
structures across identifiable traces of known active faults. No active faults are known to project through the
proposed project. As defined by the State of California, an active fault has undergone surface displacement
within the past 11.000 years or during the Holocene geologic time period. Based upon our understanding of the
site and our analysis using the referenced software (USGS 2002 Interactive Deaggregation), the Elsinore Fault
with an approximate source to site distance of 7.2 kilometers is the closest known active fault anticipated to
produce the highest ground accelerations, having an estimated maximum modal magnitude of 6.76. The
potential for surface rupture to adversely impact the safety of the proposed structures inhabitants is very low to
remote.
January 25, 2017 4 CW soils
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1 Reference: Morton, D.M., Hauser, Rachel M.,and Ruppert, Kelly R., 2004, Preliminary Digital Geologic Map o(the Santa Ana
30'x 60'Quadrangle,Southern California, Version 2.0: U.S. Geological Survey Open-File Report 99-0172
i 16585-10
REGIONAL GEOLOGIC MAP Not to Scale
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Remedial grading should extend horizontally beyond the perimeter of the proposed structures a distance
equal to the depth of compacted fill below the proposed footing or a minimum of 5 feet, whichever is
greater. The anticipated removal depths are shown on Plate I — Geotechnical Map. In general the
anticipated removal depths should vary from 3 to 5 feet below existing grade.
Oversize Rock
Minor quantities of oversize rock (i.e., rock exceeding a maximum dimension of 12 inches) is expected
to be encountered during grading. Oversize rock that is encountered should be disposed of offsite,
t dispersed throughout the site at the surface of natural grades, or stockpiled and crushed for future use.
The disposal of oversize rock is discussed in greater detail in the last appendix of this report, General
Earthwork and Grading Specifications.
Compacted Fill Placement
Well mixed soils should be placed in 6 to 8 inch maximum (uncompacted) lifts, watered or air dried as
necessary to achieve uniform near optimum moisture content and then compacted to a minimum of 90
percent of the maximum dry density as determined by ASTM D1557-12.
Import Soils
If needed to achieve final design grades, all potential import materials should be non-expansive, free of
deleterious/oversize materials, and approved by the project soils engineering consultant prior to delivery
onsite.
Fill Slopes
Fill slopes higher than 5 feet and steeper than 5:1 (h:v) require a keyway at the toe. Keyways should be
excavated 2 feet into competent earth materials, as measured on the downhill side and be a minimum of
10 feet wide. Backcuts for keyway excavations should be cut no steeper than 1:1 or as recommended by
the soils engineer or engineering geologist.
Temporary Backcuts
With regard to excavation safety, it is the responsibility of the grading contractor to follow all Cal-
OSHA requirements. Adequate slope stability to protect adjacent developments must be maintained,
temporary backcuts for canyon removals, stabilization fills, and/or keyways may be needed. It is
imperative that grading schedules minimize the exposure time of the unsupported excavations.
Temporary backcuts should be observed by the engineering geologist or his representative during
grading/construction operations.
Shrinkage, Bulking, and Subsidence
IVolumetric reductions in soils will occur as poorly consolidated soils are replaced with properly
compacted fill. The estimates of shrinkage/bulking and subsidence are intended as an aid for project
engineers in determining earthwork quantities. Since many variables can affect the accuracy of these
estimates, they should be used with caution and contingency plans should he in place for balancing the
project. Subsidence resulting from scarification and recompaction of bottom excavations is expected to
be negligible to approximately 0.01 foot.
January 25, 2017 7 CW Soils
CONCLUSIONS AND RECOMMENDATIONS
General
From a geotechnical point of view, the subject property is considered suitable for the proposed improvements,
provided the design information and conclusions and recommendations herein are incorporated into the plans
r; and are implemented during construction.
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Earthwork
Grading Operations
Grading operations are subject to the provisions of the 2013 California Building Code (CBC), including
Appendix J Grading, as well as all applicable grading codes and requirements of the appropriate
reviewing agency. Grading operations should also be conducted in accordance with applicable
requirements of our General Earthwork and Grading Specifications within the final appendix of this
report, unless more conservative recommendations are provided herein.
I 'Clearing and Grubbing
Areas undergoing grading operations should be stripped of vegetation including trees, grasses, weeds,
I 'brush, shrubs, or any other debris and properly disposed of offsite. Laborers should be employed to
remove roots, branches, or other deleterious materials during grading operations.
CW Soils should be notified in a timely manner in order to provide observations during Clearing and
Grubbing operations. Any buried foundations or unanticipated conditions should be brought to our
immediate attention to consider whether adjustments are necessary.
Excavation Characteristics
Based on our experience with similar projects in similar settings, the near surface soils, will be readily
excavated with conventional earth moving equipment appropriately selected for the task to be
performed.
Groundwater
t Groundwater was not observed during the field exploration conducted to a maximum depth of 7 feet in
Test Pit 1.
Ground Preparation
In areas to receive compacted fill, the removal of low density, compressible soils, such as topsoil,
alluvial materials, and any undocumented artificial fill, should continue until firm competent bedrock is
encountered. Removal excavations should be verified by the project engineer, geologist or their
representative. Prior to placing compacted fills, the exposed bottom should be scarified to a depth of 6
inches or more, watered or air dried as necessary to achieve near optimum moisture content and then
compacted to a minimum of 90 percent of the maximum dry density as determined by ASTM D 1557-12.
January 25, 2017 6 CW Soils
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Shrinkage/bulking estimates for the various geologic units that are expected to undergo volume changes
during grading operations are provided below.
GEOLOGIC UNIT SHRINKAGE I%)
Alluvium 15 to 20
Bedrock 5 to 10
Geotechnical Observations
Clearing operations, removal of unsuitable materials, and general grading procedures should be
observed by the project soils consultant or his representative. Compacted fill should not be placed
without prior bottom observations being conducted by the soils consultant or his representative to verify
the adequacy of the removals.
The project soils consultant or his representative should be present to observe grading operations and to
check that the minimum compaction requirements are being obtained. In addition, verification of
compliance with the other grading recommendations presented herein should be provided concurrently.
Post Grading Considerations
Slope Landscaping and Maintenance
Provided all drainage provisions are properly constructed and maintained, the gross stability of graded
slopes should not be adversely affected. However, satisfactory slope and building pad drainage is
essential for the long term performance of the site. Concentrated drainage should not be allowed to Flow
uncontrolled over any descending slope. As recommended by the project landscape architect,
engineered slopes should be landscaped with deep rooted, drought tolerant maintenance free plant
species.
Site Drainage
Maintaining control over drainage throughout the site is important for the long term performance of the
proposed improvements. We recommend roof gutters or equivalent roof collection system for proposed
structures. Pad and roof drainage should be routed in non-erosive drainage devices to driveways.
adjacent streets, storm-drain facilities, or other locations approved by the building official. Drainage
should not be allowed to pond on the building pad or near any foundations. Planters located within
retaining wall backfill should be sealed to prevent moisture intrusion into the backfill. Planters located
next to structures should be sealed to the depth of the footings. Drainage control devices require
periodic cleaning, testing and maintenance to remain effective.
Building pad drainage should be designed to meet the minimum gradient requirements of the CBC, to
divert water away fi•om foundations.
Utility Trenches
All utility trench backfill should be compacted at near optimum moisture to a minimum of 90 percent of
the maximum dry density as determined by ASTM D1557-12. Trench backfill should be placed in
anuary25, 2017 8 CW Soils
approximately 6 to 8 inch maximum loose lifts and then mechanically compacted with a hydro-hammer,
a sheepsfoot, pneumatic tampers, or similar equipment. Within pavement areas, the upper 6 inches of
subgrade materials for utility trench backfill should be compacted to 95 percent of the maximum dry
density determined by ASTM D1557-12. The utility trench backfill should be observed and tested by
the project soils engineer or their representative to verify that the minimum compaction requirements
have been obtained.
Where utility trenches undercut perimeter foundations, all utility trenches should be backfilled with
compacted fill, lean concrete, or concrete sherry. When practical, interior or exterior utility trenches that
run parallel to structure footings should not be located within a 1:1 (h:v) plane projected downward ftom
the outside bottom edge of the footing.
SEISMIC DESIGN PARAMETERS
Ground Motions
To resist the effects of design level seismic ground motions in order to prevent collapse (1% probability of
collapse in 50 years), structures are required to be designed and constructed in accordance with the 2013
California Building Code Section 1613. The design is reliant on the site class, risk category (L II, 111, or IV),
and mapped spectral accelerations for short periods (Ss) and a 1-second period (S1).
Based on data and maps jointly compiled by the United-States Geological Survey (USGS) and the California
Geological Survey (CGS), spectral accelerations for the subject property were generated via a software
application provided by the USGS website, Earthquake Hazards Program. The data summarized in the
following table is based on the Maximum Considered Earthquake Geometric Mean (MCEo) with 5% damped
ground motions having a 2% probability of being exceeded in 50 years (2,475 year return period).
