HomeMy WebLinkAboutCT 13-05; State Street Townhomes; Tentative Map (CT) (4)PRELIMINARY GEOTECHNICAL INVESTIGATION,
PROPOSED REDEVELOPMENT OF 2531, 2541 AND 2551 STATE STREET,
CARLSBAD, CALIFORNIA
RECEIVED
FEB 0 7 201*1
CITY OF CARLSBAD
PLANNING DIVISION
Prepared for:
SRM DEVELOPMENT, LLC
104 South Division Street
Spokane, Washington 99202
ProjectNo. 041742-001
December 7, 2005
Leighton and Associates, Inc.
A LEIGHTON GROUP COMPANY
4
Leighton and Associates. Inc.
A LEIGHTON GROUP COMPANY
December 7,2005
ProjectNo. 041742-001
To: SRM Development, LLC
104 South Division Street
Spokane, Washington 99202
Attention: Mr. David L. Guthrie
Subject: Preliminary Geotechnical Investigation, Proposed Redevelopment of 2531, 2541,
and 2551 State Street, Carlsbad, Califomia
In accordance with your request and authorization, we have prepared a preliminary geotechnical
investigation report tor the proposed residential redevelopment located at 2531, 2541, and 2551
State Street, Carlsbad, California. Based on the results of our study, it is our professional opinion
that the development of the site is geotechnically feasible provided the recommendations
provided herein are incorporated into the design and construction of the proposed improvements.
The accompanying report presents a summary of the existing conditions ofthe site, the results of
our field investigation and laboratory testing, and provides geotechnical conclusions and
recommendations relative to the proposed site development.
If you have any questions regarding our report, please do not hesitate to contact this
appreciate this opportunity to be of service.
Respectfully submitted,
LEIGHTON AND ASSOCIATES
William D. Olson, RCE 4528
Senior Project Engineer
Distribution: (6) Addressee
Michael R. Stewart, CEG 1349
Principal Geologist/Vice President
3934 Murphy Canyon Road, Suite B205 • San Diego, CA 92123-4425
858.292.8030 • Fax 858.292.0771 • www.leightongeo.com
041742-001
TABLE OF CONTENTS
Section Page
1,0 INTRODUCTION 1
1.1 PURPOSE AND SCOPE 1
1.2 SITE LOCATION 1
1.3 PROPOSED DEVELOPMENT 3
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 4
3.0 SUMMARY OF GEOTECHNICAL CONDITIONS 5
3.1 REGIONAL GEOLOGY 5
3.2 SITE GEOLOGY 5
3.2.1 Undocumented Artificial Rll 5
3.2.2 Terrace Deposits 5
3.2.3 Santiago Formation 6
3.3 GEOLOGIC STRUCTURE 6
3.4 GROUNDWATER 6
3.5 ENGINEERING CHARACTERISTICS OF ONSITE SOILS 6
3.5.1 Expansion Potential 6
3.5.2 Soil Corrosivity 7
3.5.3 Excavation Characteristics 7
4.0 FAULTING AND SEISMICITY 8
4.1 FAULTING 8
4.2 SEISMICTTY 8
4.2.1 Shallow Ground Rupture 10
4.2.2 Liquefaction and Dynamic Settlement 10
4.2.3 Tsunamis and Seiches 10
5.0 CONCLUSIONS 11
6.0 RECOMMENDATIONS 12
6.1 EARTHWORK 12
6.1.1 Site Preparation 12
6.1.2 Excavations and Oversize Material 12
6.1.3 Removal and Recompaction 12
6.1.4 Fill Placement and Compaction 13
6.1.5 Expansive Soils and Selective Grading 13
6.2 SHORING OF EXCAVATIONS 13
6.3 SURFACE DRAINAGE AND EROSION 15
6.4 FOUNDATION AND SLAB CONSIDERATIONS 15
6.4.1 Foundation Design 15
6.4.2 Floor Slabs 15
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TABLE OF CONTENTS (Continued)
Section Page
6.4.3 Settlement 16
6.4.4 Lateral Resistance and Retaining Wall Design Pressures 16
6.5 FLEXIBLE PAVEMENT DESIGN 17
6.6 CONSTRUCTION OBSERVATION AND PLAH REVIEWS 18
7.0 LIMTTATIONS 20
TABLES
TABLE 1 - SEISMIC PARAMETERS FOR ACTIVE FAULTS - PAGE 9
TABLE 2 - STATIC EQUIVALENT FLUID WEIGHT - PAGE 16
TABLE 3 - PRELIMINARY PAVEMENT SECTIONS - PAGE 18
FIGURES
FIGURE 1 - SITE LOCATION - PAGE 2
FIGURE 2 BORING LOCATION MAP - REAR OF TEXT
APPENDICES
APPENDIX A - REFERENCES
APPENDIX B - BORING LOGS
APPENDIX C - SUMMARY OF LABORATORY TESTING
APPENDIX D - SEISMIC ANALYSIS
APPENDIX E - GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING
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1.0 INTRODUCTION
1.1 Purpose and Scope
This report presents the results of our preliminar>' geotechnical investigation for the
proposed State Street redevelopment (the subject site) located at 2531, 2541, and 2551
State Street in Carlsbad, Califomia (Figure 1). The purpose of our investigation was to
evaluate the geoteclmical conditions at the site and provide conclusions and
recommendations relative lo the proposed development. Our scope of services included the
following:
Review of published and unpublished geotechnical reports, maps and aerial
photographs (Appendix A).
Site reconnaissance.
Coordination with Underground Services Alert (USA) to locate potential underground
utilities on site.
Obtaining a County of San Diego, Department of Health, Boring Pemiit.
Excavation, logging and sampling of two exploratory borings. The boring logs are
presented in Appendix B.
Laboratory testing of representative soil samples obtained from the subsurface
exploration program. Results ofthese tests are presented in Appendix C.
Preparation of this report presenting our findings, conclusions, and geotechnical
recommendations with respect to the proposed design, site grading and general
construction considerations.
1.2 Site Location
The subject site is located on the west side of State Street in downtown Carlsbad,
California. Presently, portions ofthe site are occupied by large two-story office buildings
and paved parking areas. Current topography of the site is relatively flat with an existing
surface elevation of roughly 35 mean sea level (msl).
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BASE MAP: 2003 Digital Edition Thomas Guide. San Diego Couniy
NOT TO SCALE
SRM Development
2531, 2541 and 2551 State Street
Carlsbad, California
SITE
LOCATION
MAP
Project No.
041742-001
Date
December 2005 Figure No. 1
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1-3 Proposed Development
It is our imderstanding that the proposed redevelopment of the site wiil to consist of a
four- to five-story residential building with up to two levels of underground parking.
However, it should be noted that preliminar>' foundation designs or structural loads were
not available for the preparation of this report. For the puiposes of this report, we have
assumed the proposed above ground structures will be constructed of structural steel and
below grade stractures will consist of reinforced concrete. Associated improvements are
anticipated to including shoring, underground utilities, landscaping, hardscaping, and may
include some retaining wall structures. Additional geotechnical analysis may be needed
once preliminary foundation designs or structural loads are known.
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2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING
Our subsurface exploration consisted of the excavation of two (2) exploratory borings. The
approximate locations of the borings are shown on the Boring Location Map, Figure 2, The
purpose of these excavations was to evaluate the physical characteristics of the onsite soils
pertinent to the proposed improvements. The borings allowed evaluation of the soils encountered
within proposed excavation area, beneath the proposed subsurface structures, and provided
representative samples for laboratory testing. Prior to drilling tlie exploratory excavations.
Underground Service Alert was contacted to coordinate location and identification of nearby
underground utilities. It should also be noted that no indications (odors, staining, etc.) of
hydrocarbon impacted soils were observed during drilling.
The exploratory excavations were logged by a representative from our firm. Representative bulk
and undisturbed samples were obtained at frequent intervals for laboratory testing, logs of the
borings are presented in Appendix B. Subsequent to logging and sampling, the current borings
were backfilled with bentonite grout per County of San Diego, Department of Environmental
Health requirements.
Laboratory testing was performed on representative samples to evaluate the moisture, density,
shear strength, and geochemical (corrosion) characteristics of the subsurface soils. A discussion
of the laborator)' tests performed and a summary of the laboratory test results are presented in
Appendix C. In-situ moisture and density test results are provided on the boring logs
(Appendix B).
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3.0 SUMMARY OF GEOTECHNICAL CONDmONS
3.1 Regional Geology
The site is located within the coastal subprovince of the Peninsular Ranges Geomorphic
Province, near the westem edge of the southern Califomia batholith. The topography at the
edge of the batholith changes from the mgged landforms developed on the batholith to the
more subdued landfonns, which typify the softer sedimentary formations ofthe coastal plain.
Specifically, the site is underlain by Quatemary Terrace Deposits and Tertiary Santiago
Formation.
3.2 Site Geology
Based on subsurface exploration, aerial photographic analysis, and review of pertinent
geologic literature and maps, the geologic units underlying the site include undocumented
fill, Terrace Deposits, and the Santiago Formation. The approximate areal distribution of
these units is depicted on the Boring Location Map, Figure 2. A brief description of the
geologic units encountered on the site is presented below.
3.2.1 Undocumented Artificial Fill
Undocumented artificial fill soils were found to be on the order of three to four feet
thick. WTiere encountered, these soils consisted of light brown to brown damp to
moist, soft to medium dense, sandy clay to clayey sand. As encountered in our
borings, the fill soils were found to be generally loose and relatively dry near the
surface. Fills are not considered to be suitable for support of stmctures or additional
fill. Existing fills not removed by planned excavations should be removed to
competent formational material and may be reused as fill provided the soil is free of
deleterious materials.
3.2.2 Terrace Deposits
The Quatemary-aged Teixace Deposits is present at grade, or just below the fill
soils, on the majority of the site. As encountered during our field invesfigation,
this unit consists of light brown to brown, damp to moist, medium dense to very
dense, silty sands and clayey sands. These soils are suitable for reuse as structural
fill provided they are free of rock fragments larger than 8 inches in maximum
dimension.
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3.2.3 Santiago Formation
The lertiary-aged Santiago Formation was identified at depth across the site
underlying Tenace Deposits, Based on the exploratory borings on the site, these
materials generally consist of very dense, poorly indurated, light brown to very light
brown, silty sandstones, and silty claystones.
3.3 Geologic Structure
Based on the results of our current investigation, literature review, and our professional
experience on nearby sites, the Terrace Deposits is generally massive to indistinctly
bedded and is flat-lying to slightly dipping (less than 5 degrees) to the west. The Santiago
Fonnation is thinly bedded to massive and slightly dipping (less than 5 degrees) to the
west.
3.4 Ground Water
Ground water was encountered during the subsurface exploration of the site at depth of 16
feet below the ground surface (bgs) in Boring, B-l located on the north end of the site,
and at a depth of 21 feet bgs in Boring, B-2 located on the south end of the site.
3.5 Engineering Characteristics of Onsite Soils
Based on the results of our current geotechnical investigation, laboratory testing of
representative onsite soils, and our professional experience on adjacent sites with similar
soils, the engineering characteristics of the onsite soils are discussed below.
