HomeMy WebLinkAboutCT 02-12; CARLSBAD OFFICE CAMPUS; GEOTECHNICAL INVESTIGATION; 2001-04-02-:1
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Leighton and Associates
GEOTECHNICAL CONSULTANTS
CT02-lY
GEOTECHNICAL INVESTIGATION,
PROPOSED CARLSBAD OFFICE CAMPUS,
5600 A VENIDA ENCINAS
CARLSBAD, CALIFORNIA
Project No. 040382-001
April 2, 2001
Prepared For
CARLTASDEVELOPMENT
5600 Avenida Encinas, Suite 100
Carlsbad, California 92008
3934 Murphy Canyon Road, #8205, San Diego, CA 92123-4425
(858) 292-8030 • FAX (858) 292-0771 • www.ieightongeo.com
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~ ::------. -.:: Leighton and Associates
1961 -2001
To:
Attention:
April 2, 2001
Carltas Development
5600 A venida Encinas, Suite 100
Carlsbad, California 92008
Mr. John White
GEOTECHNICAL CONSULTANTS
Project No. 040382-00 I
Subject: Geotechnical Investigation, Proposed Carlsbad Office Campus, 5600 A venida Encinas,
Carlsbad, California
In accordance with your request and authorization, we have conducted a geotechnical investigation of the
proposed Carlsbad Office Campus located at 5600 Avenida Encinas, Carlsbad, California (see Site
Location Map -Figure I). Based on the results of our study, it is our opinion that the development of the
site is feasible provided the recommendations provided herein are incorporated into the design and
construction of the proposed improvements. The accompanying report presents a summary of our
current investigation 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 office. We
appreciate this opportunity to be of service.
Respectfully submitted,
LEIGHTON AND ASSOCIATES, INC.
Adam Terronez
Senior Staff EngineerlProject Manager
Timothy 1. Lawson, RCE 53388
Consulting Engineer
Distribution: (6) Addressee
3934 Murphy Canyon Road, #8205, San Diego, CA 92123-4425
(858) 292-8030 • FAX (858) 292-0771 • www.leightongeo.com
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TABLE OF CONTENTS
Section
1.0 INTRODUCTION ............................................................................................................................................... 1
1.1 PURPOSE AND SCOPE ....................................................................................................................................... 1
1.2 SITE LOCATION AND DESCRlPTION .................................................................................................................. 1
1.3 PROPOSED DEVELOPMENT .............................................................................................................................. 2
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING .............................................................. 4
3.0 SUMMARY OF GEOTECHNICAL CONDITIONS ........................................................................................ 5
3.1 GEOLOGY ........................................................................................................................................................ 5
3.1.1 Artificial Fill Soils ................................................................................................................................. 5
3.1.2 Residual Soils ........................................................................................................................................ 5
3.1.3 Terrace Deposits ................................................................................................................................... 5
3.1.4 Santiago Formation .............................................................................................................................. 6
3.2 SURFACE AND GROUND WATER ...................................................................................................................... 6
4.0 FAULTING AND SEISMICITY ......................................................................................................................... 7
4.1 FAULTING ........................................................................................................................................................ 7
4.2 SEISMICITY ...................................................................................................................................................... 7
4.2.1 Shallow Ground Rupture .............................................................................................. : ....................... 8
4.2.2 Liquefaction .......................................................................................................................................... 8
4.2.3 Earthquake-Induced Settlement ............................................................................................................ 9
4.2.4 Lateral Spread ...................................................................................................................................... 9
4.2.5 Tsunamis and Seiches ........................................................................................................................... 9
5.0 CONCLUSIONS ................................................................................................................................................ 10
6.0 RECOMMENDA TIONS .................................................................................................................................... 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 ..................................................................................................... : .......... 13
6.1.4 Fill Placement and Compaction ......................................................................................................... 13
6.1.5 Transition Mitigation .......................................................................................................................... 13
6.1.6 Expansive Soils and Selective Grading ............................................................................................... 14
6.1.7 Import Soils ......................................................................................................................................... 14
6.2 SURFACE DRAINAGE AND EROSION ............................................................................................................... 14
6.3 FOUNDATION AND SLAB CONSIDERATIONS ................................................................................................ : .. 14
6.3.1 Foundations ........................................................................................................................................ 14