The seismic design parameters were determined by a combination of the site class, mapped spectral
accelerations, on site soil/rock conditions, and risk category. The compilation of seismic design parameters
found below are considered appropriate for implementation during structural design. The USGS Design
Summary Report is included in Appendix D.
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PARAMETER FACTOR
Site Location
Latitude: 33.545
Longitude:itude: -117.1128
Site Class (1613.3.2 of2013 CBC, Chapter 20 ofASCE 7) D
Mapped Spectral Accelerations for short periods SS(g) 1.773
Mapped Spectral Accelerations for 1-Second Period S1 (g) 0.699
Maximum Considered Earthquake Spectral Response
sill,(g) 1.773
Acceleration for Short Periods
Maximum Considered Earthquake Spectral Response
Smi (g) 1.047
Acceleration for 1-Second Period
Design Spectral Response Acceleration for Short Periods Sos(g) 1.182
Design Spectral Response Acceleration for 1-Second Period Sni (9) 0.698
Seismic Design Category D
Importance Factor Based on Occupancy Category II
Januory25, 2017 9 CWSoils
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A probabilistic seismic hazard assessment for the site was conducted in accordance with the 2013 CBC, Section
1803.5.12, The probabilistic seismic hazard maps and data files were jointly prepared by the United States
Geological Survey (USGS) and the California Geological Survey (CGS). Actual ground shaking intensities at
the subject property may be substantially higher or lower based on complex variables such as the near source
directivity effects, depth and consistency of soils, topography, geologic structure, direction of fault rupture,
seismic wave reflection, refraction, and attenuation rates. The estimated probabilistic peak ground acceleration
at the site is, PGA= 0.677.
Secondary Seismic Hazards
Secondary effects of seismic shaking include several types of ground failure as well as induced flooding.
Ground failure that could occur as a consequence of severe ground shaking, include landslides, ground lurching,
shallow ground rupture, and liquefaction/lateral spreading. The likelihood of occurrence of each type of ground
failure depends on the severity and distance from the earthquake epicenter, topography, geologic structure,
groundwater conditions, and other factors. All of the secondary effects of seismic activity listed above are
considered to be unlikely, based on our experience, subsurface exploration, and laboratory testing.
Seismically induced flooding is normally associated with a tsunami (seismic sea wave), a seiche (i.e., a wave-
like oscillation of surface water in an enclosed basin that may be initiated by a strong earthquake) or failure of a
major reservoir or retention system up gradient of the site. As a result of the site being at an elevation of more
than 1,000 feet above mean sea level and being more than 25 miles inland from the nearest coastline of the
Pacific Ocean, the potential for seismically induced flooding due to a tsunamis is considered remote. The
likelihood of induced flooding due to a seiche overcoming a dam's freeboard is considered remote. In addition,
it is considered remote that any major reservoir up gradient of the subject property would be compromised to a
point of failure.
Liquefaction and Lateral Spreading
The three requirements for liquefaction to occur include seismic shaking, poorly consolidated cohesionless
sands, and groundwater. Liquefaction results in a substantial loss of shear strength in loose, saturated,.
cohesionless soils subjected to earthquake induced ground shaking. Potential impacts from liquefaction include
loss of bearing capacity, liquefaction related settlement, lateral movements, and surface manifestation in the
form of sand boils. The potential for design level earthquake induced liquefaction and lateral spreading to occur
I beneath the proposed structure is considered very low to remote due to the recommended compacted fill and the
dense nature of the deeper onsite soils.
Ground Subsidence
Groundwater or oil withdrawal from soils can cause a permanent collapse of pore space previously occupied by
the fluid. The consolidation of subsurface sediments resulting from fluid withdrawal may cause the ground
surface to subside, potentially resulting in differential subsidence which can significantly damage engineered
structures. Since excessive withdrawal of fluids is not anticipated in the vicinity of the proposed project, the
potential for subsidence is considered low to remote.
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January 25, 2017 16 CW Soils
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PRELIMINARY FOUNDATION DESIGN RECOMMENDATIONS
General
Shallow foundations are considered feasible for support of the proposed structures, provided grading and
construction are performed in accordance with the recommendations of this report. Foundation
recommendations are provided in the following sections. Graphic presentations of relevant information and
recommendations are also included on Plate 1 —Geotechnical Map.
Allowable Bearing Values
An allowable bearing value of 2,000 pounds per square foot (psf) is recommended for design of 12 inch wide
continuous footings founded at a minimum depth of 12 inches below the lowest adjacent final grade and 24 inch
square pad footings. This value may be increased by 20 percent for each additional I-foot of width and/or depth
to a maximum value of 2,500 psf. Recommended allowable bearing values include both dead and frequently
applied live loads and may be increased by one third when designing for short duration wind or seismic forces.
Settlement
We estimate that the maximum total settlement of the footings will be less than approximately '/, inch, based oil
the anticipated loading and the settlement characteristics of the underling earth materials. Differential
settlement is expected to be about 'h inch over a horizontal distance of approximately 20 feet, for an angular
distortion ratio of 1:480. The majority of the settlement is anticipated to occur during construction or shortly
after the initial application of loading.
The above settlement estimates are based on the assumption that the grading and construction are performed in
accordance with the recommendations presented in this report. Additionally, the project soils consultant or his
representative will be provided the opportunity to observe the foundation excavations.
Lateral Resistance
Passive earth pressure of 250 psf per foot of depth to a maximum value of 2,500 psf may be used to establish
lateral bearing resistance for footings. A coefficient of friction of 0.36 times the dead load forces may be used
between concrete and the supporting soils to determine lateral sliding resistance. When combining passive and
friction for lateral resistance, the passive component should be reduced by one third. In no case shall the lateral
sliding resistance exceed one-half the dead load for clay, sandy clay, sandy silty clay, silty clay, and clayey silt.
The above lateral resistance values are based on footings for an entire structure being placed directly against
compacted fill.
Expansive Soil Considerations
The preliminary laboratory test results indicate that the onsite soils exhibit an expansion potential of LOW as
classified by the 2013 CBC Section 1803.5.1 and ASTM D4829-03.
Additional, testing for expansive soil conditions should be conducted upon completion of rough grading and
prior to construction. The following recommendations should be considered the very minimum requirements,
for the soils tested. It is common practice for the project architect or structural engineer to require additional
slab thickness, footing sizes, and/or reinforcement.
an uary25, 2017 11 CW Soils
Low Expansion Potential (Expansion Index of 21 to 50)
Our laboratory test results indicate that the soils onsite exhibit a LOW expansion potential as classified by the
2013 CBC Section 1803.5.3 and ASTM D4829-03. As such, the CBC specifies that slab on grade foundations
floor slabs) resting on soils with expansion indices greater than 20, require special design considerations per
the 2013 CBC Sections 1808.6.1 and 1808.6.2. The design procedures incorporate the thickness and plasticity
index of the various soils within the upper 15 feet of the proposed structure. We have assumed an effective
plasticity index of 12, for preliminary design purposes.
Conventional Footings
Exterior continuous footings should be founded at the minimum depths below the lowest adjacent
final grade (i.e. minimum 12 inch depth for one-story, minimum 18 inch depth for two-story, and
minimum 24 inch depth for three-story construction). Interior continuous footings for one-, two-,
and three-story construction may be founded at a minimum depth of 12 inches below the lowest
adjacent final grade. In accordance with Table 1809.7 of the 2013 CBC, all continuous footings
should have a minimum width of 12, 15, and 18 inches, for one-, two-, and three-story structures,
respectively, and should be reinforced with a minimum of two (2) No. 4 bars, one (1) top and one (1)
bottom.
Exterior pad footings intended to support roof overhangs, such as second story decks, patio covers
and similar construction should be a minimum of 24 inches square and founded at a minimum depth
of 18 inches below the lowest adjacent final grade. The pad footings should be reinforced with a
minimum of No. 4 bars spaced a maximum of 18 inches on center, each way, and should be placed
near the bottom-third of tile footings.
Building Floor Slabs
Building floor slabs should be a minimum of 4 inches thick. All Floor slabs should be reinforced
with a minimum of No. 3 bars spaced a maximum of 18 inches on center, each way, supported by
concrete chairs or bricks to ensure desired mid-depth placement. Based on an assumed effective
plasticity index of 12, the project architect or structural engineer should evaluate minimum floor slab
thickness and reinforcement in accordance with 2013 CBC Section 1808.6.2.
Building floor slabs with moisture sensitive or occupied areas, should be underlain by a minimum
10-mil thick moisture barrier to help reduce the upward migration of moisture from the underlying
soils. The moisture barrier should be properly installed using the guidelines of ACI publication 318-
05 and meet the performance standards of ASTM E 1745 Class A material. Prior to placing
concrete, it is the responsibility of the contractor to ensure that the moisture barrier is properly
placed and free of openings, rips, or punctures. As an option for additional moisture protection and
foundation strength, higher strength concrete, such as a minimum compressive strength of 5,000
pounds per square inch (psi) in 28-days may be used. In addition, a capillary break/vapor retarder
for concrete slabs should be provided in accordance with CALGreen. Ultimately, the design of the
moisture barrier system along with recommendations for concrete placement and curing are the
purview of the foundation engineer, factoring in the project conditions provided by the architect and
owner.