3.5.1 Expansion Potential
Based on previous laboratory testing at similar sites, the onsite Terrace Deposits is
anticipated to be in the very low to low expansion range. The underlying Santiago
Formation may contain soil with a moderate to very high expansion potential,
Geotechnical observations and/or laboratory testing of the excavation materials
are recommended to determine the actual expansion potential of soils on the site.
3.5.2 Soil Corrosivity
The Nafional Association of Corrosion Engineers (NACE) defines corrosion as "
a deterioration of a substance or its properties because of a reaction with its
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environment". From a geotechnical viewpoint, the "environment" is the prevailing
foundation soils and the "substances" are reinforced concrete foundations or
various types of metallic buried elements .such as piles, pipes, etc. that are in
contact with or within close vicinity of the soil. In general soil environments that
are detrimental lo concrete have high concentrations of soluble sulfates and/or pH
values of less than 5.5. Table 19A-4 ofthe 1997 UBC provides specific guidelines
for the concrete mix-design when the soluble sulfate content of the soil exceeds
0.1 percent by weight or 1000 parts per million (ppm). The minimum amount of
chloride ions in the soil environment that are corrosive to steel, either in the form
of reinforcement protected by concrete cover, or plain steel substructures such as
steel pipes or piles is 500 ppm per California Test 532.
The results of our laboratory tests on representative formafional soils from the site
indicated a soluble sulfate content of less than 0.06 percent and a pH of 8 to 8.22
which suggests that the concrete should be designed minimally in accordance with
the neghgible category of Table 19A-A-4 of the 200ICBC. The test results also
indicate a chloride content of 639 to 1,897 ppm, which is considered a posifive to
severe potential for chloride attack and a minimum resistivity value ranging from
1,021 to 1,821 ohm-cm indicating a corrosive degree of corrosivity. The test
results are provided in Appendix C. A corrosion engineer should be contacted to
provide measures to mitigate corrosion, if needed.
3.5.3 Excavation Characteristics
It is anticipated the onsite soils can be excavated with conventional heavy-duty
construction equipment. Localized cemented zones, if encountered, may require
heavy ripping or breaking. If oversize material (larger than 8 inches in maximum
dimensions) is generated, it should be placed in non-stmctural areas or hauled off
site, Beds of gravels and cobbley sands should be anficipated within the surficial
units and underlying formation.
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4.0 FAULTING AND SEISMICITY
4.1 Faulting
Our discussion of faulfing on the site is prefaced with a discussion of Califomia legislation
and state policies conceming the classification and land-use criteria associated with faults.
By definition of the Califomia Mining and Geology Board, an active fault is a fault which
has had surface displacement within Holocene fime (about the last 11,000 years). The State
Geologist has defined a potenfially acfive fault as any fault considered to have been active
during Quatemary time (last 1,6000,000 years) but that has not been proven to be active or
inactive. This definifion is used in delineating Fault-Rupture Hazard Zones as mandated by
the Alquist-Priolo Earthquake Fault Zoning Act of 1972 and as revised in 1997 (Hart,
1997). The intent of this act is to assure that unwise urban development does not occur
across the traces of acfive faults. Based on our review of the Fault-Rupture Hazard Zones,
the site is not located within a Fault-Rupture Hazard Zone as created by the Alquist-Priolo
Act (Hart, 1997) and recentiy modified. In addifion, the site is not located within the City of
San Diego Special Study Zone, which was inacted as an amendment to the 1991 Uniform
Building Code.
Our review of available geologic literature (Appendix A) indicates that there are no
known major or active faults on or in the immediate vicinity ofthe site. The nearest active
regional fault is the offshore segment of the Newport-Inglewood (offshore) fault located
approximately 3.7 miles west ofthe site.
4.2 Seismicity
The site can be considered to lie within a seismically active region, as can all of Southem
Califomia. Table 1 (below) identifies potential seismic events that could be produced by
the maximum moment magnitude earthquake. A maximum moment magnitude
earthquake is the maximum expectable earthquake given the known tectonic framework.
Site-specific seismic parameters included in Table 1 are the distances to the causative
faults, earthquake magnitudes, and expected ground accelerations, llie ground motion
was calculated using the computer software EQFAULT (Blake, 2000) and the attenuation
relationship by Boore (1997) for a soil site profile.
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Table 1
Seismic Parameters for Active Faults
Potential
Causative
Fault
Distance
from Fault
to Site
(Miles/km)
Maximum
Credible
Earthquake
(Moment
Magnitude)
Peak
Horizontal
Ground
Acceleration
(g)
One Standard
Deviafion of Peak
Horizontal Ground
Acceleration
(g)
Newport-
Inglewood 3.7/5.9 7.1 0.41 0.28
Rose
Canyon 4.7/7.6 7.2 0.38 0.26
Coronado
Bank 20.6/33.1 7.6 0.18 0.12
Elsinore -
Julian 24.9/40.1 7.1 0.12 0.08
As indicated in Table 1, the Newport-Inglewood (offshore) Fault is the 'active' fault
considered having the most significant effect at the site from a design standpoint. A
maximum credible earthquake of moment magnitude M7.2 on the fault could produce an
estimated peak horizontal ground acceleration of 0.4lg at the site (0.28g at one standard
deviation confidence interval). The Rose Canyon Fault Zone is considered to be a Type B
seismic source according lo the California Building Code (CBSC, 2001) and the
Califomia Division of Mines and Geology (CDMG, 2002).
From a probabilistic standpoint, the design ground motion is defined as the ground
motion having a 10 percent probability of exceedance in 50 years. This ground motion is
referred to as the maximuni probable ground motion (CBSC, 2001). Based on review of
statewide mapping at the California Geological Survey website
(uavw.consrv.ca.gov/cgs/rghm/pshamap/pshamain.html), the maximum probable ground
motion al the site is postulated to be 0.3lg. Site-specific analysis should be performed if
this value is utilized in structural design.
The effect of seismic shaking may be mitigated by adhering to the Califomia Building
Code or state-of-the-art seismic design parameters of the Structural Engineers
Associafion of Califomia. The site is located within Seismic Zone 4. The soil profile type
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for the site is considered Type Sc (CBSC, 2001). Site coefficients Na of 1.0 and Nv of 1.1
are considered appropriate based on proximity to seismic sources.
Secondary effects that can be associated with severe ground shaking following a
relatively large earthquake include shallow ground mpture, soil liquefaction and dynamic
settlement, seiches and tsunamis. These secondary effects of seismic shaking are
discussed in the follov^'ing sections.
4.2.1 Shallow Ground Rupture
Ground rupture because of active faulting is not likely to occur on site due to the
absence of known active faults. Cracking due to shaking from distant seismic
events is not considered a significant hazard, although it is a possibility at any site
in Southern California.
4.2,2 Liquefaction and Dynamic Settlement
Liquefaction and dynamic settlement of soils can be caused by strong vibratory
motion due to earthquakes. Both research and historical data indicate that loose,
saturated, granular soils are susceptible to liquefaction and dynamic settlement.
Liquefaction is typified by a loss of shear strength in the affected soil layer,
thereby causing the soil to behave as a viscous liquid. This effect may be
manifested by excessive settlements and sand boils at the ground surface.
Based on our exploration and evaluation, the on-site soils are not considered
liquefiable due to their relatively dense condition and absence of a shallow groimd
water condition. Considering planned grading and foundation design measures,
dynamic settlement potential is also considered negligible.
4.2.3 Tsunamis and Seiches
Based on the distance between the site and large, open bodies of water, and the
elevation ofthe site (i.e., estimated at 35 feet msl) with respect to sea level, the
possibility of seiches and/or tsunamis is considered to be negligible.
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5.0 CONCLUSIONS
Based on the results of our geotechnical investigation of the site, it is our professional opinion
that the proposed redevelopment is feasible from a geotechnical standpoint, provided the
following conclusions and recommendations are implemented during the design and constmction
of the project. The following is a summary oflhe significant geotechnical faclors that may affect
redevelopment of the site.
Based on laboratory testing and visual classification, the onsite fill and upper formational
soils generally possess a very low to low expansion potential. However, soils generated from
claystone, if encountered on the sile, will have higher expansion potential and should not be
reused as fill, if encountered.
The existing onsite soils, excluding soil generated from the claystone, appear to be suitable
material for reuse as compacted fill provided they are relatively free of organic material,
debris, and rock fragments larger than 8 inches in maximum dimension.
Based on our experience with similar soils, soils present on the site are expecied to have a
negligible potential for sulfate attack on concrete. The onsite soils are also considered to
have a moderate to severe potential for cortosion to buried uncoated metal conduits.
Laboratory testing should be performed on the onsite soils to verify the corrosivity
characteristics.
Based on the results of our exploration, we anticipate that the onsite materials should be
generally rippable wilh conventional heavy-duty earthwork equipment. However, localized
dense well indurated sandstone and conglomerate lenses should be expected wilhin the
underlying Terrace Deposits and Santiago Fomiation,
Active or potentially active faults are not known to exist on or in the immediate vicinity of
the site.
The peak horizontal ground acceleration on the site due to the maximum moment magnitude
event is postulated to be 0.4lg.
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6.0 RECOMMENDATIONS
6.1 Eartihwork
We anticipate that earthwork at the site will consist of sile preparation, excavation, and
backfill. We recommend lhat earthwork on the site be performed in accordance with the
following recommendations and the General Earthwork and Grading Specifications for
Rough Grading included in Appendix E. In case of conflict, the following
recommendations shall supersede those in Appendix E.
6.1.1 Site Preparation
Prior lo grading, all areas to receive structural fill or engineered structures should
be cleared of surface and subsurface obstmctions, including any existing debris
and undocumented or loose fill soils, and stripped of vegetation. Removed
vegetation and debris should be properly disposed off site. All areas to receive fill
and/or other surface improvements should be scarified to a minimum depth of 6
inches, brought to near-optimum moisture conditions, and recompacted to at least
90 percent relafive compacfion (based on American Standard of Testing and
Materials [ASTM] Test Method D1557).
6.1.2 Excavations and Oversize Material
Excavations of the onsite materials may generally be accomplished v^ith
conventional heavy-duty earthwork equipment. However, local heavy ripping or
breaking may be required if cemented formational material is encountered.
Excavation for utilities may also be difficult in some areas.
Artificial fill soils present on sile may cave during trenching operations. In
accordance with OSHA requirements, excavations deeper than 5 feet should be
sloped or shored in accordance wilh Section 6.2.
6.1.3 Removal and Recompaction
Undocumented fill soils, if encountered beneath any proposed improvements and
not removed by the planned grading, should be excavated down to competent
formational material and replaced with compacted fill. The thickness of these
unsuitable soils may vary across the site and may be locally deeper in certain
areas.
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Where shoring is planned, the design height should consider the planned removal
depths, if encountered.
6-1-4 Fill Placement and Compaction
The onsite soils are generally suitable for reuse as compacted fill provided they
are free of organic material, debris, and rock fragments larger than 6 inches in
maximum dimension. The onsite soils typically possesses a moisture content
below optimum and may require moisture conditioning prior to use as compacted
fill. All fill soils should be brought lo above-optimum moisture conditions and
compacled in unifonn lifts to at least 90 percent relative compaction based on
laborator)' siandard ASTM Te.st Method D1557-91, 95 percent for wall backfill
soils or if used for structural purposes (such as lo support a foofing, wall, etc.).