6.3.2 Slabs .................................................................................................................................................... 15
6.3.3 Settlement ............................................................................................................................................ 16
6.3.4 Designfor Expansive Soils ................................................................................................................. 16
6.3.5 Lateral Pressures and Shoring Design ............................................................................................... 16
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TABLE OF CONTENTS
Section Page
6.4 GEOCHEMICAL CONSIDERATIONS ...........................•.........•......................•.................................................... 18
6.5 PRELIMINARY PAVEMENT DESIGN ................................................................................................................ 18
6.6 CONSTRUCTION OBSERVATION AND PLAN REVIEW ........•................•............•.••.•....................................•..... 19
7.0 LIMITATIONS ................................................................................................................................................... 20
TABLES
TABLE I-SEISMICPARAMETERSFORACTIVEFAULTS -PAGE7
TABLE 2 -STATIC EQUIVALENT FLUID WEIGHT (PCF) -PAGE 17
TABLE 3 -PRELIMINARY PAVEMENT DESIGN SECTIONS, R-VALUE = 21 -PAGE 19
FIGURES
FIGURE 1 -SITE LOCATION MAP -PAGE 3
FIGURE 2 -BORING LOCATION MAp -REAR OF TEXT
ApPENDICES
ApPENDIX A -REFERENCES
ApPENDIX B -BORING LOGS
ApPENDIX C -LABORATORY TESTING PROCEDURES AND TEST RESULTS
ApPENDIX D -GENERAL EARTHWORK AND GRADING SPECIFICATIONS
ApPENDIX E -SEISMIC ANALYSIS
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040382-001
1.0 INTRODUCTION
Purpose and Scope
This report presents the results of our geotechnical investigation at the site of the proposed
Carlsbad Office Campus development. The purpose of our investigation was to identify and
evaluate the existing significant geotechnical conditions present at the site and to provide
preliminary conclusions and geotechnical recommendations relative to the proposed
development. Our scope of services included:
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Review of available pertinent, published and unpublished geotechnical literature and maps
(Appendix A).
A geotechnical reconnaissance and geologic mapping of site conditions.
Coordination with Underground Service Alert.
Subsurface exploration consisting of the excavation, logging, and sampling of six holIow-
stem borings. The logs of the borings are presented in Appendix B.
Laboratory testing of representative soil samples obtained from the subsurface exploration
program. Results of these tests are presented in Appendix C, and are noted on the boring
logs (Appendix B).
Compilation and analysis of the geotechnical data obtained from the field investigation and
laboratory testing.
Preparation of this report presenting our findings, conclusions, and geotechnical
recommendations with respect to the proposed design, site grading, and general construction
considerations.
Site Location and Description
The proposed project site is located at 5600 A vendia Encinas and is located northwest of the
intersection of Palomar Airport Road and Avenida Encinas in Carlsbad, California (Figure 1,
Page 3). Presently, an existing commercial and office-type building and associated parking
improvements are located at the site. In addition, several existing underground utilities also
occupy portions of the site.
The site is bordered by several commercial buildings to the south, Avendia Encinas to the east,
an existing drainage channel to the north, and railroad tracks to the west. Topography of the site
is generally flat with elevations ranging from approximately 52 feet mean sea level (msl) along
the eastern portion of the site to approximately 47 feet msl along the western portion of the site.
Surface drainage on the site generally consists of gently sloping paved areas that grades to
existing catch basins. In addition, drainage swales are located along the western portion of the
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040382-001
southern property line and west of the site. Landscaped grass, trees, shrubs and concrete flatwork
are also located at intermittent areas across the site.
Proposed Development
It is our understanding that the proposed development will include the construction of four
3-story office-type structures located at the eastern portion of the site and one 2-level parking
structure (with one level below grade) located along the western portion of the site. Associated
retaining walls, at-grade parking, concrete flatwork, and landscaping are also anticipated within
the proposed development. In addition, we anticipate demolition of the existing structure and
underground utilities.
Finish floor elevations for the proposed structures, preliminary foundation designs or structural
loads were not provided prior to the preparation of this report. .
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BAS E MAP: Thomas Bros. GeoFinder for
Windows, San Diego County, 1995, Page 1147
Carltas Development
Carlsbad Office Campus
5600 Avenida Encinas
Carlsbad, California
PROJECT
SITE
1"=2,000'
SITE
LOCATION
MAP
Project No. IR 040382-001
Date
A~ril2001 Figure No. 1
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040382-001
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING
Our subsurface exploration consisted of excavation of six borings in the vicinity of the proposed building
pads to depths ranging from 20.5 to 30.4 feet below the existing ground surface (bgs). Borings were
excavated utilizing a truck-mounted, Mobile B-61 drill rig equipped with hollow-stem augers. The
purpose of these excavations was to evaluate the physical characteristics of the onsite soils pertinent to
the proposed development. The borings allowed evaluation and measurement of the previously placed
fill soils, evaluation of the soils to be encountered at anticipated foundatiori elevations, identify the
location of formational material with respect to proposed grading operations, and provided representative
samples for laboratory testing. Prior to boring excavation, Underground Service Alelt (USA) was
contacted to coordinate location and identification of nearby underground utilities (USA Ticket
No. 407443).