January25, 2017 12 CW Soils
1
Garage floor slabs should be a minimum of 4 inches thick and should be reinforced in a similar
manner as living area floor slabs. Garage floor slabs should be placed separately from adjacent wall
footings with a positive separation maintained with % inch minimum felt expansion joint materials
and quartered with weakened plane joints. A 12 inch wide turn down founded at the same depth as
adjacent footings should be provided across garage entrances. The turn down should be reinforced
with a minimum of two (2) No. 4 bars, one (1) top and one (1) bottom.
Prior to placing concrete, the subgrade soils below all Floor slabs should be pre-watered to achieve a
moisture content that is at least equal or slightly greater than optimum moisture content. The
moisture content should penetrate a minimum depth of 6 inches into the subgrade soils. The pre-
watering should be verified by CW Soils during construction.
Post Tensioned Slab/Foundation Design Recommendations
In lieu of the proceeding foundation recommendations, post tensioned slabs may be used for the proposed
structures. Post tension foundations are generally considered to be a better foundation system, but may be
slightly higher in overall cost. The foundation engineer may design the post tensioned foundation system using
the following Post Tensioned Foundation Slab Design table. These parameters have been provided in general
accordance with Post Tensioned Design. Alternate designs addressing the effects of expansive soils are allowed
per 2013 CBC Section 1808.6.2. When utilizing these parameters, the foundation engineer should design the
foundation system in accordance with the allowable deflection criteria of applicable codes.
It should be noted that the post tensioned design methodology is partially based on the assumption that soils
moisture changes around and underneath post tensioned slabs, are only influenced by climate conditions. With
regard to expansive soils, moisture variations below slabs are the major factor in foundation damage. However,
the design methodology does not take into account presaturation, owner irrigation, or other non-climate related
influences on the moisture content of the subgrade soils. In recognition of these realities, we modified the soils
parameters obtained from this methodology to help account for reasonable irrigation practices. Additionally,
the slab subgrades should be presoaked to a depth of 12 inches and maintained at above optimum moisture until
placing concrete. Furthermore, prior to placing concrete, the subgrade soils below all floor slabs and perimeter
footings should be presoaked to achieve moisture contents at least 1.0. 1.1, 1.2, and 1.3 times optimum to
depths of 6, 12, 18, and 24 inches for Low, Medium, High, and Very High expansion potential soils.
respectively. The moisture content should penetrate to a minimum depth of 24 inches into the subgrade soils.
The pre-watering should be verified and tested by CW Soils.
Ponding water near the foundation can significantly change the moisture content of the soils below the
foundation, causing excessive foundation movement and detrimental effects. Our recommendations do not
account for excessive irrigation and/or incorrect landscape designs. To prevent moisture infiltration below the
foundation, planters placed adjacent to the foundation should be designed with an effective drainage system or
liners. Some lifting of the perimeter foundation should be expected even with properly constructed planters.
Future owners should be informed and educated of the importance in maintaining a consistent level of moisture
within the soils around structures. Potential negative consequences can result from either excessive watering or
allowing expansive soils to become too dry. Expansive soils will shrink as they dry, followed by swelling
during the rainy winter season or when irrigation is resumed, causing distress to site improvements.
January 25, 2017 13 CW Soils
1
Post Tensioned Foundation Slab Design
PARAMETER VALUE
Expansion Index Low
Percent Finer than 0.002 mm in the 20 percent(assumed)
Fraction Passing the No.200 Sieve
Clay Mineral Type Montmori I[on itc(assumed)
Thornthwaite Moisture Index 20
Depth to Constant Soil Suction 7 feet
Constant Soil Suction P.F. 3.6
Moisture Velocity 0.7 inch/month
Center Lift Edge moisture 5.5 feet
variation distance, e,,2.0 inches
Center lift, ym
Edge Lift Edge moisture 3.0 feet
variation distance, em 0.8 inches
Edge lift,y,n
Soluble Sulfate Content for Design of Negligible
Concrete Mixtures in Contact with Soils
Modulus of Subgrade Reaction, k
assuming presaturation as indicated 200 pci
below
Minimum Perimeter Foundation 12
Embedment
Perimeter Foundation Reinforcement
Under Slab Moisture Barrier and Sand 10-mil thick moisture barrier meeting the requirements of a ASTM E 1745 Class A material
Layer
1. Assumed for design purposes or obtained by laboratory testing.
2. Recommendations for foundation reinforcement are ultimately the purview of the foundation/structural engineer based upon the
soils criteria presented in this report and structural engineering considerations.
Structural Setbacks and Building Clearance
Structural setbacks are required by the 2013 California Building Code (CBC). No additional structural setbacks
are required due to geologic or soils conditions within the site. Improvements constructed near natural or
properly compacted engineered slopes can, over time, be affected by natural processes including gravity forces,
shrink/swell processes, weathering, and long term secondary settlement. As a result, the CBC requires that
structures be setback or footings deepened to resist the influence of these processes.
1
For structures that are planned near ascending and descending slopes, the footings should be embedded to
satisfy the requirements presented in the 2013 CBC, Section 1808.7. Foundations are required to be founded in
accordance with the Foundation Clearances from Slopes Detail (CBC, 2013), which is illustrated in the last
Appendix of this report.
When determining the required clearance from ascending slopes with a retaining wall at the toe, the height of
the slope shall be measured from the top of the wall to the top of the slope.
Foundation Observations
Prior to the placement of forms, concrete, or steel, all foundation excavations should be observed by the
geologist, engineer, or his representative to verify that they have been excavated into competent bearing
January 25, 2017 14 CW Soils
materials, in accordance with the 2013 CBC. The foundations should be excavated per the approved plans,
moistened, cleaned of all loose materials, trimmed neat, level, and square. Moisture softened soils should be
removed prior to steel or concrete placement. Soils from foundation excavations should be removed from slab
on grade areas, unless they have been properly compacted and tested.
Corrosivity
Corrosion is defined by the National Association of Corrosion Engineers (NACE) as "a deterioration of a
substance or its properties because of a reaction with its environment." From a soils engineering point of view,
the "substances" are the reinforced concrete foundations or buried metallic elements (not surrounded by
concrete) and the "environment" is the prevailing soils in contact with thetas. Many factors can contribute to
corrosivity, including the presence of chlorides, sulfates, salts, organic materials, different oxygen levels, poor
drainage, varying soils consistencies, and moisture content. It is not considered practical or realistic to test for
all of the factors which may contribute to corrosivity.
The level of chlorides considered to be significantly detrimental to concrete is based upon the industry
recognized Caltrans standard `Bridge Design Specifications". Under subsection 8.22.1 of that document,
Caltrans established that "Corrosive water or soil contains more than 500 parts per million (ppm) of chlorides".
Based on limited testing, the onsite soils tested have chloride contents less than 500 ppm. Therefore, specific
requirements resulting from elevated chloride contents are not required.
When the soluble sulfate content of soils exceeds 0.1 percent by weight, specific guidelines for concrete mix
design are provided in the 2013 CBC Section 1904 and in ACI 318, Section 4.3 Table 4.3.1. Based on limited
testing, the onsite soils are classified as having a negligible sulfate exposure condition, in accordance with
Table 4.3.1. Therefore, structural concrete in contact with onsite soils should utilize Type i or 11.
The onsite soils in contact with buried steel should be considered mildly corrosive, based on our laboratory
testing of resistivity. Additionally, pH values below 9.7 are recognized as being corrosive to most common
metallic components including, copper, steel, iron, and aluminum. The pH values for the soils tested were
lower than 9.7. Therefore, any steel or metallic materials that are exposed to the soils should be encased in
concrete or other remedies applied to provide corrosion protection.
For structures utilizing post tensioned systems, the post tensioning cables should be encased in concrete and/or
encapsulated in accordance with the Post Tensioning Institute Guide Specifications. If post tensioning cable
end plate anchors and nuts are exposed, they should also be protected. If the anchor plates and nuts are recessed
into the edge of the concrete slab, the recess should be filled in with a non-shrink, non-porous, moisture-
insensitive epoxy grout so that the anchorage assembly and the end of the cable are completely encased and
isolated from the soils. A standard non-shrink, non-metallic cementations grout may be used only when the
t post tension anchoring assembly is polyethylene encapsulated, similar to that offered by Hayes Industries. LTD
or O'Strand. Inc.
It should be noted that CW Soils are not corrosion engineers and the test results for corrosivity are based on
limited samples thought to be representative. The grading operations may blend various soils together and/or
unveil soils with higher corrosive properties. This blending or imported material could alter and increase the
detrimental properties of the onsite soils. Thus, it is important that additional testing near final grades for
chlorides and sulfates along with testing for pH and resistivity be performed upon completion of the grading
operations. Laboratory test results are presented in Appendix C.