The optimum Uft thickness required to produce a unifonnly compacted fill will
depend on the lype and size of compaction equipment used. In general, fill should
be placed in lifts not exceeding 8 inches in thickness.
Placement and compaction of fill should be performed in general accordance with
the current Cily of Carlsbad grading ordinances, sound construction practice, and
the General Earthwork and Grading Specifications for Rough Grading presented
in Appendix E.
6.1.5 Expansive Soils and Selective Grading
We anticipate that excavations at the sile will encounter material having a low lo
medium potential for expansion. Expansion testing should be performed on the
finish grade soils lo verify their expansion potential. If highly expansive soils are
preseni wilhin 5 feet of fmish grade, selective grading or special foundaiion and
slab considerations will be required.
6.2 Shoring of Excavations
Based on our present understanding of the project, excavations on the order of 10 to 20
feel deep may be perfonned. Accordingly, and because of the limited space, lemporary
.shoring of vertical excavations will be required. We recommend that excavations be
retained either by a cantilever shoring system deriving passive support from cast-in-place
soldier piles (i.e. lagging-shoring system) or a restrained tie-back and pile sysiem. Based
on our experience with similar projects, if lateral movement of the shoring system on the
order of I to 2 inches cannot be tolerated, we recommend the utilization of a restrained
tie-back and pile system. Shoring of excavations of this size is typically performed by
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specialty contractors wilh knowledge of the San Diego County area soil condhions.
Lateral earth pressures for design of shoring are presented below:
Cantilever Shoring Svstem
Active pressure = 35H (psf), triangular distribulion
Passive Pressure = 350h (psf)
H = wall heighl (active case) or h = embedment (passive case)
Multi-Braced Shoring System
Active Pressure = 25H (psf), rectangular distribulion
Passive Pressure = 350h (psf)
H = wall height (active case) or h = embedment (passive case)
General
All shoring systems should consider adjacent surcharging loads. The design
wall heighl should consider loss of passive support associaied with fooling
excavation.
For design of lie-backs, we recommend a concrete-soil bond stress of 600 psf
of the concrete-soil interface area for straight shaft anchors. This value should
be considered only behind the 40 degree line (measured from the vertical) up
from the base of the excavation. This portion should also be used for
calculating resisting forces. Tie-back anchors should be individually proof-
tested to 150 percent of design capacity. Further details and design crileria for
tie-backs can be provided as appropriate. Since design of retaining systems is
sensitive to surcharge pressures behind the excavation, we recommend that this
office be consulted if unusual load conditions are anticipated. Care should be
exercised when excavating into the on-site soils since caving or sloughing of
these materials is possible. Field testing of tie-backs and observation of soldier
pile excavations should be performed during consiruction.
Settlement monitoring of adjacent sidewalks and adjacent stmctures should be
considered to evaluate the performance of the shoring. Shoring of the
excavation is the responsibility of the contractor. Extreme caution should be
used to minimize damage to existing pavement, utilities, and/or structures
caused by settiement or reduction of lateral support.
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6.3 Surface Drainaqe and Erosion
Surface drainage should be controlled al all times. The proposed structure should have an
appropriale drainage system lo collect roof runoff Positive surface drainage should be
provided to direct surface water away from the siruclure toward the streel or suitable
drainage facilities. Planters should be designed with provisions for drainage to the storm
drain system. Ponding of vvater should be avoided adjacent lo the siruclure.
6.4 Foundation and Slab Considerations
Foundaiions and slabs should be designed in accordance wilh structural considerations
and the following recommendaiions. These recommendations assume that the soils
encountered within 5 feel of pad grade have a very low to low potential for expansion. If
medium to highly expansive soils are encountered and selective grading cannoi be
accomplished, additional foundation design may be necessary.
6.4.1 Foundation Design
The proposed stmctures may be supported by conventional continuous or
isolated spread footings. Footings should extend a minimum of 24 inches
beneath the lowest adjacent soil grade. Al these depths, footings may be
designed for a maximum allowable bearing pressure of 3,000 pounds per
square foot (psl) if founded on undisturbed native soil. The allowable pressure
may be increased by one-third when considering loads of short duration such as
wind or seismic forces. The minimuni recommended widlh of footings is 18
inches for continuous footings and 24 inches for square or round footings.
Continuous footings should be designed in accordance wilh the stmctural
engineer requiremenis and have a niinimum reinforcement of four No. 5
reinforcing bars (two top and two bottom). Reinforcement of isolated footings
should be per the stmctural engineer's design.
6.4.2 Floor Slabs
The slab-on-grade garage floor slab should be al least 6 inches thick and be
reinforced with No, 3 rebars 18 inches on center, each way (minimum), placed
at mid-height in the slab. We emphasize that this is the responsibility of the
conlraclor to ensure that the slab reinforcement is placed at slab midheight.
Slabs should also have crack joints at spacings designed by the stmctural
engineer. Columns should be structurally isolated from slabs. To reduce
moisture migration up through all floor slabs, we recommend installing a 10-
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mil plastic sheeting moLsture banier on 2-inches of clean sand, which is in turn
overlain by an additional 2 inches of clean sand.
6.4.3 Settlement
The recommended allowable-bearing capaciiy is based on a maximum total and
differential settlement of 1 inch and VA of an inch, respectively. Since
settlements are a function of footing size and contacl bearing pressures, some
differential settlement can be expecied between adjacent columns or walls
where a large differential loading condition exists. However for most cases,
differential settlements are considered unlikely lo exceed of an inch. With
increased fooling depth/width ratios, differential settlement should be less.
6.4.4 Lateral Resistance and Retaininq Wall Desiqn Pressures
The proposed retaining walls should be designed for the lateral soil pressures
exerted on them, the magnitude of which depends primarily on the type of soil
used as backfill and the amount of deformation the wall can yield under the
lateral load. If a reiaining wall can yield enough to mobilize the full shear
strength of the soil, it can be designed for the 'active' pressure condition.
Walls that are under restrained conditions and cannot yield under the applied
load (e.g., basement walls) should be designed for the 'at-rest' pressure
condition. If a wall tends to move towards the soils, the resulting resistance
developed by the soil is the 'passive' resistance.
For design purposes, the following lateral earth pressure values for level or
sloping backfill are recommended for walls backfilled wilh onsite soils of very
low to mediuni (EI < 50) expansion potential or imdisturbed in-place materials.
Table 2
Static Equivalent Fluid Weight ( pcf)
Conditions Level 2:1 Slope
Active 35 55
At-Rest 55 75
Passive 350 (Maximum of 3 ksf) 150 (sloping down)
If conditions other than those covered herein are anticipated, the equivalent
fluid pressure values should be provided on an individual case basis by the
geotechnical engineer. A surcharge load for a resfrained or unrestrained wall
resulting from automobile traffic may be assumed to be equivalent to a uniform
-15-Leighton
041742-001
lateral pressure of 75 psf which is in addition to the equivalent fluid pressure
given above. For olher uniform surcharge loads, a uniform pressure equal to
0.35q should be applied to the wall (where q is the surcharge pressure in psf).
The wall pressures assume walls are backfllled with free draining materials and
water is not allowed to accumulate behind walls. A typical drainage design is
attached. Wall backfill should be compacled by mechanical methods to al least
90 percent relative compaction (based on ASTM D1557), We recommend
compaction effort be increased to 95 percent where backfill will support
building foundations of distress sensitive appurtenant improvements. Wall
footings should be designed in accordance wilh the foundation design
recommendations and reinforced in accordance with stmctural considerations.
Lateral soil resistance developed against lateral struclural movement can be
obtained from the passive pressure value provided above. Further, for sliding
resistance, the friction coefficient of 0.35 may be used at the concrete and soil
interface. These values may be increased by one-third when considering loads
of short duraiion including wind or seismic loads. The total resistance may be
taken as the sum of the frictional and passive resistance provided the passive
portion does not exceed two-thirds of the total resistance.
The account for potential redistribution of fbrces during a seismic event,
basement walls should also be checked considering an additional seismic
pressure distribution equal to 20H psf applied as an inverted triangle, where H
equals the overall retained height in feet. If conditions other than those covered
herein are anticipated, the equivalent fluid pressure values should be provided
on an individual case basis by the geotechnical engineer.
We recommend drainage for retaining walls be provided in accordance wilh
Appendix E of this report. Surcharge loading from adjacent structures should
also be taken into account during wall design.
6.5 Flexible Pavement Desiqn
The preliminary pavement design sections (i.e., on-site pavements, if any) have been
provided on Table 3 based on an assumed R-value of at least 15. Final pavement design
should be evaluated based on R-value tests perfomied on represenlative subgrade soils
upon completion of grading. Alternative pavement design sections may be provided once
the appropriate traffic index is selected by the project architect or civil engineer. It should
be noted that the City of Carlsbad pavement requirement presented on the Stmctural
Section of Streets and Alleys, GS-17, will govem for all off-site street pavement
(Carisbad, 1996),
Leighton
041742-001
Table 3
Preliminary Pavement Sections
Pavement
Loading
Condition
Traffic Index
(20-Year
Life)
R-Value of 15
Pavement Sections
Auto Parking
Areas 4,0 3 inches AC over
6 inches Class 2 ba.se
Aulo Driveways 5,0 3 inches AC over
8 inches Class 2 base
For areas subject to unusually heavy truck loading (i.e., trash trucks, delivery tmcks, etc.),
we recommend a full depth seclion of Portland Cement Concrete (PCC) 8 inches thick
with appropriate steel reinforcement and crack-control joints as designed by the project
structural engineer.
All pavement section materials should conform lo and be placed in accordance wilh the
latest revision of the Greenbook and Caltrans guidelines and standard specifications. Prior
to placing the AC pavement seclion, the upper 12 inches of subgrade soils and all
aggregate base should have relative compaction of at least 95 percent (based on ASTM
Test Method D1557).
If pavement areas are adjacent lo heavily watered landscape areas, we recommend some
measure of moisture control be taken to prevent the subgrade soils from becoming
saturated. It is recommended that the concrete curb separating the landscaping area from
the pavement extend below the aggregate base to help seal the ends of the sections where
heavy landscape watering may have access lo the aggregate base. Concrele swales should
be designed in roadway or parking areas subject lo concentrated surface runoff
6.6 Construction Observation and Plan Reviews
The recommendations provided in this report are based on preliminary design information
and subsurface conditions disclosed by widely spaced borings. The interpolated
subsurface conditions should be checked in the field during construction. Consiruction
observation of all onsite excavations and field density testing of all compacled fill should
be performed by a representative of this office so that construction is in accordance with
the recommendations of this report. We recommend lhat where possible excavation
exposures be geologically mapped by the geotechnical consullant during grading for the
presence of potentiaUy adverse geologic conditions.
-18-Leighton
041742-001
Final project drawings should be reviewed by Leighton prior to mobilization for
construction to see thai the recommendaiions provided in this report are incorporaied in
the project plans.