The exploratory excavations were logged by representatives from our firm. Representative bulk and
undisturbed samples were obtained at frequent intervals for laboratory testing. The approximate
locations of the borings are shown on Figure 2. Subsequent to logging and sampling, the borings were
backfilled.
Laboratory testing was performed on representative samples to evaluate the moisture, density, R-value,
consolidation, hydrocollapse, expansion potential and chemical (corrosion) characteristics of the
subsurface soils. A discussion of the laboratory 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 CONDITIONS
Geology
Based on our subsurface exploration, and review of pertinent geologic literature and maps, the
site is underlain by artificial fill which is underlain by residual soils, Terrace Deposits, and
bedrock material consisting of the Santiago Fonnation. A brief description of the geologic units
as encountered on the site is presented below.
3.l.I Artificial Fill Soils
As encountered during our investigation, artificial fill soils generally consist of dry to
moist, medium dense, silty fine-to coarse-grained sand. An as-graded report of
documenting placement of these soils was not provided for our review at the time of our
report. This material was encountered to depths ranging from 2 to 3 feet below ground
surface (bgs) in Borings 1 through 5 and to a depth of to 5.5 feet bgs in Boring B-6
(Appendix B). These soils were tested to have a very low to medium expansion potential
(Appendix C).
3.1.2 Residual Soils
Relatively minor amounts of what appears to be in-place residual soils were encountered
from a depth of approximately 2 to 5 feet bgs in Boring B-2 at the southwestern portion
of the site. As encountered, residual soils generally consist of dark grayish-green, moist,
very stiff, slightly organic clay. Based on the results of our investigation, and our
experience with similar soils in the project area, this material is anticipated to be
moderately to highly expansive. In general, this material is not suitable for support of
the proposed improvements. We recommend selective grading and stockpmng suitable
material and/or import soils for use as compacted fill.
3.1.3 Terrace Deposits
As encountered during our investigation, Terrace Deposits completely underlies the site
and consists of slightly cemented reddish-brown to light brown and brown to gray-
brown, medium dense to very dense, poorly graded to well-graded silty sand. Occasional
cemented interbeds and hard concretionary layers may be encountered within this unit.
This unit and soils derived from this unit are anticipated to have a very low to medium
expansion potential. This unit was encountered at depths ranging from 2 to 5.5 feet bgs.
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3.1.4 Santiago Formation
Santiago Formation completely underlies the site and constitutes the primary bedrock
unit at the site. As encountered, Santiago Formation generally consists of moderately
cemented, light brown to light grayish-brown and greenish-brown, very' dense, fine to
coarse-grained silty sand with occasional interbeds of well-graded sand. This unit was
encountered at depths ranging from 17 to 21 feet bgs.
Surface and Ground Water
A minor amount of surface water was observed at various locations throughout the site and
appears to have been generated as a result of recent precipitation. However, surface water may
drain as sheet flow in the higher portions ofthe site during rainy periods and accumulate in lower
elevations. Areas of perched water may occur locally on top of the Terrace Deposits adjacent to
existing landscaping andlor after episodes of heavy rainfall. Ground water was observed during
our investigation at depths ranging from 13 to 17 feet below existing site grades. Ground water
levels should be anticipated to fluctuate during periods of high precipitation. In the area of the
proposed parking structure, ground water was encountered at approximate elevations ranging
from 31 to 34 feet ms!. Ground water is not expected to significantly impact the proposed
development provided the recommendations regarding drainage outlined in this report are
implemented. Excavations that encounter the top of the Terrace Deposits may locally encounter
groundwater seepage, especially after site irrigation is implemented.
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4.0 FAULTING AND SEISMICITY
Faulting
Our discussion of faults on the site is prefaced with a discussion of California legislation and
policies concerning the classification and land-use criteria associated with faults. By definition of
the California Mining and Geology Board, an active fault is a fault which has had surface
displacement within Holocene time (about the last 11,000 years). The state geologist has defined a
potentially active fault as any fault considered to have been active during Quaternary time (last
1,600,000 years). This definition is used in delineating Earthquake Fault Zones as mandated by the
Alquist-Priolo Geologic Hazards Zones Act of 1972 and most recently revised in 1997. The intent
of this act is to assure that unwise urban development and certain habitable structures do not occur
across the traces of active faults. The subject site is not included within any Earthquake Fault
Zones as created by the Alquist-Priolo Act.