1
January 25, 2017 15 CW Soils
RETAINING WALLS
Active and At-Rest Earth Pressures
Retaining wall foundations may be designed in accordance with the recommendations provided in the
Preliminary Foundation Design Recommendation section of this report. For design of retaining walls up to 6
feet high, the table below provides the minimum recommended equivalent fluid pressures.
The active earth pressure should be used for design of unrestrained retaining walls, which are free to tilt
slightly. The at-rest earth pressure should be used for design of retaining walls that are restrained at the top,
such as basement walls, curved walls with no joints, or walls restrained at corners. For curved walls, active
pressure may be used if tilting is acceptable and construction joints are provided at each angle point and at a
minimum of 15 foot intervals along the curved segments.
MINIMUM STATIC EQUIVALENT FLUID PRESSURE c
BACKSLOPE CONDITION
PRESSURE TYPE
LEVEL 2:1 h:v
Active Earth Pressure 40 63
At-Rest Earth Pressure 60 95
Hydrostatic pressure behind the retaining walls has not been taken into account when calculating the parameters
provided. Therefore, the subdrain system is a very important part of the design. If additional loads are being
applied within a 1:1 plane projected up from the heel of the retaining wall footing, due to surcharge loads
imposed by other nearby walls, structures, vehicles, etc., then additional pressure should be added to the above
earth pressures to account for the expected surcharge loads. In order to minimize surcharge loads and the
settlement potential of nearby structures, the footings for the structure can be deepened below the 1:1 plane
projected up from the heel of the retaining wall footing.
1 Upon request and under a separate scope of work, more detailed analyses can be provided to address retaining
wall designs with regard to value engineering, stepped retaining walls, actual retaining wall heights, actual
backfill inclinations, specific backfill materials, higher retaining walls requiring earthquake design motions, etc.
Subdrain System
To prevent the buildup of hydrostatic pressure behind the proposed retaining walls, we recommend a perforated
pipe and gravel subdrain system be provided behind all retaining walls. The subdrain system should consist of
4 inch minimum diameter Schedule 40 PVC or ABS SDR-35 perforated pipe, placed with the perforations
facing down. The pipe should be surrounded by a minimum of 1 cubic foot per foot of or 1%z inch open
graded gravel wrapped in Mirafi 140N or equivalent filter fabric, to prevent infiltration of fines and subsequent
clogging of the subdrain system.
In addition, the retaining walls should be adequately coated on the backfilled side of the walls with a proven
waterproofing compound by an experienced professional to inhibit infiltration of moisture through the walls.
1
Jan uary 25, 2017 16 CWSoils
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Temporary Excavations
All excavations should be made in accordance with Cal-OSHA requirements. CW Soils is not responsible for
job site safety.
Retaining Wall Backfill
Retaining wall backfill materials should be approved by the soils engineer or his representative prior to
placement as compacted fill. Retaining wall backfill should be placed in lifts no greater than 6 to 8 inches,
watered or air dried as necessary to achieve near optimum moisture contents. All retaining wall backfill should
be compacted to a minimum of90 percent of the maximum dry density as determined by ASTM D1557. When
practical, retaining wall backfill should be capped with a paved surface drain.
EXTERIOR CONCRETE
Subgrade Preparation
Subgrade soils underlying concrete fla6vork should be compacted at near optimum moisture to a minimum of
90 percent of the maximum dry density as determined by ASTM test method D1557-12. Prior to placing
concrete, the subgrade soils should be moistened to at least optimum or slightly above optimum moisture
content (see table below). Pre-watering of the soils prior to placing concrete wilt promote uniform curing of the
concrete and minimize the development of shrinkage cracks. The higher the expansion potential of the onsitc
soils the longer it will take to achieve the recommended presaturation. Therefore, the procedure and timing
should be planned in advance.
Flatwork Design
Cracking within concrete flatwork is often a result of factors such as the use of too high of a water to cement
ratio and/or inadequate steps taken to prevent moisture loss during the curing of the concrete. However. minor
cracking within concrete flatwork is normal and should be expected. It should be noted that the reduction of
slab cracking is often a function of proper slab design, concrete mix design, placement, curing, and finishing
practices. We recommend the adherence to the guidelines of the American Concrete Institute(ACI).
When placed over expansive soils, exterior concrete elements are susceptible to lifting and cracking. When this
occurs with highly expansive soils, the detrimental impacts can be significant and may necessitate the removal
and replacement of the affected improvements. In order to reduce the potential for unsightly cracking, we
suggest a combination of presaturation of the subgrade soils, reinforcement, restraint, and a layer of granular
materials. Although these measures may not completely eliminate distress to concrete improvements, the
application of these measures can significantly reduce the distress caused by expansive soils. The degree and
extent the measures recommended in the following table are applied depend on:
The expansion potential of the subgrade soils.
The practicality of implementing the measures (such as presaturation).
The benefits verse the economics of the measures.
The project owner should perform a cost/benefit analysis on the factors to determine the extent the measures
will be applied to each project. The expansive potential of the onsite soils should be considered LOW.
January 25, 2017 17 CW Soils
CONCRETE FLATWORK
CONSTRUCTION EXPANSION INDEX
DESIGN VERY LOW LOW MEDIUM HIGH VERY HIGH
Slab Thickness, Minimum 3.5 inches 3.5 inches 4 inches 4 inches 4.5 inches
Subbase, Gravel Layer NA NA Optional 3 inches 4 inches
Presaturation,Relative to Pre-wet Optimum 1.1 x Optimum 1.2 x Optimum 1.3 x Optimum
Optimum Moisture Content NA 6 inches Deep 12 inches Deep 18 inches Deep 24 inches Dee
Joint, Maximum Spacing, 10 feet or less 10 feet or less 8 feet or less 6 feet or less 6 feet or less
Ooint to extend '/4 slab
Optional No. 3 Rebar No. 3 Rebar
Reinforcement, Mid-Depth NA NA WWF 6 x 6 24" On Center 24" On Center
W I A x W 1.4) Both Was Both Ways
Restraint, Slip Dowels Across Cold Across Cold
Mid-Depth
NA NA Optional
Joints Joints
The use of a granular layer for exterior slabs is primarily intended to facilitate presaturation and subsequent
construction operations by providing a working surface over the saturated soils and to help retain the moisture.
Where these factors are insignificant, the layer may be omitted.
GRADING PLAN REVIEW AND CONSTRUCTION SERVICES
This report has been prepared for the exclusive use of Sultan and Kuldip Singh and their authorized
representative. It is unlikely to contain sufficient information for other parties or other uses. CW Soils should
be provided the opportunity to review the final design plans and specifications prior to construction, in order to
verify that the recommendations have been properly incorporated into the project plans and specifications. If
CW Soils is not accorded the opportunity to review the project plans and specifications, we are not
responsibility for misinterpretation of our recommendations.
We recommend that CW Soils be retained to provide soils engineering and engineering geologic services during
the grading and foundation excavation phases of work, in order to allow for design changes in the event that the
subsurface conditions differ from those anticipated prior to construction.
CW Soils should review any changes in the project and modify the conclusions and recommendations of this
report in writing. This report along with the drawings contained within are intended for design input purposes
only and are not intended to act as construction drawings or specifications. In the event that conditions during
grading or construction operations appear to differ from those indicated in this report, our office should be
notified immediately, as appropriate revisions may be required.
REPORT LIMITATIONS
Our services were performed using the degree of care and skill ordinarily exercised, under similar
circumstances, by reputable soils engineers and geologists, practicing at the time and location this report was
prepared. No other warranty, expressed or implied, is made as to the conclusions and professional advice
included in this report.
Soils vary in type, strength, and other engineering properties between points of observation and exploration.
Groundwater and moisture conditions can also vary due to natural processes or the works of man on this or
January 25, 2017 18 CW Soils
adjacent properties. As a result, we do not and cannot have complete knowledge of the subsurface conditions
beneath the proposed project. No practical study can completely eliminate uncertainty with regard to the
anticipated geologic and soils engineering conditions in connection with a proposed project. The conclusions
and recommendations within this report are based upon the findings at the points of observation and are subject
to confirmation by CW Soils based on the conditions revealed during grading and construction operations,
This report was prepared with the understanding that it is the responsibility of the owner, to ensure that the
conclusions and recommendations contained herein are brought to the attention of the other project consultants
tand
are incorporated into the plans and specifications. The owners' contractor should implement the
recommendations in this report and notify the owner as well as our office if they consider any of the
recommendations presented herein to be unsafe or unsuitable.
1
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January 25, 2017 19 CW Soils
1
APPENDIX A
REFERENCES
APPENDIX A
References
California Building Standards Commission, 2013, 2013 California Building Code, Cal{fornia Code of
Regulations Title 24, Part 2, Volume 2 of 2, Based on 2012 International Building Code.
California Geological Survey, 2008, Guidelines,for Evaluating and Mitigating Seismic Hazards in California,
Special Publication I I7A, September I I, 2008.