Leighton
041742-001
7.0 LIMITATIONS
The conclusions and recommendations in this report are based in part upon data that were
obtained from a limited nuniber of observations, sile visits, excavations, samples, and tests. Such
information is by necessity incomplete. The nature of many sites is such that differing
geotechnical or geological condilions can occur within small distances and under varying
climatic conditions. Changes in subsurface conditions can and do occur over time. Therefore,
the findings, conclusions, and recommendations presented in this report can be relied upon only
if Leighton has the opportunity to observe the subsurface condilions during grading and
constmction of the project, in order lo confirm that our preliminary findings are represenlative
for tiie site.
Leighton
LEGEND
Parking B-
TD=61.5'
GW=16'
Parking
Parking
-^TD=48'
^_GW=2r
B-2
TD=48'
Approximate location of exploratory boring
^ with total depth indicated
GW=21' Depth to groundwater at the time of drilling
Executive
Suites
2531
Executive
Suites
2541
Executive
Suites
2551
BORING
LOCATION MAP
SRM Development
2531, 2541 and 2551 State Street
Carlsbad, California
Project No.
Scale
Engr/Geol.
Drafted By
Date
041742-001
Not to scale
WDO/MRS
KAM
December 2005
Leighton and Associates, Inc.
M ('1 N (.^ U O IJ C i • M PAN 1 Figure No. 2
041321-001
APPENDIX A
References
Blake, 2000, EQFAULT, Version 3.0.
California Building and Safety Commission (CBSC), 2001, Califomia Building Code.
California Department of Conservation, Division of Mines and Geology (CDMG), 2002, Alquist-
Priolo Special Studies Zone, Preliminary Review Map, Point Loma 7.5-minute
Quadrangle, San Diego County, Califomia: Scale 1:24,000, Released for preliminary
review on November I, 2002, To be superceded on May 1, 2003.
California Geological Survey (CGS), 2004, California ProbabiUstic Seismic Hazard Maps,
November 2004.
Carlsbad, City of, 1996, Standards for Design and Constmction of Public Works Improvements in
the Cily of Carlsbad, Califomia, Project No. 05332-12-01, dated April 20, 1993,
revised December 10, 1996.
CDMG, 1998, Maps of Known Active Fault Near-Source Zones in Califomia and Adjacent
Portions of Nevada, February 1998.
, 1996, Probabilistic Seismic Hazard Assessmenl for the State of Califomia, Open-
File Report, 96-08.
Hart, E.W., 1997, Fault-Rupture Hazard Zones in California, Alquist-Priolo Earthquake Fault
Zoning with Index lo Special Study Zones Maps: Department of Conservation, Division of
Mines and Geology, Special Publication 42,
Jennings, C.W., 1994, Fault Activity Map of Califomia and Adjacent Areas, with Locations and
Ages of Recent Volcanic Eruptions: Califomia Division of Mines and Geology, CaUfomia
Geologic Data Map Series, Map No. 6, Scale 1:750,000.
Kennedy, M.P., 1975, Geology of the San Diego Metropolitan Area, California: Califomia
Division of Mines and Geology Bulletin 200, 38p.
A-l
GEOTECHNICAL BORING LOG KEY
Date
Project ________
Drilling Co.
Hole Diameter
Elevation Top of Elevation
KEY TO BORING LOG GRAPHICS
Sheet 1 of 1
Project No.
Type of Rig
Drive Weight
Location
Drop
Ju.
UJ (3
M
•a
3 S <
o z
V
a. E n (0
wo $o ou-
a.
in
» u
DO. (00)
Oc so O
WOT
OIJ
DESCRIPTION
Logged By
Sampled By
(A V
I-
o
0)
10-
15-
5^ -
20—
25-
30-
B-l
C-1
G-1
R-l
SH-1
S-1
Asphaltic concrete
Portland cement concrete
"a: Inorganic clay of low to medium plasticity; gravelly clay; sandy clay;
_silt>' clay: lean clay TfT
75r
ML Inorganic silt; clayey silt with low plasticity
"MT Inorganic silt; diatomaceous fine sandy or silty soils; elastic silt
Clayey silt to silty clay
Well-graded gravel; gravel-sand mixture, little or no fines
GP Poorly graded gravel; gravel-sand mixture, little or no fines
OM
Clayey gravel; gravel-sand-clay mixture
"W Well-graded sand; gravelly sand, little or no fines
"ST
SNT
Poorly graded sand; gravelly sand, little or no fines
Silty sand; poorly graded sand-silt mixture
"SC
Bedrock
Ground water encountered at time of drilling
Bulk Sample
Core Sample
Grab Sample
Modified Califomia Sampler (3" O.D., 2.5 i.D.)
Shelby Tube Sampler (3" O.D.)
Standard Penetration Test SPT (Sampler (2" O.D., 1.4" l.D.)
SAMPLE TYPES:
S SPLIT SPOON
R RING SAMPLE
B BULK SAMPLE
T TUBE SAMPLE
G GRAB SAMPLE
SH SHELBY TUBE
TYPE OF TESTS:
DS DIRECTSHEAR
MD MAXIMUM DENSITY
CN CONSOLIDATION
CR CORROSION
SA SIEVE ANALYSIS
AT ATTERBURG LIMITS
El EXPANSION INDEX
RV R VALUE
LEIGHTON AND ASSOCIATES, INC.
GEOTECHNICAL BORING LOG B-1
Date 8-25-05
Project
Drilling Co.
SRM/State Street
Sheet 1 of
Project No. 041742-001
West Hazmat Drilling Type of Rig Hollow-Stem Auger
Hole Diameter 8 in. Drive Weight 140 pound tiammer Drop 30"
Elevation Top of Elevation 35' Location 2531 State Street
h •£o> S-O
in « •o
S
<
Q.
E
ns OT
a.
in
Oc SO o
(0^
_OT
CO-' Logged By
Sampled By
DESCRIPTION
DLN
DLN
to
0) H »*—
o
a.
35 XT
30 5—
25 10-
20 IS-
IS 20-
10
5^ 30-
AR-nnClAL nLL (Afu))
@0': Silty CLAY: Brown, moist, soft
SM
I
QUATERNARY TERRACE DEPOSITS (Qt) @ 4': Silty SAND: Brown, moist, very dense
50/6" 111.3 12.2
HC
j
I
41 14.8
3 I 58 101.2 13.4
@ 10': Silty coarse SAND with clay: Brown, damp, medium dense
@ 12': Silly SAND: Light brown, damp
@ 15': Silty SAND: Dark brovm, moist, dense
@ 16': Ground water encountered
26
@ 20": Silty coarse SAND: Light brown, wet, medium dense
@ 21': Silty SAND: Light brown, wet, medium der>se
I 50/6" 12.9 CL
SM
SANTLAGO FORMATION (Tsa)
@ 25': Sandy CLAYSTONE: Light brown, wet, dense
@ 28': Silty fine SANDSTONE; Light brown, very wet
SAMPLE TYPES:
S SPLIT SPOON
R RING SAMPLE
B BULK SAMPLE
T TUBE SAMPLE
G GRAB SAMPLE
SH SHELBY TUBE
TYPE OF TESTS:
DS DIRECTSHEAR
MD MAXIMUM DENSITY
CN CONSOUDATION
CR CORROSION
SA SIEVE ANALYSIS
AT ATTERBURG LIMITS
El EXPANSION INDEX
RV R-VALUE 4 LEIGHTON AND ASSOCIATES, INC.
GEOTECHNICAL BORING LOG B-1
Date
Project
Drilling Co.
8-25-05
SRM/State Street
Sheet 2 of
Project No. 041742-001
West Hazmat Drilling Type of Rig Hollow-Stem Auger
Hole Diameter 8 in. Drive Weight 140 pound hammer Drop 30"
Elevation Top of Elevation 35' Location 2531 State Street
Su.
UJ
|2
•£o> S-O
m
X3
2 e
<
o z »
Q.
E ra
OT
CDo) CL
in
Cit.
QQ-
•»?
OTO
Oc SO o
(OOT
OT~-LoggedBy
Sampled By
DESCRIPTION
DLN
DLN
OT 0) I-
o
0) Q. >.
30-
35-
40—
-10 45—:
-15 50-
-20-55-
-25-> 60-
SAMPLE TYPES:
S SPLIT SPOON
R RING SAMPLE
B BULK SAMPLE
T TUBE SAMPLE
t 90 SM
SANHAGO FORMATION (Continued) (Tsa)
@ 30': Silty SANDSTONE: Light brown, moist, very dense
I 50/6" 119.7 10.4 @ 35': Silty SANDSTONE: Light brown, moist, very dense
80
@ 40': Silty SANDSTONE: Light brown, moist, very dense
I 9 I 68 122.3 9.2
@ 45': Silty SANDSTONE: Light brown, moist, very dense
10 i
I
@ 50': Silly SANDSTONE: Light brown, moist, dense
53
11 I 68 120.2 12.9
@ 55': Silly SANDSTONE: Trace of clay, light brown, moist, dense
G GRAB SAMPLE
SH SHELBY TUBE
TYPE OF TESTS:
DS DIRECT SHEAR
MD MAXIMUM DENSITY
CN CONSOLIDATION
CR CORROSION
SA SIEVE ANALYSIS
AT ATTERBURG LIMITS
El EXPANSION INDEX
RV R-VALUE
LEIGHTON AND ASSOCIATES, INC.
GEOTECHNICAL BORING LOG B-1
8-25-05 Date
Project
Drilling Co. _
Hole Diameter
Elevation Top of Elevation 35'
SRIVI/State Street
West Hazmat Drilling
Sheet 3 of
Project No.
Type of Rig
041742-001
8 in. Drive Weight
Location
140 pound hammer
Hollow-Stem Auger
Drop 301
2531 State Street
tli
Is •So> S-O
in
•o
<
a E ra m
OTO
*.o
DQO)
CL
in
CH-« U
>«
OT^)
Oc
SO o
in'T mm
OT—
DESCRIPTION
Logged By
Sampled By
DLN
DLN
OT
O a> p.
-25 60-"158"
-30 65-
-35 70-
-40 75-
-45 80-
-50 85—
-55 90-
TERTIARY SANTTACX) FORMATION (Tsa)
@ 60': Silty SANDSTONE: Trace of clay, light brown, moist, dense
Total Depth = 61.5 Feet
Ground water encountered at 16 feet at time of drilling
Backfllled with bentonite grout on 8/25/04
SAMPLE TYPES:
S SPUT SPOON
R RING SAMPLE
B BULK SAMPLE
T TUBE SAMPLE
G GRAB SAMPLE
SH SHELBY TUBE
TYPE OF TESTS:
OS DIRECTSHEAR
MO UAXIMUM DENSITY
CN CONSOUDATION
CR CORROSION
SA SIEVE ANALYSIS
AT ATTERBURG LIMITS
El EXPANSION INDEX
RV R-VALUE
LEIGHTON AND ASSOCIATES, INC.
GEOTECHNICAL BORING LOG B-2
Date 8-25-05
Project
Drilling Co.
SRM/State Street
Sheet 1 Of
Project No. 041742-001
West Hazmat Drilling Type of Rig Hollow-Stem Auger
Hole Diameter 8 in, Drive Weight 140 pound hammer Drop 30"
Elevation Top of Elevation 37' Location 2531 State Street
LU
a-a> •SO" S-O
W
w
•a B 2
<
o z « a E ra OT Q.
in
Cx-
0) u
oa
Be
OTO) oc so o
OT-^ WOT
_OT
'03
OT— Logged By
Sampled By
DESCRIPTION
DLN
DLN
OT «
O
"HT
35
30
10-
25
J5-
20
10
30-
I 117.1 11.9
AR nFICIAI. FILL (Afu)
@ 2': Silty CLAY: Dark brown, moist, soft
@ 5': Silty CLAY: Dark brown, moist, stiff
SM
SP
QUATE! @ 8'." Si lERNARY TERRACE DEPOSITS (Qt) illy SAND: Dark brown, moist, loose
@ 10': Fine to medium SAND: Brown, moist, medium dense
26 5.2
I
I
SM @ 15': Silty SAND: Dark brown, very moist, dense
51 118.8 7.6
50/6" CL
@ 20': Sandy CLAY; Dark gray-brown, moist, hard
@ 21': Silty SAND: Light brown, wet, dense
@ 24': Silty CLAY: Dark gray-brown, moist, dense
"SANflAGO KO"Rivl\"TTbN
50/4" 118.4 9.4 SM @25': Silty SANDSTONE: Light brown, wet, very dense
@ 28': Cjravel CONGLOMERATE: Light gray, moist, dense
DS
SAMPLE TYPES:
S SPLIT SPOON
R RING SAMPLE
B BULK SAMPLE
T TUBE SAMPLE
G GRAB SAMPLE
SH SHELBY TUBE
TYPE OF TESTS:
DS DIRECTSHEAR
MD MAXIMUM DENSITY
CN CONSOLIDATION
CR CORROSION
SA SIEVE ANALYSIS
AT ATTERBURG UMITS
El EXPANSION INDEX
RV R-VALUE 4 LEIGHTON AND ASSOCIATES, INC.
GEOTECHNICAL BORING LOG B-2
Date 8-25-05
SRM/State Street
Sheet 2 Of
Project No. 041742-001 Project
Drilling Co. West Hazmat Drilling Type of Rig Hollow-Stem Auger
Hole Diameter Sin. Drive Weight 140 pound hammer Drop 30"
Elevation Top of Elevation 37' Location 2531 State Street
•SO" S-O
OT » •o
B
-43
<
o z _» a
E ra to
CQtt
a.
in
0) u
Qa
B^
OT*
OC SO o
in^ 2W
_OT
OS
OT—
DESCRIPTION
Logged By
Sampled By
DLN
DLN
i2 w «> I-
w a >>
30-
35—
-10
50-
-15
55-
-20
60-
62 SM
SANIMGO FORMA"nON (Continued)
@ 30': Silty SANDSTONE: Light brown, moist, dense
I 50/6" 129.1 8.2 SC
I 50/6" SM
9 I 50/6" I 113.6 10.1 CL
@ 35': Silty SANDSTONE: Light brown, moist, vety dense
@ 36': Silty clayey SANDSTONE: Light gray, wet, dense
140": Silty SANDSTONE: Light brown, moist, very dense
) 43': Silty SANDSTONE: Dark gray, moist, dense
@ 45': Sandy CLAYSTONE: Dark brown, wet, hard
Total Depth = 48 Feet
Ground water encountered at 21 feet at time of drilling
Backfilled with tientonite grout on 8/25/05
SAMPLE TYPES:
S SPUTSPOON
R RING SAMPLE
B BULK SAMPLE
T TUBE SAMPLE
G GRAB SAMPLE
SH SHELBY TUBE
TYPE OF TESTS:
DS DIRECTSHEAR
MD MAXIMUM DENSITY
CN CONSOLIDATION
CR CORROSION
SA SIEVE ANALYSIS
AT ATTERBURG LIMITS
El EXPANSION INDEX
RV R-VALUE 4 LEIGHTON AND ASSOCIATES, INC.
041742-002
APPENDIX C
Laboratory Testinq Procedures and Test Results
Chloride Content: Chloride conient was tested in accordance with Caltrans Test Method CT422.
The results are presented below:
Sample Localion Chloride Content, ppm Chloride Attack Potential*
B-l {@2'-5' 639 Positive
B-2@8'-ll' 1,897 Severe
*per City of Scin Diego Program Guidelines for Design Consullant, 1992.
Direct Shear Tests: Direct shear tests were performed on selected undisturbed samples which were
soziked for a minimum of 24 hours under a surcharge equal lo the applied normal force during
testing. After transfer of the sample to the shear box and reloading of the sample, the pore pressures
sel up in the sample (due lo the transfer) were allowed to dissipate for a period of approximately
1 hour prior lo application of shearing force. The samples were tested under various normal loads
utilizing a motor-driven, strain-controlled, direct-shear testing apparatus at a strain rate of less
0.05 inches per minute. The test results are presented on the attached figures.
Moisture and Densitv Determination Tests: Moisture conlenl (ASTM Test Method D2216) and dry
density determinations were performed on relatively undisturbed ring samples obtained from the
lest borings and/or trenches. The results of these tests are presented in the boring and/or trench logs.
Where applicable, only the moisture content was determined firom disturbed samples.
Minimum Resistivity and pH Tests: Minimum resistivity and pH tests were performed in general
accordance with Caltrans Test Method CT643 for Steel or CT532 for concrete and standard
geochemical methods. The resuhs are presented in the table below:
Sample
Location Sample Description pH Minimum Resistivity
(ohms-cm)
E-\@y-w CL, Sandy Clay 8.33 1,821
B-2(g8'-n' Silty SAND (SM) 8.00 1,012
C-1
041742-002
APPENDIX C (Continued)
Soluble Sulfates: The soluble sulfate contents of selected samples were determined by siandard
geochemical methods (Caltrans Test Method CT417). The test results are presented in the table
below:
Sample Location Sample Description Sulfate
Content (%)
Potential Degree of
Sulfate Attack*
B-l (^2'-5' Sandy CLAY (CL) 0.06 Negligible
B-3@8'-ll' Silty SAND (SC) 0.045 Negligible
* Based on the 1997 edition of the Uniform Building Code, Table No. 19-A-4, prepared by the
Inlemalional Conference of Building Officials (ICBO, 1997).
Hydro-consolidation Tests: Hydro-consolidation tests were performed on selecled relatively
undisturbed ring samples. Samples were placed in a consolidometer and a load approximately equal
to the in-situ overburden pressure was applied. Waler was then added to the sample and the percent
hydro-consolidation for the load cycle was recorded as the ralio of the amount of vertical
compression to the original 1-inch heighl. The percent hydro-consolidation is presented on the
attached figure.
C-2
6000
5000
4000
in a
10
w
£ 3000
OT
k. ra
0)
OT
2000
1000
/
• ^
A/
7
1000 2000 3000 4000
Vertical Stress (psf)
5000 6000
Boring Location
Sample Depth (feet)
Sample Description
B-2 Defonnation Rate 0.05 In/min
15"
Brown Silty Sand (SM)
Average Strength Parameters
Peak Friction Angle. <t)'peak (deg) 47 Relaxed Friction Angle, <|)'„,„„j (deg)
Cohesion, c'peak (PSf)
46
^0.2 in. Friction Angle, fgo.r (deg)
Cohesion, c'@o.2" (psf)
900
47
Cohesion, C'reiaxed (PSO 350
800
DIRECT SHEAR SUMMARY Project No.
Project Name
041742-001
SRM/State Street
Leigitlon
Leighton and Associates, Inc.
One-Dimensional Swell or Settlement
Potential of Cohesive Soils
SRM / STATE STREET Project Name:
Project No.:
Boring No.:
Sample No.:
Sample Description: SM: BROWN SILTY SAND
041742-001
B-1
B-1-5.0
Initial Dry Density (pcf): 111.3
Initial Moisture (%): 12.2
Initial Length (in.): 1.0000
Initial Diai Reading: 0.0000
Diameter(ln): 2.416
(ASTM D 4546)
Tested By: BCC Date: 9/27/2005
Checked By: Date:
Sample Type: IN SITU
Depth (ft.) 5.0-6.5
Final Dry Density (pcf): 111.6
Final Moisture (%): 17.6
Initial Void ratio: 0.5149
Specific Gravity(assumed): 2.70
Initial Saturation (%) 63.8
Pressure (p)
(ksf)
Final Reading
(in)
Apparent
Thicl<ness
(in)
Load
Compliance
(%)
Swell (+)
Settlement (-)
% of Sample
Thickness
Void Ratio
Corrected
Deformation
(%)
0.27 0.0012 0.9988 0.00 -0.12 0.5131 -0.12
0.54 0.0024 0.9976 0.00 -0.24 0.5112 -0.24
H20 0.0027 0.9973 0.00 -0.27 0.5108 -0.27
Percent Swell / Settlement After Inundation = -0.03
Void Ratio - Log Pressure Curve
0.5200
re
OC
I
0.5100
0.100
Log Pressure (ksf)
1.000
COOAPSE-SWEa B-1
CALIFORNIA FAULT MAP
SRM / State Street
200 --
150 --
100
-100 --
-150
-200 --
Outl
* EQFAULT *
* *
version 3.00 *
******* if *****Jfft****r****
DETERMINISTIC ESTIMATION OF
PEAK ACCELERATION FROM DIGITIZED FAULTS
JOB NUMBER: 041742-001
DATE: 11-09-2005
lOB NAME: SRM / State street
CALCULATION NAME: Run # 1
FAULT-DATA-FILE NAME: C:\Progratn Fnes\EQFAULTl\CGSFLTE.DAT
SITE COORDINATES:
SITE LATITUDE: 33.1745
SITE LONGITUDE: 117.3700
SEARCH RADIUS: 100 mi
ATTENUATION RELATION: 6) Boore et al. (1997) Horiz. - vs = 400 m/s
UNCERTAINTY CM=Median, S=sigma): M Number of sigmas: 0.0
DISTANCE MEASURE: cd_2drp
SCOND: 0
Basement Depth: 5.00 km Campbell SSR: Campbell SHR:
COMPUTE PEAK HORIZONTAL ACCELERATION
FAULT-DATA FILE USED: C:\Program Files\EQFAULTl\CGSFLTE.DAT
MINIMUM DEPTH VALUE (km): 0.0
Page 1
outl
EQFAULT SUMMARY
DETERMINISTIC SITE PARAMETERS
Page 1
ESTIMATED MAX. EARTHQUAKE EVENT
APPROXIMATE
ABBREVIATED DISTANCE MAXIMUM 1 PEAK EST. SITE
FAULT NAME mi (km) EARTHQUAKE j SITE INTENSITY
MAG . (Mw) 1 ACCEL, g MOD.MERC.