Hart, Earl W. and Bryant, William A., 1997, Fault Rupture hazard Zones in California, CDMG Special
Publication 42, revised 2003.
Morton, D.M., Hauser, Rachel M., and Ruppert, Kelly R., 2004, Preliminary Digital Geologic Map of the Santa
Ana 30'x 60' Quadrangle, Southern California, Version 2.0: U.S. Geological Survey Open-File Report
99-0172.
Morton, D.M. (compiler), and Fred K. Miller (compiler), 2006, Geologic Map of the San Bernardino and Santa
Ana 30'x 60'Quadrangle, California: U.S. Geological Survey, Version 1, California.
National Association of Corrosion Engineers, 1984, Corrosion Basics An Introduction, page 191.
Southern California Earthquake Center (SCEC), 1999, Recommended Procedures for Implemenlation of DMG
Special Publication 117, Gtddelines,for Analyzing and Mitigating Giquefaclion Hazards in California,
March.
1
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January 25, 2017 2 CW Soils
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APPENDIX B
FIELD EXPLORATION
Project: Singh Residence Project No.: 16585-10 Equip.: Case 460E Backhoe Logged by: CEW I Date: 1-6-17
sample
Depth(ft) Classification my Density(Pcf) Moisture(^rl Graphic Log: East Wall Scale: 1"=5' Orientation:North Elevation(ft):NA
No.
A -Quaternary Young Alluvium(Qya):
Bag 1 o-a
Silty SAND; medium brown, moist to very moist, loose0-5'
B -Quaternary Pauba Formation(Qps):
a
Silty SANDSTONE;light brown,slightly moist, moderately hard slightly porous
Total Depth(feet): 7 No Groundwater
I I
i
Test Pit 1
Project: Singh Residence Project No.: 16585-10 Equip.: Case 460E Backhoe Logged by: CEW I Date: 1-6-17
Sample GraphicClassificationoryDenaRylaFlmoiataretipGraphic Log:East Wall Scale: I"=5' Orientation:North Elevation(ft):NA
No.
A -Quaternary Young Alluvium (Qya):
3
Silty SAND:medium brown,moist, loose
B -Quaternary Pauba Formation (Qps):
s-6
Silty SANDSTONE; light brown, slightly moist to moist,moderately hard
C -moderately hard to hard
Total Depth(feet): 6 No Groundwater
II
Test Pit 2
1
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APPENDIX C
LABORATORY PROCEDURES AND TEST
RESULTS
1
APPENDIX C
Laboratory Procedures and Test Results
Our laboratory testing has provided quantitative and qualitative data involving the relevant engineering properties of the
representative soils selected for testing. Representative samples were tested using the guidelines of the American Society for
Testing and Materials(ASTM)procedures or California Test Methods(CTM).
Soil Classification: The soils observed during exploration were classified and logged in general accordance
with the Standard Practice for Description and Identification of Soils (Visual-Manual Procedure) of ASTM D
2488. Upon completion of laboratory testing, exploratory logs and sample descriptions may have been
reconciled to reflect laboratory test results with regard to ASTM D 2487.
Moisture and Density Tests: For select samples, moisture content and dry density determinations were obtained
using the guidelines of ASTM D 2216 and ASTM D 2937, respectively. These tests were performed on relatively
undisturbed samples and the test results are presented on the exploratory logs.
Maximum Density Tests: The maximum dry density and optimum moisture content of representative samples
were determined using the guidelines of ASTM D1557. The test results are presented in the table below.
SAMPLE MATERIAL MAXIMUM DRY OPTIMUM MOISTURE
LOCATION DESCRIPTION DENSITY (pcl) CONTENT (%)
TP-I @ 0-5 feet Silty SAND 131.0 10.0
Expansion Index: The expansion potential of representative samples was evaluated using the guidelines of
ASTM D 4829. The test results are presented in the table below.
SAMPLE MATERIAL
EXPANSION INDEX
EXPANSION
LOCATION DESCRIPTION I I POTENTIAL
TP-I (a 0-5 feet Silty SAND 37 1 LOW
Minimum Resistivity and pH Tests: Minimum resistivity and pH tests of select samples were performed using
the guidelines of CTM 643. The test results are presented in the table below.
SAMPLE MATERIAL
MINIMUM
LOCATION DESCRIPTION pH RESISTIVITY
ohm-cm)
TP-1 @ 0-5 feet Silty SAND 8.0 2,550
1
1
1
Soluble Sulfate: The soluble sulfate content of select samples was determined using the guidelines of CTM 417,
The test results are presented in the table below.
SAMPLE MATERIAL SULFATE CONTENT
SULFATE EXPOSURE
LOCATION DESCRIPTION by weight)
TP-1 Oa 0-5feet Silty SAND 0.083 1 Negligible
tChloride Content: Chloride content of select samples was determined using the guidelines of CTM 422. The
test results are presented in the table below.
SAMPLE LOCATION MATERIAL DESCRIPTION CHLORIDE CONTENT (ppm)
0-5 feet Silty SAND 80
1
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t
APPENDIX D
SEISMICITY
1
Zt= Desiqn Maps Detailed Report
ASCE 7-10 Standard (33.54530N, 117.1128°W)
Site Class D - "Stiff Soil", Risk Category 1/II/111
Section 11 .4.1 — Mapped Acceleration Parameters
Note: Ground motion values provided below are for the direction of maximum horizontal
spectral response acceleration. They have been converted from corresponding geometric
mean ground motions computed by the USGS by applying factors of 1.1 (to obtain SS) and
1.3 (to obtain Si). Maps in the 2010 ASCE-7 Standard are provided for Site Class B.
Adjustments for other Site Classes are made, as needed, in Section 11.4.3.
From Figure 22-1" Ss = 1 ,773 g
From Figure 22-2"1 S, = 0.698 g
Section 11 .4.2 — Site Class
The authority having jurisdiction (not the USGS), site-specific geotechnical data, and/or
the default has classified the site as Site Class D, based on the site soil properties in
accordance with Chapter 20.
Table 20.3-1 Site Classification
Site Class vs N or N.„ s
A. Hard Rock 5,000 ft/s N/A N/A
B. Rock 2,500 to 5,000 ft/s N/A N/A
C. Very dense soil and soft rock 1,200 to 2,500 ft/s >50 2,000 psf
D. Stiff Soil 600 to 1,200 ft/s 15 to 50 1,000 to 2,000
psf
E. Soft clay soil 600 ft/s 15 1,000 psf
Any profile with more than 10 ft of soil having the
characteristics:
Plasticity index PI > 20,
Moisture content w >- 40%, and
Undrained shear strength s, < 500 psf
F. Soils requiring site response analysis in See Section 20.3.1
accordance with Section 21.1
For SI: 1ft/s = 0.3048 m/s 1lb/ft2 = 0.0479 kN/m2
1
1
Section 11 .4.3 - Site Coefficients and Risk-Targeted Maximum Considered Earthquake
MCER) Spectral Response Acceleration Parameters
Table 11.4-1 : Site Coefficient F.
t
Site Class Mapped MCE A Spectral Response Acceleration Parameter at Short Period
Ss <- 0.25 Ss = 0.50 Ss = 0.75 SS = 1,00 Ss ? 1.25
A 0.8 0.8 0.8 0.8 0.8
8 1.0 1.0 1.0 1.0 1.0
tC 1.2 1.2 1.1 1.0 1.0
D 1.6 1.4 1.2 1.1 1 .0
E 2.5 1.7 1 .2 0.9 0.9
F See Section 11.4.7 of ASCE 7
Note: Use straight-line interpolation for intermediate values of Ss
For Site Class = D and S. = 1.773 g, F. = 1.000
Table 11.4-2: Site Coefficient F.
Site Class Mapped MCE a Spectral Response Acceleration Parameter at 1-s Period
S, <_ 0.10 S, = 0.20 S, = 0.30 S, = 0.40 S, >_ 0.50
A 0.8 0.8 0.8 0.8 0.8
8 1.0 1.0 1.0 1.0 1.0
C 1.7 1.6 1 .5 1.4 1.3
tD 2.4 2.0 1.8 1.6 1.5
E 3.5 3.2 2.8 2.4 2.4
F See Section 11 .4.7 of ASCE 7
Note: Use straight-line interpolation for intermediate values of S,
For Site Class = D and S, = 0.698 g, F, = 1.500
1
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1
Equation (11.4-1): S,, = F,Ss = 1 .000 x 1 .773 1 .773 g
Equation (11.4-2): SN,, = F,S, = 1 .500 x 0.698 = 1 .047 g
Section 11 .4.4 — Design Spectral Acceleration Parameters
Equation (11.4-3): Sps = % S,ns - % x 1 .773 = 1 ,182 g
Equation (11.4-4): Sp, = % SM, = 'G x 1 .047 = 0.698 g
Section 11 .4.5 — Design Response Spectrum
From Figure 22-12"' T, = 8 seconds
Figure 11_4-1: Design Response spectrum
T<T,:S.=So,(0.4 *0.8TIT,
T,ST5Ts:S.=S,
I
3 Ts<T5T4:S.=So,1T
1 nN
T>TL:S.=S=,TiIP0
II
1 mV
u 5m=0.598 -`--------•=----------
a
v l
M
D
N I
V I
f
1
To=0.118 T,=0.591 1.000
Period T(sed
1
1
Section 11 .4.6 — Risk-Targeted Maximum Considered Earthquake (MCEa) Response
Spectrum
1 The VICE„ Response Spectrum is determined by multiplying the design response spectrum above by
1.5.