NEWPORT-INGLEWOOD (Offshore) 3 7( 5 9) 'i .1 1 0 .407 x
ROSE CANYON 4 7( 7 6) 7 2 1 0 .382 X
CORONADO BANK 20 6( 33 1) 7 6 1 0 .176 VIII
ELSINORE (TEMECULA) 24 4( 39 2) 6 8 1 0 .101 VII
ELSINORE (JULIAN) 24 9( 40 1) 7 1 1 0 .117 VII
ELSINORE (GLEN IVY) 32 4( 52 1) 6 8 1 0 .081 VII
SAN JOAQUIN HILLS 32. 9( 53 0) 6 6 1 0 .088 VII
PALOS VERDES 33. 8( 54. 4) 7 3 1 0 .103 VII
NEWPORT-INGLEWOOD (L.A.Basin) 43. 8( 70 5) 7 1 1 0 .076 VII
CHINO-CENTRAL AVE. (Elsinore) 45. K 72. 6) 6 7 1 0 .073 VII
EARTHQUAKE VALLEY 45. 6( 73. 4) 6 5 1 0 .053 VI
SAN JACINTO-ANZA 46. 8( 75. 3) 7 2 1 0 .076 VII
SAN JACINTO-SAN JACINTO VALLEY 47. 0( 75. 7) 6 9 1 0 064 VI
WHITTIER 49. 4C 79. 5) 6 8 1 0 .059 VI
SAN JACINTO-COYOTE CREEK 53. 6( 86. 2) 6 6 1 0 050 VI
SAN JACINTO-SAN BERNARDINO 58. 7( 94. 5) 6 7 1 0 .049 VI
PUENTE HILLS BLIND THRUST | 59. 4( 95. 6) 7 1 0 073 VII
ELSINORE (COYOTE t^lOUNTAIN) ' 60. K 96. 7) 6 8 1 0 .051 VI
SAN ANDREAS - San Bernardino M-l 65. 2( 105. 0) 7 5 i 0 .069 VI
SAN ANDREAS - Whole M-la 65. 2( 105. 0) 8. 0 ' 0 089 VII
SAN ANDREAS - SB-Coach. M-lb-2 | 65. 2( 105. 0) 7 7 1 0 076 VII
SAN ANDREAS - SB-Coach. M-2b 65. 2( 105. 0), 7. 7 0 076 VII
SAN JOSE 66. 2( 106. 6) 6. 4 1 0 046 VI
SAN JACINTO - BORREGO 68. 0( 109. 5) 6. 6 0 041 V
CUCAMONGA 68. 8( 110. 8) 6 9 0 058 VI
SIERRA MADRE I 69. 0( 111. 0)i 7. 2 0 068 VI
PINTO MOUNTAIN 71. 5( 115. 1)1 7. 2 0 054 VI
SAN ANDREAS - Coachel1 a M-lc-5 73. 3( 118. 0)1 7. 2 0 053 VI
NORTH FRONTAL FAULT ZONE (West) | 73. 4( 118. 2)1 7. 2 0 065 VI
UPPER ELYSIAN PARK BLIND THRUST | 74. 8( 120. 4)i 6. 4 0 042 VI
CLEGHORN I 76. 2( 122. 7)1 6. 5 0 036 I V
RAYMOND 1 77. K 124. 1)1 6. 5 0 043 1 VI
Page 2
Outl
BURNT MTN. 1 77.2( 124 3)1 6 5 1 0.035 1 V
SAN ANDREAS - 1857 Rupture M-2a j 77.4( 124 6)1 7 8 1 0.070 1 VI
SAN ANDREAS - Cho-MOj M-lb-1 | 77.4( 124 6)1 7 8 1 0.070 1 VI
SAN ANDREAS - Mojave M-lC-3 1 77.4( 124 6)1 7 4 1 0.057 1 VI
CLAMSHELL-SAWPIT j 78.2( 125 9)1 6 5 1 0.043 1 VI
NORTH FRONTAL FAULT ZONE (East) i 79.2( 127 4)1 6 7 1 0.047 1 VI
VERDUGO 1 80.2( 129 0)1 6 9 1 0.052 1 VI
EUREKA PEAK j 80.5( 129 6)1 6 4 1 0.033 1 V
DETERMINISTIC SITE PARAMETERS
Page 2
ABBREVIATED
FAULT NAME
HOLLYWOOD
SUPERSTITION MTN. (San jacinto)
SANTA MONICA
LANDERS
HELENDALE - S. LOCKHARDT
ELMORE RANCH
SUPERSTITION HILLS (San Jacinto)
MALIBU COAST
LAGUNA SALADA
LENWOOD-LOCKHART-OLD WOMAN SPRGS
SIERRA MADRE (San Fernando)
NORTHRIDGE (E. Oak Ridge)
JOHNSON VALLEY (Northern)
ANACAPA-DUME
SAN GABRIEL
EMERSON So. - COPPER MTN.
BRAWLEY SEISMIC ZONE
********************************
APPROXIMATE
DISTANCE
mi (km)
82.1(
84.7(
86.2(
87.3(
87.6(
88.2(
89.3(
89.5(
91.5(
91.9(
93.1(
93.2(
94.7(
94.9(
94.9(
96.4(
96.9(
*********
132.
136
138.
140
140.
142.
143.
144.
147.
147.
149.
150.
152.
152.
152.
155.
156.
ESTIMATED MAX. EARTHQUAKE EVENT
*******
MAXIMUM
EARTHQUAKE
MAG.(Mw)
6.4
6.6
6.6
7.3
7.3
6.6
6.6
6.7
7.0
7.5
6.7
7.0
6.7
7.5
7.2
7.0
6.4
**********
PEAK
SITE
ACCEL, g
0T039~'
0.035
0.042
0.049
0.049
0.034
0.033
0.043
0.040
0.053
0.041
0.049
0.034
0.062
0.044
0.039
0.028
************
EST. SITE
INTENSITY
MOD.MERC.
V
V
VI
VI
VI
V
V
VI
V
VI
V
VI
V
VI
VI
V
V
*********
-END OF SEARCH-57 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS.
THE NEWPORT-INGLEWOOD (Offshore) FAULT IS CLOSEST TO THE SITE.
IT IS ABOUT 3.7 MILES (5.9 km) AWAY.
LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.4072 g
Page 3
Out2
***********************
* *
* EQFAULT *
* *
* version 3.00 *
* *
***********************
DETERMINISTIC ESTIMATION OF
PEAK ACCELERATION FROM DIGITIZED FAULTS
JOB NUMBER: 041742-001
DATE: 11-09-2005
JOB NAME: SRM / State street
CALCULATION NAME: Run # 1
FAULT-DATA-FILE NAME: C:\Program Files\EQFAULTl\CGSFLTE.DAT
SITE COORDINATES:
SITE LATITUDE: 33.1745
SITE LONGITUDE: 117.3700
SEARCH RADIUS: 100 mi
ATTENUATION RELATION: 6) Boore et al. (1997) Horiz. - Vs = 400 m/s
UNCERTAINTY (M=Median, s=Sigma): s Number of Sigmas: 1.0
DISTANCE MEASURE: cd_2drp
SCOND: 0
Basement Depth: 5.00 km Campbell SSR: Campbell SHR:
COMPUTE PEAK HORIZONTAL ACCELERATION
FAULT-DATA FILE USED: C:\Program Files\EQFAULTl\CGSFLTE.DAT
MINIMUM DEPTH VALUE (km): 0.0
Page 1
Out2
EQFAULT SUMMARY
DETERMINISTIC SITE PARAMETERS
Page 1
ESTIMATED MAX. EARTHQUAKE EVENT
APPROXIMATE
ABBREVIATED DISTANCE MAXIMUM PEAK EST. SITE
FAULT NAME mi (km) EARTHQUAKE SITE INTENSITY
MAG. (Mw) ACCEL, g MOD.MERC.
NEWPORT-INGLEWOOD (Offsiiore) 3 7( sTg) 7.1 0.685 XI
ROSE CANYON 4 7( 7.6) 7.2 0.643 X
CORONADO BANK 20 6( 33.1) 7.6 0.295 IX
ELSINORE (TEMECULA) 24 4( 39.2) 6.8 0.170 VIII
ELSINORE (JULIAN) 24 9( 40.1) 7.1 0.196 VIII
ELSINORE (GLEN IVY) 32 4( 52.1) 6.8 0.137 VIII
SAN JOAQUIN HILLS 32 9( 53.0) 6.6 0.148 VIII
PALOS VERDES 33 8( 54.4) 7.3 0.172 VIII
NEWPORT-INGLEWOOD (L.A.Basin) 43 8( 70.5) 7.1 0.127 VIII
CHINO-CENTRAL AVE. (Elsinore) 45 1( 72.6) 6.7 0.122 VII
EARTHQUAKE VALLEY 45 6( 73.4) 6.5 0.090 VII
SAN JACINTO-ANZA 46 8( 75.3) 7.2 0.127 VIII
SAN JACINTO-SAN JACINTO VALLEY 47 0( 75.7) 6.9 0.108 VII
WHITTIER 49 4( 79.5) 6.8 0.099 VII
SAN JACINTO-COYOTE CREEK 53 6( 86.2) 6.6 0.084 VII
SAN JACINTO-SAN BERNARDINO 58 7( 94.5) 6.7 0.082 VII
PUENTE HILLS BLIND THRUST 59 4( 95.6) 7.1 0.122 VII
ELSINORE (COYOTE MOUNTAIN) 60 1( 96.7) 6.8 0.085 VII
SAN ANDREAS - San Bernardino M-l 65 2( 105.0) 7.5 0.115 VII
SAN ANDREAS - Whole M-la 65 2( 105.0) 8.0 0.150 VIII
SAN ANDREAS - SB-Coach. M-lb-2 65 2( 105.0) 7.7 0.128 VIII
SAN ANDREAS - SB-Coach. M-2b 65 2( 105.0) 7.7 0.128 VIII
SAN JOSE 66 2( 106.6) 6.4 0.078 VII
SAN JACINTO - BORREGO 68. 0( 109.5) 6.6 0.069 VI
CUCAMONGA ' 68 8( 110.8) 6.9 0.098 VII
SIERRA MADRE 69. 0( 111.0) 7.2 0.115 VII
PINTO MOUNTAIN 71. 5( 115.1) 7.2 0.092 VII
SAN ANDREAS - coachella M-lc-5 1 73. 3( 118.0) 7.2 0.090 VII
NORTH FRONTAL FAULT ZONE (West) | 73. 4( 118.2) 7.2 0.109 VII
UPPER ELYSIAN PARK BLIND THRUST | 74. 8( 120.4) 6.4 0.071 VI
CLEGHORN 76. 2( 122.7) 6.5 0.060 VI
RAYMOND 1 77. 1( 124.1) 6.5 0.073 VII
Page 2
Out2
BURNT MTN.
SAN ANDREAS - 1857 RUptUTC M-2a
SAN ANDREAS - Cho-Moj M-lb-1
SAN ANDREAS - Mojave M-lC-3
CLAMSHELL-SAWPIT
NORTH FRONTAL FAULT ZONE (East)
VERDUGO
EUREKA PEAK
77.2( 124.3)1 6 5 1 0 060 1 VI
77.4( 124.6)1 7 8 1 0 118 1 VII
77.4( 124.6)1 7 8 1 0 118 1 VII
77.4( 124.6)1 7 4 1 0 096 1 VII
78.2( 125.9)1 6 5 1 0 072 1 VI
79.2( 127.4)1 6 7 1 0 079 1 VII
80.2( 129.0)1 6 9 1 0 087 1 VII
80.5( 129.6)1 6 4 1 0 055 1 VI
DETERMINISTIC SITE PARAMETERS
Page 2
APPROXIMATE
ABBREVIATED DISTANCE MAXIMUM PEAK EST. SITE
FAULT NAME mi (km) EARTHQUAKE SITE INTENSITY
MAG (Mw) ACCEL, g MOD.MERC.
HOLLYWOOD 82 • K 132. 1) 6 4 0 .066 VI
SUPERSTITION MTN. (San Jacinto) 84 .7( 136. 3) 6 6 0 .059 VI
SANTA MONICA 86 .2( 138. 7) 6 6 0 .070 VI
LANDERS 87 .3( 140. 5) 7 3 0 .083 VII
HELENDALE - S. LOCKHARDT 87 .6( 140. 9) 7 3 0 .083 VII
ELMORE RANCH 88 .2( 142. 0) 6 6 0 .057 VI
SUPERSTITION HILLS (San Jacinto) 89 .3( 143. 7) 6 6 0 .056 VI
MALIBU COAST 89 .5( 144. 1) 6 7 0 .072 VI
LAGUNA SALADA 91 .5( 147. 2) 7 0 0 .068 VI
LENWOOD-LOCKHART-OLD WOMAN SPRGS 91 .9( 147. 9) 7 5 0 .088 VII
SIERRA MADRE (San Fernando) 93 .K 149. 9) 6 7 0 .070 VI
NORTHRIDGE (E. Oak Ridge) 93 .2( 150. 0) 7 0 0 .082 VII
JOHNSON VALLEY (Northern) 94 .7( 152. 4) 6 7 0 057 VI
ANACAPA-DUME 94 .9( 152. 7) 7 5 0 .105 VII
SAN GABRIEL 94 .9( 152. 8) 7 2 0 074 VII
EMERSON So. - COPPER MTN. 96 .4( 155. 1) 7 0 0 .065 VI
BRAWLEY SEISMIC ZONE 96 .9( 156. 0) 6 4 0 047 VI
ESTIMATED MAX. EARTHQUAKE EVENT
*******************************************************************************
-END OF SEARCH-57 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS.
THE NEWPORT-INGLEWOOD (Offshore) FAULT IS CLOSEST TO THE SITE.
IT IS ABOUT 3.7 MILES (5.9 km) AWAY.
LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.6850 g
Page 3
Leigiiton and Associates,Inc.
GENERAL E ARTHVVORK AND GRADING SPECIFICATIONS
Page 1 of 6
LEIGHTON AND ASSOCIATES, INC.
GENERAL EARTHWORK AND GRADING SPECIFICATIONSFOR ROUGH GRADING
1.0 General
1.1 Intent: These General Earthwork and Grading Specifications are for the grading and
earthwork shown on the approved grading plan(s) and/or indicated in the geotechnical
report(s). These Specifications are a part of the recommendations contained in the
geotechnical report(s). In case of conflict, the specific recommendations in the
geotechnical report shall supersede these more general Specifications. Observations of the
earthwork by the project Geotechnical Consultant during the course of grading may result
in new or revised recommendations that could supersede these specifications or the
recommendations in the geotechnical report(s),
1.2 The Geotechnical Consultant of Record: Prior to commencementof work, the owner shall
employ the Geotechnical Consultant of Record (Geotechnical Consultant). The
Geotechnical Consultants 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 commencementof the grading.
Prior to commencement of grading, the Geotechnical Consultant shall review the "work
plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel
to perform the appropriate level of observation, mapping, and compaction testing.
During the grading and earthwork operations, the Geotechnical Consultant shall observe,
map, and document the subsurface exposures to verify the geotechnical design
assumptions. If the observed conditions are found to be significantly different than the
interpreted assumptions during the design phase, the Geotechnical Consultant shall infonn
the owner, recommend appropriate changes in design to accommodate the observed
conditions, and notify the review agency where required. Subsurface areas to be
geotechnically observed, mapped, elevations recorded, and/or tested include natural ground
after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial
removal" areas, all key bottoms, and benches made on sloping ground to receive fill.
The Geotechnical Consultant shall observe the moisture-conditioningand processing of the
subgrade and fill materials and perfonn relative compaction testing of fill to detennine the
attained level of compaction. The Geotechnical Consultant shall provide the test results to
the owner and the Contractor on a routine and frequent basis.
3030.109<l
Leightonand Associates,Inc.
GENERAL EARTH WORK AND GRADING SPECIFICATIONS
Page 2 of 6
1.3 The Earthwork Contractor: The Earthwork Contractor (Contractor) shall be qualified,
experienced, and knowledgeable in earthwork logistics, preparation and processing of
ground to receive fill, moisture-conditioningand processing of fill, and compacting fill.
The Contractor shall review and accept the plans, geotechnical report(s), and these
Specifications prior to commencement of grading. The Contractor shall be solely
responsible for performing the grading in accordance with the plans and specifications.
The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a
work plan that indicates the sequence of earthwork grading, the number of "spreads" of
work and the estimated quantities of daily earthwork contemplated for the site prior to
commencementof grading. The Contractor shall inform the owner and the Geotechnical
Consultant of changes in work schedules and updates to the work plan at least 24 hours in
advance of such changes so that appropriate observations and tests can be planned and
accomplished. The Contractor shall not assume that the Geotechnical Consultant is aware
of all grading operations.
The Contractor shall have the sole responsibility to provide adequate equipment and
methods to accomplish the earthwork in accordance with the applicable grading codes and
agency ordinances, these Specifications, and the recommendations in the approved
geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical
Consultant, unsatisfactorj'conditions, such as unsuitable soil, improper moisture condition,
inadequate compaction, insufficient buttress key size, adverse weather, etc., are resuhing in
a quality of work less than required in these specifications, the Geotechnical Consultant
shall reject the work and may recommend to the owner that construction be stopped until
the conditions are rectified.
2.0 Preparation of Areas to be Filled
2.1 Clearing and Grubbing: Vegetation, such as brush, grass, roots, and other deleterious
material shal! be sufficiently removed and properly disposed of in a method acceptable to
the owner, governing agencies, and the Geotechnical ConsultanL
The Geotechnical Consultant shall evaluate the extent of these removals depending on
specific site conditions. Earth fill material shall not contain more than 1 percent of organic
materials (by volume). No fill lift shall contain more than 5 percent of organic matter.
Nesting of the organic materials shall not be allowed.
If potentially hazardous materials are encountered, the Contractor shall stop work in the
affected area, and a hazardous material specialist shall be informed immediately for proper
evaluation and handlingof these materials prior to continuingto work in that area.
As presently defmed by the State of California, most refined petroleum products (gasoline,
diesel fuel, motor oil, grease, coolant, etc) have chemical constituents that are considered
to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids
onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment,
and shall not be allowed.
3030.1094
Leightonand Associates.Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 3 of 6
2.2 Processing: Existing giound that has been declared satisfactory for support of fill by the
Geotechnical Consultant shall be scarified to a minimum depth of 6 inches. Existing
ground that is not satisfactory sha 11 be overexcavated as specified in the following section.
Scarification shall continue until soils are broken down and free of large clay lumps or
clods and the working surface is reasonably uniform, flat, and free of uneven features that
would inhibit uniform compaction.
2.3 Overexcavation: In addition to removals and overexcavations recommended in the
approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy,
organic-rich, highly fractured or otherwise unsuitable ground shall be overexcavated to
competent ground as evaluated bythe Geotechnical Consultant during grading.
2.4 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal
to vertical units), the ground shall be stepped or benched. Please see the Standard Details
for a graphic illustration. The lowest bench or key shall be a minimum of 15 feet wide and
at least 2 feet deep, into competent material as evaluated by the Geotechnical Consultant.
Other benches shall be excavated a minimum height of 4 feet into competent material or as
otherwise recommended by the Geotechnical Consultant. Fill placed on ground sloping
flatter than 5:1 shall also be benched or otherwise overexcavated to provide a flat subgrade
for the fill.
2.5 Evaluation/Acceptance of Fill Areas: All areas to receive fill, including removal and
processed areas, key bottoms, and benches, shall be observed, mapped, elevations
recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable
to receive fill. The Contractor shall obtain a written acceptance from the Geotechnical
Consultant prior to fill placement. A licensed surveyor shall provide the survey control for
determ ining elevations of processed areas, keys, and benches.
3.0 Fill Material
3.1 General: Material to be used as fill shall be essentially free of organic matter and other
deleterious substances evaluated and accepted by the Geotechnical Consultant prior lo
placement. Soils of poor quality, such as those with unacceptable gradation, high
expansion potential, or low strength shall be placed in areas acceptable to the Geotechnical
Consultant or mixed with other soils to achieve satisfactory fill material.
3.2 Oversize: Oversize material defined as rock, or other irreducible material with a maximum
dimension greater than 8 inches, shall not be buried or placed in fill unless location,
materials, and placement methods are specifically accepted by the Geotechnical
Consultant. Placement operations shall be such that nesting of oversized material does not
occur and such that oversize material is completely surrounded by compacted or densified
fill. Oversize material shall not be placed within 10 vertical feet of finish grade or within
2 feet of future utilities or underground construction.
3030.1094
Leightonand Associates,Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 4 of 6
3.3 Import: If importing of fill material is required for grading, proposed import material shall
meet the requirements of Section 3.1. The potential import source shall be given to the
Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that
its suitability can be determined and appropriate tests performed.
4.0 Fill Placement and Compaction
4.1 Fill Layers: Approved fill material shall be placed in areas prepared to receive fill (per
Section 3.0) in near-horizontal layers not exceeding 8 inches in loose thickness. The
Geotechnical Consultant may accept thicker layers if testing indicates the grading
procedures can adequately compact the thicker layers. Each layer shall be spread evenly
and mixed thoroughly to attain relative uniformity of material and moisture throughout.
4.2 Fill Moisture Conditioning: Fill soils shall be watered, dried back, blended, and/or mixed,
as necessary to attain a relatively uniform moisture content at or slightly over optimum.
Maximum density and optimum soil moisture content tests shall be performed in
accordance with the American Society of Testing and Materials (ASTM Test Method
D1557-9I).
4.3 Compaction of Fill: After each layer has been moisture-conditioned, mixed, and evenly
spread, it shall be uniformly compacted to not less than 90 percent of maximum dry density
(ASTM Test Method D1557-91), Compaction equipment shall be adequately sized and be
either specifically designed for soil compaction or of proven reliability to efficiently
achieve the specified level of compaction with unifonnity.
4.4 Compaction of Fill Slopes: In addition to normal compaction procedures specified above,
compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot
rollers at increments of 3 to 4 feet in fill elevation, or by other methods producing
satisfactory results acceptable to the Geotechnical Consultant. Upon completion of
grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of
maximum density per ASTM Test Method Dl 557-91.
4.5 Compaction Testing: Field tests for moisture content and relative compaction of the fill
soils shall be performed by the Geotechnical Consultant. Location and frequency of tests
shall be at the Consultant's discretion based on field conditions encountered. Compaction
test locations will not necessarily be selected on a random basis. Test locations shall be
selected to verify adequacy of compaction levels in areas that are judged to be prone to
inadequate compaction (such as close to slope faces and at the fil I/bedrock benches).