Sm= 1.773 --
P i
N
X
0Y
y
0
u
C
tp
s i
wt
Toe0,118 Ts=0.591 1.000
Period T(sec)
1
1
1
1
1
Section 11 .8.3 - Additional Geotechnical Investigation Report Requirements for Seismic
Design Categories D through F
From Figure 22-7"' PGA = 0.677
Equation (31.8-1): PGAM = F,.PGA = 1 .000 x 0.677 = 0.677 g
Table 11.8-1: Site Coefficient F,,.,
Site Mapped MCE Geometric Mean Peak Ground Acceleration, PGA
Class
PGA < PGA = PGA = PGA = PGA >_
0.10 0.20 0.30 0.40 0.50
A 0.8 0.8 0.8 0.8 0.8
B 1.0 1.0 1.0 1.0 1.0
C 1.2 1.2 1.1 1.0 1.0
D 1.6 1.4 1.2 1.1 1.0
E 2.5 1.7 1.2 0.9 0.9
F See Section 11.4.7 of ASCE 7
Note: Use straight-line interpolation for intermediate values of PGA
For Site Class = D and PGA = 0.677 g, Fro. = 1.000
Section 21 .2.1 .1 - Method 1 (from Chapter 21 - Site-Specific Ground Motion Procedures
for Seismic Design)
From Figure 22-171" Cas = 0.972
From Figure 22-18f1 Ca, = 0.962
t
1
Section 11 .6 — Seismic Design Category
Table 11.6-1 Seismic Design Category Based on Short Period Response Acceleration Parameter
t RISK CATEGORY
VALUE OF SDs
I or II III IV
Sos < 0.167g A A A
0.167g 5 Sos < 0.33g B B C
0.33g 5 SDs < 0.50g C C D
0.50g <_ Sos D D D
For Risk Category = I and So, = 1.182 g, Seismic Design Category = D
Table 11.6-2 Seismic Design egory Based on 1-S Period Response Acceleration Parameter
t
RISK CATEGORY
VALUE OF So,
I or II III IV
SDI < 0.067g A A A
0.067g <_ SD, < 0.133g B B C
0.133g <_ SD, < 0.20g C C D
0.209 <_ SDI D D D
For Risk Category = I and SDI = 0.698 g, Seismic Design Category = D
Note: When S, is greater than or equal to 0.75g, the Seismic Design Category is E for
buildings in Risk Categories I, 11, and I11, and F for those in Risk Category IV, irrespective
of the above.
Seismic Design Category = "the more severe design category in accordance with
Table 11 .6-1 or 11 .6-2" = D
Note: See Section 11.6 for alternative approaches to calculating Seismic Design Category.
References
1. Figure 22-1:
http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-1 .pdf
2. Figure 22-2:
http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-2.pdf
3. Figure 22-12: http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-
12.pdf
4. Figure 22-7:
http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-7.pdf
5. Figure 22-17: http://earthquake,usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-
17.pdf
6. Figure 22-18: http://earthquake.usgs.gov/hazards/designmaps/downloads/pdfs/2010_ASCE-7_Figure_22-
18.pdf
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APPENDIX E
GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
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CW SOILS
General Earthwork and Grading Specifications
General
Intent: The following General Earthwork and Grading Specifications are intended
to provide minimum requirements for grading operations and earthwork. These
General Earthwork and Grading Specifications should be considered a part of the
recommendations contained in the geotechnical report(s). If they are in conflict
with the geotechnical report(s), the specific recommendations in the geotechnical
report shall supersede these more general specifications. Observations made during
earthwork operations by the Geotechnical Consultant may result in new or revised
recommendations that may supersede these specifications and/or the
recommendations in the geotechnical report(s).
The Geotechnical Consultant of Record: The Owner shall retain a qualified
Consultant of Record (Geotechnical Consultant), prior to commencement of
grading operations or construction. The Geotechnical Consultant shall be
responsible for reviewing the approved geotechnical report(s) and accepting the
adequacy of the preliminary geotechnical findings, conclusions, and
recommendations prior to the commencement of the grading operations or
construction.
Prior to commencement of grading operations or construction, the Owner shall
coordinate with the Geotechnical Consultant, and Earthwork Contractor
Contractor) to schedule sufficient personnel for the appropriate level of
observation, mapping, and compaction testing.
During earthwork and grading operations, the Geotechnical Consultant shall
observe, map, and document the subsurface conditions to confirm assumptions
made during the geotechnical design phase of the project. Should the actual
conditions differ significantly from the interpretive assumptions made during the
design phase, the Geotechnical Consultant shall recommend appropriate changes to
accommodate the actual conditions, and notify the reviewing agency as needed.
The Geotechnical Consultant shall observe the moisture conditioning and
processing of the excavations and fill operations. The Geotechnical Consultant
should perform periodic compaction testing of engineered fills to verify that the
required level of compaction is being accomplished as specified.
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Room
1 The Earthwork Contractor: The Earthwork Contractor (Contractor) shall be
qualified, experienced, and knowledgeable in earthwork logistics, preparation and
processing of excavations to receive compacted fill, moisture conditioning,
processing of fill, and compacting fill. The Contractor shall be provided with the
approved grading plans and geotechnical report(s) for his review and acceptance of
responsibilities, prior to commencement of grading. The Contractor shall be solely
responsible for performing the grading in accordance with the approved grading
plans and geotechnical report(s). The Contractor shall inform the Owner and the
Geotechnical Consultant of work schedule changes at least 24 hours in advance of
such changes so that appropriate personnel will be available for observation and
testing. Assumptions shall not be made by the Contractor with regard to whether
the Geotechnical Consultant is aware of all grading operations.
It is the sole responsibility of the Contractor to provide adequate equipment and
methods to accomplish the grading operations in accordance with the applicable
grading codes and agency ordinances, these specifications, and the
recommendations in the approved grading plan(s) and geotechnical report(s). Any
unsatisfactory conditions, such as unsuitable soils, poor moisture conditioning,
inadequate compaction, insufficient buttress keyway size, adverse weather
conditions, etc., resulting in a quality of work less than required in the approved
grading plans and geotechnical report(s), the Geotechnical Consultant shall reject
the work and may recommend to the Owner that grading operations be stopped
until operations are corrected, at the sole discretion of the Geotechnical Consultant.
Preparation of Areas for Compacted Fill
Clearing and Grubbing: Vegetation, such as brush, grass, roots, and other
deleterious materials shall be sufficiently removed and properly disposed in a
method acceptable to the Owner, Geotechnical Consultant, and governing agencies.
The Geotechnical Consultant shall evaluate the extent of these removals on a case
by case basis. Soils to be placed as compacted fill shall not contain more than 1
percent organic materials (by volume). No compacted fill lift shall contain more
than 10 percent organic matter.
If potentially hazardous materials are encountered, the Contractor shall stop work
and exit the affected area, and a hazardous materials specialist shall immediately be
consulted to evaluate the potentially hazardous materials, prior to continuing to
work in that area.
t It is our understanding that the State of California defines most refined petroleum
products (gasoline, diesel fuel, motor oil, grease, coolant, etc.) as hazardous waste.
As such, indiscriminate dumping or spillage of these fluids may constitute a
misdemeanor, punishable by fines and/or imprisonment, and shall be prohibited.
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The contractor is responsible for all hazardous waste related to his operations. The
Geotechnical Consultant does not have expertise in this area. If hazardous waste is
a concern, then the Owner should contract the services of a qualified environmental
assessor.
Processing: Exposed soils that have been observed to be satisfactory for support of
compacted fill by the Geotechnical Consultant shall be scarified to a minimum
depth of 6 inches. Exposed soils that are not satisfactory shall be removed or
alternative recommendations may be provided by the Geotechnical Consultant.
Scarification shall continue until the exposed soils are free of oversize material and
the working surface is reasonably uniform, flat, and free of uneven features that
would inhibit uniform compaction. The soils should be moistened or air dried as
necessary to achieve near optimum moisture content, prior to placement as
engineered fill.
Overexcavation: The Typical Cut Lot Detail and Typical Cut/Fill Transition Lot
Detail, included herein provide graphic illustrations that depicts typical
overexcavation recommendations made in the approved grading plan(s) and/or
geotechnical report(s).
Keyways and Benching: Where fills are to be placed on slopes steeper than 5:1
horizontal to vertical), the ground shall be thoroughly benched as compacted fill is
placed. Please see the three Typical Keyway and Benching Details with subtitles
Cut Over Fill Slope, Fill Over Cut Slope, and Fill Slope for graphic illustrations.
The lowest bench or smallest keyway shall be a minimum of 15 feet wide (or '/z the
proposed slope height) and at least 2 feet into competent soils as advised by the
Geotechnical Consultant. Typical benching shall be excavated a minimum height
of 4 feet into competent soils or as recommended by the Geotechnical Consultant.
Fill placed on slopes steeper than 5:1 should be thoroughly benched or otherwise
excavated to provide a flat subgrade for the compacted fill. If unstable earth
materials are encountered or anticipated the need for a buttress/stabilization fill may
be required, see Typical Buttress/Stabilization Detail herein.
Evaluation/Acceptance of Bottom Excavations: All areas to receive compacted
fill (bottom excavations), including removal excavations, processed areas, keyways,
and benching, shall be observed, mapped, general elevations recorded, and/or tested
prior to being accepted by the Geotechnical Consultant as suitable to receive
compacted fill. The Contractor shall obtain a written acceptance from the
Geotechnical Consultant prior to placing compacted fill. A licensed surveyor shall
provide the survey control for determining elevations of bottom excavations,
processed areas, keyways, and benching. The Geotechnical Consultant is not
responsible for erroneously located, fills, subdrain systems, or excavations.
1
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Fill Materials
General: Soils to be used as compacted fill should be relatively free of organic
matter and other deleterious substances as evaluated and accepted by the
Geotechnical Consultant.
Oversize: Oversize material is rock that does not break down into smaller pieces
and has a maximum diameter greater than 12 inches. Oversize rock shall not be
included within compacted fill unless specific methods and guidelines acceptable to
the Geotechnical Consultant are followed. For examples of methods and guidelines
of oversize rock placement see the enclosed Typical Oversize Rock Disposal
Detail. The inclusion of oversize materials in the compacted fill shall only be
acceptable if the oversize material is completely surrounded by compacted fill or
thoroughly jetted granular materials. No oversize material shall be placed within
10 vertical feet of finish grade or within 2 feet of proposed utilities or underground
improvements.
Import: Should imported soils be required, the proposed import materials shall
meet the requirements of the Geotechnical Consultant. Well graded, very low
expansion potential soils free of organic matter and other deleterious substances are
usually the most desirable as import materials. It is generally in the Owners best
interest that potential import soils are provided to the Geotechnical Consultant to
determine their suitability for the intended purpose. Prior to starting import
operations, at least 48 hours should be allotted for the appropriate laboratory testing
to be performed.
Fill Placement and Compaction Procedures
Fill Layers: Fill materials shall be placed in areas prepared to receive engineered
fill in nearly horizontal layers not exceeding 8 inches in loose thickness. Thicker
t layers may be accepted by the Geotechnical Consultant, provided field density
testing indicates that the grading procedures can obtain adequate compaction. Each
layer of fill shall be spread evenly and thoroughly mixed to obtain uniformity
within the soils along with a consistent moisture throughout the fill.
Moisture Conditioning of Fill: Soils to be placed as compacted fill shall be
watered, dried, blended, and/or mixed, as needed to obtain relatively uniform
moisture contents that are at or slightly above optimum. The maximum density and
optimum moisture content tests should be performed using the guidelines of the
American Society of Testing and Materials (ASTM test method D1557-00).
Compaction of Fill: After each layer has been moisture conditioned, mixed, and
evenly spread, it should be uniformly compacted to a minimum of 90 percent of the
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maximum dry density as determined by ASTM test method D1557-00.
Compaction equipment shall be adequately sized and be either specifically designed
for compaction of soils or be proven to consistently achieve the required level of
compaction.
Compaction of Fill Slopes: In addition to normal compaction procedures
specified above, additional effort to obtain compaction on slopes is needed. This
may be accomplished by backrolling of slopes with sheepsfoot rollers as the fill is
being placed, by overbuilding the fill slopes, or by other methods producing results
that are satisfactory to the Geotechnical Consultant. Upon completion of grading,
compaction of the fill and the slope face shall be a minimum of 90 percent of
maximum density per ASTM test method DI 557-00.
Compaction Testing of Fill: Field tests for moisture content and density of the
compacted fill shall be periodically performed by the Geotechnical Consultant. The
location and frequency of tests shall be at the Geotechnical Consultant's discretion.
Compaction test locations will not necessarily be random. The test locations may
or may not be selected to verify minimum compaction requirements in areas that
are typically prone to inadequate compaction, such as close to slope faces and near
benching.
Frequency of Compaction Testing: Compaction tests shall be taken at minimum
intervals of every 2 vertical feet and/or per 1,000 cubic yards of compacted
materials placed. Additionally, as a guideline, at least one (1) test shall be taken on
slope faces for each 5,000 square feet of slope face and/or for each 10 vertical feet
of slope. The Contractor shall assure that fill placement is such that the testing
schedule described herein can be accomplished by the Geotechnical Consultant.
The Contractor shall stop or slow down the earthwork operations to a safe level so
that these minimum standards can be obtained.
Compaction Test Locations: The approximate elevation and horizontal
coordinates of each test location shall be documented by the Geotechnical
Consultant. The Contractor shall coordinate with the Surveyor to assure that
sufficient grade stakes are established. This will provide the Geotechnical
Consultant with the ability to determine the approximate test locations and
elevations. The Geotechnical Consultant can not be responsible for staking
erroneously located by the Surveyor or Contractor. A minimum of two grade
stakes should be provided at a maximum horizontal distance of 100 feet and vertical
difference of less than 5 feet.
Subdrain System Installation
Subdrain systems shall be installed in accordance with the approved geotechnical report(s),
the approved grading plan(s), and the typical details provided herein, such as the Typical
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1 Canyon Subdrain System Detail, etc. The Geotechnical Consultant may recommend
additional subdrain systems and/or changes to the subdrain systems described herein, with
regard to the extent, location, grade, or materials depending on conditions observed during
grading or other factors. All subdrain systems shall be surveyed by a licensed land
surveyor, with the exception of retaining wall subdrain systems, to verify line and grade
after installation and prior to burial. Adequate time should be allowed by the Contractor to
complete these surveys.
Excavation
All excavations and overexcavations shall be evaluated by the Geotechnical Consultant
during grading operations. Any remedial removal depths indicated on the geotechnical
maps are estimates only. The actual removal depths and extent shall be determined by the
Geotechnical Consultant based on the field observations of exposed conditions during
grading operations. Where fill over cut slopes are planned, the cut portion of the slope
shall be excavated, evaluated, and accepted by the Geotechnical Consultant prior to
placement of the fill portion of the proposed slope, unless specifically addressed by the
Geotechnical Consultant. Typical details for cut over fill slopes and fill over cut slopes are
provided herein. Foundation excavations should be made in accordance with the
Foundation Clearances from Slopes Detail unless otherwise specified by the site specific
recommendations by the Geotechnical Consultant.
Trench Backfill
1) The Contractor shall follow all OHSA and Cal/OSHA requirements for trench
excavation safety.
2) Bedding and backfill of utility trenches shall be done in accordance with the
applicable provisions in the Standard Specifications of Public Works Construction.
Bedding materials shall have a Sand Equivalency more than 30 (SE>30). The
bedding shall be placed to 1 foot over the conduit and thoroughly jetting to provide
densification. Backfill should be compacted to a minimum of 90 percent of
maximum dry density, from 1 foot above the top of the conduit to the surface.
3) Jetting of the bedding materials around the conduits shall be observed by the
Geotechnical Consultant.
4) The Geotechnical Consultant shall test trench backfill for the minimum compaction
requirements recommended herein. At least one test should be conducted for every
300 linear feet of trench and for each 2 vertical feet of backfill.
S) For trench backfill the lift thicknesses shall not exceed those allowed in the
Standard Specifications of Public Works Construction, unless the Contractor can
demonstrate to the Geotechnical Consultant that the fill lift can be compacted to the
minimum compaction requirements by the alternative equipment or method.