3030.1094
Leightonand Associates,Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIO.NS
Page 5 of 6
4.6 Frequencv of Compaction Testing: Tests shall be taken at intervals not exceeding2 feet in
vertical rise and/or 1,000 cubic yards of compacted fill soils embankment. In addition, as a
guideline, at least one test shall be taken on slope faces for each 5,000 square feet of slope
face and/or each 10 feet of vertical height of slope. The Contractor shall assure that fill
construction is such that the testing schedule can be accomplished by the Geotechnical
Consultant. The Contractor shall stop or slow down the earthwork construction if these
minimum standards are not met.
4.7 Compaction Test Locations: The GeotechnicalConsultantshall document the approximate
elevation and horizontal coordinates of each test location. The Contractor shall coordinate
with the project surveyor to assure that sufficient grade stakes are established so that the
Geotechnical Consultant can determine the test locations with sufficient accuracy. At a
minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than
5 feet apart from potential test locations shall be provided.
5.0 Subdrain Installation
Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the
grading plan, and the Standard Details. The Geotechnical Consultant may recommend additional
subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions
encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for
line and grade after installation and prior to burial. Sufficient time should be allowed by the
Contractor for these surveys.
6.0 Excavation
Excavations, as well as over-excavation for remedial purposes, shall be evaluated by the
Geotechnical Consullant during grading. Remedial removal depths shown on geotechnical plans
are estimates only. The actual extent of removal shall be determined by the Geotechnical
Consultant based on the field evaluation of exposed conditions during grading. Where fill-over-cut
slopes are to be graded, the cut portion of the slope shall be made, evaluated, and accepted by the
Geotechnical Consultant prior to placement of matertals for construction of the fill portion of the
slope, unless otherwise recommended by the Geotechnical ConsultanL
3030.1094
Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 6 of 6
7.0 Trench Backfills
7.1 The Contractor shall follow all OHSA and Cal/OSHA requirements for safety of trench
excavations.
7.2 All bedding and backfill of utility trenches shall be done in accordance with the applicable
provisions of Standard Specifications of Public Works Construction. Bedding material
shall have a Sand Equivalent greater than 30 (SE>30), The bedding shall be placed to 1
foot over the top of the conduit and densified by jetting. Backfill shall be placed and
densified to a minimum of 90 percent of maximum from 1 foot above the top of the
conduit to the surface,
7.3 The jetting of the bedding around the conduits shall be observed by the Geotechnical
Consultant,
7.4 The Geotechnical Consultant shall test the trench backfill for relative compaction. At least
one test should be made for evei^ 300 feet of trench and 2 feet of fill.
7.5 Lift thickness of trench backfill 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 relative
compaction by his alternative equipment and method.
3030.1094
FILL SLOPE
PROJECTED PLANE
1 TO 1 MAXIMUM FROM
TOE OF SLOPE TO
APPROVED GROUND
EXISTING
GROUND SURFACE
BENCH HEIGHT
(4" TYPICAL)
REMOVE
UNSUITABLE
MATERIAL
2' MIN,-
KEY
DEPTH
LOWEST
BENCH
(KEY)
niL-OVER-CUT SLOPE
EXISTING
GROUND SURFACE
OMPACTED:-:-:-:>r "":=FiLL--:jS:: '
Wm
—qmnF"^
BENCH I LBENCH HEIGHT
(4' TYPICAL)
REMOVE
UNSUITABLE
MATERIAL
CUT-OVER-niL SLOPE
OVERBUILD AND
TRIM BACK
-CUT FACE
SHALL BE CONSTRUCTED PRIOR
TO FILL PLACEMENT TO ASSURE
ADEQUATE GEOLOGIC CONDITIONS
EXISTING-
GROUND __.
SURFACE ^0:-^^.-
/yy.-y:
PROJECTED PLANE
1 TO 1 MAXIMUM
FROM TOE OF SLOPE
TO APPROVED GROUND
2' MIN
KEY
DEPTH
UT FACE SHALL BE
CONSTRUCTED PRIOR
TO FILL PLACEMENT
REMOVE
UNSUITABLE
MATERIAL
BENCH HEIGHT
(4' TYPICAL)
FOR SUBDRAINS SEE
STANDARD DETAIL C
LOWEST
BENCH
(KEY)
BENCHING SHALL BE DONE WHEN SLOPE'S
ANGLE IS EOUAL TO OR GREATER THAN 5:1.
MINIMUM BENCH HEIGHT SHALL BE 4 FEET
ANO MINIMUM FILL WIDTH SHALL BE 9 FEET
KEYING AND BENCHING
GENERAL EARTHWORK AND
GRADING SPECIFICATIONS
STANDARD DETAILS A
LEIGHTON AND ASSOCIATES
FINISH GRADE
SLOPE FACE
• OVERSIZE ROCK IS LARGER THAN
8 INCHES IN LARGEST DIMENSION.
• EXCAVATE A TRENCH IN THE COMPACTED
FILL DEEP ENOUGH TO BURY ALL THE
ROCK.
• BACKFILL WITH GRANULAR SOIL JETTED
OR FLOODED IN PLACE TO FILL ALL THE
VOIDS.
• DO NOT BURY ROCK WITHIN 10 FEET OF
FINISH GRADE.
• WINDROW OF BURIED ROCK SHALL BE
PARALLEL TO THE FINISHED SLOPE.
GRANULAR MATERIAL TO BE'
DENSIFIED IN PLACE BY
FLOODING OR JETTING.
DETAIL
"JETTED OR FLOODED
GRANULAR MATERIAL
TYPICAL PROFILE ALONG WINDROW
OVERSIZE
ROCK DISPOSAL
GENERAL EARTHWORK AND
GRADING SPECIFICATIONS
STANDARD DETAILS B
LEIGHTON ANO ASSOCIATES
N
-EXISTING
GROUND SURFACE 4
/
/
/ /
BENCHING-
REMOVE
UNSUITABLE
MATERIAL
SUBDRAIN
TRENCH
SEE DETAIL BELOW
CALTRANS CLASS 2 PERMEABLE
OR jSI2 ROCK (9FT'^J/FT) WRAPPED
IN FILTER FABRIC //
FILTER FABRIC
(MIRAFI UON OR APPROVED
EQUIVALENT)'
4" MIN. BEDDING
COLLECTOR PIPE SHALL
BE MINIMUM 6" DIAMETER
SCHEDULE 40 PVC PERFORATED
PIPE. SEE STANDARD DETAIL D
FOR PIPE SPECIFICATIONS
SUBDRAIN DETAIL
DESIGN FINISH
GRADE
NONPERFORATED 6 0 MIN 6" 0MIN, PIPE
FILTER FABRIC
(MIRAFI MON OR APPROVED
EQUIVALENT)
CALTRANS CLASS 2 PERMEABLE
OR #2 ROCK (9FT''3/FT) WRAPPED
IN FILTER FABRIC
DETAIL QF CANYON SUBDRAIN OUTLET
CANYON SUBDRAINS GENERAL EARTHWORK AND
GRADING SPECIFICATIONS
STANDARD DETAILS C
LEIGHTON ANO ASSOCIATES
15' MIN.
OUTLET PIPES
4" 0 NONPERFORATED PIPE,
100' MAX. O.C. HORIZONTALLY,
30' MAX O.C. VERTICALLY
BACK CUT
1:1 OR FLATTER
•SEE SUBDRAIN TRENCH
DETAIL
LOWEST SUBDRAIN SHOULD
BE SITUATED AS LOW AS
POSSIBLE TO ALLOW
SUITABLE OUTLET
-KEY DEPTH
(2' MIN.)
KEY WIDTH
AS NOTED ON GRADING PLANS
(15' MIN.) OVERLAP 12 MIN
FROM THE TOP HOG
RING TIED EVERY
6 FEET
CALTRANS CLASS
PERMEABLE OR #2
ROCK (3 FT'^3/FT)
WRAPPED IN FILTER
FABRIC
r-4" 0
\ NON-PERFORATED
\ OUTLET PIPE
PROVIDE POSITIVE
SEAL AT THE
JOINT
T-CONNECTION
FOR COLLECTOR
PIPE TO OUTLET PIPE
6 MIN.
COVER
FILTER FABRIC
ENVELOPE (MIRAFI
140 OR APPROVED
EQUIVALENT)
4" 0
PERFORATED
PIPE
-4 MIN.
BEDDING
SUBDRAIN TRENCH DETAIL
SUBDRAIN INSTALLATION - subdroin collector pipe shall be installed with perforation down or,
unless otherwise designated by the geotechnical consultant. Outlet pipes shall be non-perforoted
pipe. The subdroin pipe shell hove ot leost 8 perforations uniformly spoced per foot. Perforation
sholl be 1/4" to 1/2" if drill holes ore used. All subdroin pipes sholl tiove a grodient of ot
least 2% towards the outlet.
SUBDRAIN PIPE - Subdroin pipe sholl be ASTM D2751. SDR 23.5 or ASTM D1527.
ASTM D3034, SDR 23.5. Schedule AO Polyvinyl Chloride Plostic (PVC) pipe.
Schedule 40, or
All outlet pipe sholl be placed in o trencti no wide thon twice the subdroin pipe. Pipe sholl be in
soil of SE >/=30 jetted or flooded in ploce except for the outside 5 feet which sholl be notive
soil bockfill.
BUTTRESS OR
REPLACEMENT FILL
SUBDRAINS
GENERAL EARTHWORK AND
GRADING SPECIFICATIONS
STANDARD DETAILS D
LEIGHTON ANO ASSOCIATES
SOIL BACKFILL, COMPACTED TO
90 PERCENT RELATIVE COMPACTION
BASED ON ASTM D1557
RETAINING WALL
WALL WATERPROOFING
PER ARCHITECTS
SPECIFICATIONS
WALL FOOTING
FILTER FABRIC ENVELOPE
(MIRAFI MON OR APPROVED
EQUIVALENT)"
3/4" TO 1-1/2" CLEAN GRAVEL
4" (MIN.) DIAMETER PERFORATED
PVC PIPE (SCHEDULE 40 OR
EQUIVALENT) WITH PERFORATIONS
ORIENTED DOWN AS DEPICTED
MINIMUM 1 PERCENT GRADIENT
TO SUITABLE OUTLET
COMPETENT BEDROCK OR MATERIAL
AS EVALUATED BY THE GEOTECHNICAL
CONSULTANT
NOTE; UPON REVIEW BY THE GEOTECHNICAL CONSULTANT.
COMPOSITE DRAINAGE PRODUCTS SUCH AS MIRADRAIN OR
J-DRAIN MAY BE USED AS AN ALTERNATIVE TO GRAVEL OR
CLASS 2 PERMEABLE MATERIAL. INSTALLATION SHOULD BE
PERFORMED IN ACCORDANCE WITH MANUFACTURER'S
SPECIFICATIONS.
RETAINING WALL
DRAINAGE DETAIL
GENERAL EARTHWORK AND
GRADING SPECIFICATIONS
STANDARD DETAILS E
LEIGHTON AND ASSOCIATES