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TYPICAL CUT LOT DETAIL
i
REMOVE UNSUITABLE MATERIA
ORIGINAL GRADE
PROPOSEDGRADE
1:1 PROJECTION TO COMPETENT
T
RELOMPALT
EARTH MATERIALS
OVEREXCAVATE AND
COMPACTED.FILL I 5 FEET MIN BUT VARIES
i 1
COMPETENT EARTH MATERIA
llllr=-=lllll't- Hill
1:1 PROJECTION TO COMPETENT
EARTH MATERIALS
NOTE;REMOVAL BOTTOMS SHOULD BE GRADED WITH A
MINIMUM 2%FALL TOWARDS STREET OR OTHER SUITABLE AREA
AS DETERMINED BY THE GEOTECHN[CAL CONSULTANT)TO
AVOID PONDING BELOW THE BUILDING
NOTE:WHERE DESIGN CUT LOTS ARE EXCAVATED ENTIRELY INTO
COMPETENT EARTH MATERIALS,OVEREXCAVATION MAY STILL
BY NEEDED FOR HARD-ROCK CONDITIONS OR MATERIALS WITH
VARIABLE EXPANSION POTENTIALS
TYPICAL CUT/ FILL TRANSITION LOT DETAIL
1
r r
PROPOSED GRADE-,.,
11I1
PROJECTION TO
COMPETENT MATERIALS
COMPACTED FILL
5 FEET MIN UT VARIESXCAVATENDRECOMPACT
UHk
1
j
TYPICAL BENCHING
NOTE:WHERE DESIGN CUT LOTS ARE EXCAVATED ENTIRELY INTO
COMPETENT MATERIALS,OVEREXCAVATION MAY STILL BY
NEEDED FOR HARD-ROCK CONDITIONS OR MATERIALS WITH
VARIABLE EXPANSION POTENTIALS
TYPICAL KEYWAY & BENCHING DETAIL
FILL SLOPE
PROPOSED GRADE
F L4
colM
NATURALGRADE
COMPACTED FWL
CONTACT BETWEEN SUITABLE AND
UNSUITABLE MATERIALS TO BE REMOV
SQj VARIES H
4 FEET TYPICAy
AyE•
1:1 PROJECTION TO COMPETENT EARTH
MATERIALS FROM PROPOSED TOE OF SLOPE
1:1 TEMPORARY CUT
vuv
5•• YtV• r
r 0.'
VARIES(B FEET TYPICAL
ifill V9111111w
2.0 FEET M
15.0 FEET
KEYWAY DIMENSIONS PER GEOTECHNICAL CONSULTANT/
GEOLOGIST(TYPICALLY H/2 OR 15 FEET MIN.)
KEYWAY BOTTOM SHOULD DESCEND INTO SLOPE
NOTES:
NATURAL SLOPES STEEPER THAN 5:1(H:V)MUST BE KEYED
AND BENCHED INTO COMPETENT EARTH MATERIALS
TYPICAL BUTTRESS/ STABILIZATION DETAIL
OVERECCAVATION OF PAD,AS RECOMMENDED
BY GEOTECHNICAL CONSULTANT
15.0 FEET MIN
4INCH
PERFORATED PVC
PROPOSED GRADE-"RAD BACKDRAIN
41NCH SOLID PVC lU FE MIN
TYPICAL BENCHING
41NCH
PERFORATED PVC PICAL BENCHING yBACKDRAfNMPACIEDFILL
41NCH SOLID PVC 30 •• MAX
OUTLET
2 FE MIN PROJECTED PLANE NO
STEEPER THAN 1:1
FILTERFF RIIC_(MIRAFI 140NORA PRPOVRDEQUIVALE
ryRFORATED PVC PIPE WITH
15.0 FEET
PER RATIONS FACING DOWN
KEYWAY DIMENSIONS PER GEOTECHMCAL CONSULTANT/
GEOLOGIST(TYPICALLY H/2OR 15 FEET MIN)
121NCH MIN OVERLAP, \
ISECUREDEVERY6FEET
IKEYWAYBOTTOMSCHEDULE40SOLIDPVCOUTLETPIPE\ -__
DESCENDING INTO SLOPE SURROUNDED BY COMPACTED FILL. OUTLETS
100 FEET ON CENTER OR LESS I
5 CUBIC FEET/FOOT OF Y4-1 JSINCH OPEN \\
V
GRADED ROCK
TYPICAL KEYWAY & BENCHING DETAIL
FILL OVER CUT SLOPE
PROPOSED GRADE
o
COMPACTED FILL
NATURALGRADE
VARIES
j p - 4 FEET TYPICAL)
I J1SJ,CONTACT BETWEEN SUITABLE AND UNSUITABLE
J
H EARTH MATERIALS TO BE REMOVE
CUTSLOPE
rirwsese[vm:
VARIES(8 FEET TYPICAL
IF
15.0 FEET
KEYWAY DIMENSIONS PER GEOTECHNICAL CONSULTANT/
GEOLOGIST(TYPICALLY H/20R 15 FEET MIN.)
KEYWAY BOTTOM SHOULD DESCEND INTO SLOPE
NOTES:
NATURAL SLOPES STEEPER THAN 5A(H:V)MUST BE KEYED
AND BENCHED INTO COMPETENT EARTH MATERIALS
THE CUT SLOPE MUST BE CONSTRUCTED FIRST
m m = m
TYPICAL KEYWAY & BENCHING DETAIL
CUT OVER FILL SLOPE
CONTACT'BETWEEN SUITABLE AND
UNSUITABLE MATERIALS TO BE REMOV
PROPOSEDGRADE y/
NATURALGRADE
i
F '
PROPOSED GRADE
OVERBUILTCOMPACTEDFILL
10 BE CUTBACK
OVERBUILD AND CUT BACK TO
THE PROPOSED GRADE-,,,
1:1 PROJECTION TO
COMPETENT MATERIA FT
c
TEMPORARY 1:1 CUT
y
Hill- '111111
5.0
2.0 FEET
15.0 FEET
KEYWAY DIMENSIONS PER GEOTECHMCAL CONSULTANT/
GEOLOGIST(TYPICALLY H/2 OR 15 FEET MIN)
KEYWAY BOTTOM SHOULD DESCEND INTO SLOPE
NOTE:
NATURAL SLOPES STEEPER THAN 5:1(H:V)MUST BE
KEYED AND BENCHED INTO COMPETENT MATERIALS
TYPICAL CANYON SUBDRAIN SYSTEM DETAIL
CONTACT BETWEEN SUITABLE AND
UNSUITABLE MATERIAL TO BE REMOVE
PROPOSED
GRADE
COMPACTED FILL
FILTER FABRIC(MIRAFI HON OR APPROVED EQUIVALE
61NCH COLLECTOR PIPE
SCHEDULE 40 PERFORATED PVC PIPE
WD}I PERFORATIONS FACING
NATURALGRADE
f
12 INCHES MIN.OVERLAP,SECURED E4Y 6 FEET 6 MOH
UNSUITABLE MATERIALS TO BE REMOVED
9 CUBIC FEET/FOOTOF Y-I Ih WCH
OPEN GRADED ROCK
TYPICAL BENCHING
COMPETENT MATERIA INCH Mit
NOTES-
1-CONTINUOUS RUNS IN EXCESS OF 500 FEET
LONG WILL REQUIRE AN B INCH DIAMETER PIPE
TYPICAL CANYON SUBDRAIN OUTLET SOLIDFINAL 20 BACRFILLED WITH CONTACTEDUTLETWILL E
FINE-GRAINED MATERIALS
FILTER FABRIC(MIRAD ION OR APPROVED EQUIVALEN
20.0 FEET MI PROPOSEDGRADE
TYPICALLY 10A FEET
COMPACTED FILL
BUTVARIES,
it
61NCHSOUD PVC PIPE
OPENGRADED
ROCK f
D FEET MIN
INCH SOLID PVL PIP INCH PERFORATED SCHEDULE Q PVC PIPE
TYPICAL OVERSIZE ROCK DETAIL
PROPOSEDGRADE
PROPOSED SLOPE FACE
COMPACTED FILL IO 0 FE T MIN
15.0 FEET MIN 20.0 FE T MIN
COMPACTED FILL
2:1 OR LATTER
4 FEE MIN
q
15.0 FEET M
COMPACTED FILL
COMPACTED FILL
WINDROW PARALLEL
OVERSIZED
TO SLOPE FACE
BOULDER
CROSS SECTION A-A'
COMPACTED FILL
JETTING OF APPROVED
GRANULAR MATERIAL Y - 'Ty-+._
s L
NOTE:
OVERSIZE ROCK IS LARGER THAN
EXCAVATED TRENCH 12 INCHES IN MAX DIAMETER
OR DOZER V-CUT
FOUNDATION CLEARANCES FROM SLOPES DETAIL
FACE OF FOOTIN
TOP OF SLOPE
AT LEAST THE SMALLER OF
H/3 AND 40 FEET
FACE OF
STRUCTURE AT LEAST THF.SMALLER OF H/2 AND
15 FEET
4MT;.411A=
N% Add
TOE OF SLOPE
CBC,2010)
PROPOSED (N)DRIVEWAY
W-SOFT Rl
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BUILDI G PAD
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ROPOSED R
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o SH D TO BE D
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1
EXISTING YARDS,
AND DIRT ROADS TO REMAIN i1N.I .C.
LEGEND
L are A,.i.w
Geoloeic Units
O M '
G$`Qya Quaternary Young Alluvial Deposits
Symbols
3-5 Recommended Removal Depth (feet)
Exploratory Test Pit
TP-2
REFERENCE: Google Earth(Version 7.1.5.1557)ISoftwarc(. Mountain View,CA: Google Inc(2015).
Proposed Singh Residence 16585-10
Not to Scale
GEOTECHNICAL MAP 2017 1PLATE 1