A review of available geologic literature pertaining to the subject site (Appendix A) indicates that
there are no known active faults crossing the property. The nearest known active regional fault is
the Rose Canyon fault located approximately 4 miles west of the site (Blake, 2000).
Seismicity
The site can be considered to lie within a seismically active region, as can all of Southern
California. Table 1 (below) indicates 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 presently known tectonic framework. Site-specific
seismic parameters included in Table 1 are the distances to the causative faults, earthquake
magnitudes, and expected ground accelerations.
Table 1
Seismic Parameters for Active Faults
Distance
from Fault Peak Horizontal
Potential to Site Slip Rate Maximum Ground Acceleration
Causative Fault (Miles) (mm/yr) Moment Magnitude (g)
Ro~e Canyon 4.0 1.5 6.9 0.54
Newport-
Inglewood 6.3 1.5 6.9 0.43
(Offshore)
Coronado Bank-20.l 3.0 7.4 0.25 Aqua Blanca
As indicated in Table 1, the Rose Canyon Fault is the 'active' fault considered having the most
significant effect at the site from a design standpoint. A maximum moment magnitude earthquake
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040382-001
of moment magnitude 6.9 on the fault could produce an estimated peak horizontal ground
acceleration 0.54g at the site. The Rose Canyon Fault is considered a Type B seismic source
according to Table 16-U of the 1997 Uniform Building Code (lCBO, 1997).
The effect of seismic shaking may be mitigated by adhering to the Uniform BuildiQg Code or
state-of-the-art seismic design parameters of the Structural Engineers Association ofCalifomia.
The soil parameters in accordance with UBC 1997 guidelines are as follows:
Soil Profile Type = Sc (Table 16-J)
Seismic Zone = 4 (Figure 16-2)
Seismic Source Type = R(Table 16-U)
Na = 1.00 (Table 16-S)
Nv= LIS (Table 16-T)
Vertical ground acceleration may be taken as two-thirds of the horizontal grourid acceleration.
Secondary effects associated with severe ground shaking following a relatively large earthquake on
a regional fault that may affect the site include shallow ground rupture, soil liquefaction and
eatthquake-induced settlement. These secondary effects of seismic shaking are discussed in the
foHowing sections.
4.2. I Shallow Ground Rupture
No active faults are mapped crossing the site, and the site is not located within a mapped
Alquist-Priolo Earthquake Fault Zone (Hart, 1997). The nearest mapped segment of the
Rose Canyon Fault extends to within approximately 4 miles west of the site. Cracking
due to shaking from distant seismic events is not considered a significant hazard,
although it is possible at any site.
4.2.2 Liquefaction
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 total loss of shear strength in the affected soil layer. Liquefaction may be
manisfested by sand boils, excessive settlement, and bearing failure.
The onsite materials are not considered liquefiable due to their dense physical
characteristics as indicated by the high blow counts at depth (Appendix B). .
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4.2.3 Earthquake-Induced Settlement
Granular soils tend to density when subjected to shear strains induced by ground shaking
during earthquakes. Simplified methods were proposed by Tokimatsu and Seed (I 987)
and Ishihara and Y oshimine (1991) involving SPT N-values used to estimate earthquake-
induced soil settlement of the . upper 50-foot layer of soil beneath the proposed
development.
Due to the low susceptibility of the site to liquefaction, the potential for earthquake-
induced settlements is considered to be low during strong ground shaking. Earthquake-
induced settlements tend to be most damaging when differential settlements result.
Earthquake-induced total and differential settlements are expected to be negligible.
. 4.2.4 Lateral Spread
Empirical relationships have been derived by Youd and others (Youd, 1993; Barlett and
Youd, 1995; and Youd et aI., 1999) to estimate the magnitude of latenil spread due to
liquefaction. These relationships include parameters such as earthquake magnitude,
distance of the earthquake from the site, slope height and angle, the thickness of
liquefiable soil, and gradation characteristics of the soil.
The susceptibility to earthquake-induced lateral spread is considered to be low for the
site because of their levelness and the low susceptibility to liquefaction.
4.2.5 Tsunamis and Seiches
Based on the distance between the site and large, open bodies of water, barriers between
the site and the open ocean, and the elevation of the site 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 preliminary geotechnical investigation of the site, it is our opinion that the
proposed development is feasible from a geotechnical standpoint, provided the following conclusions and
recommendations are incorporated into the project plans and specifications.
The following is a summary of the geotechnical factors that may affect development of the site.
• Site demolition will include the removal of the existing structure, foundations and underground utilities.
We anticipate disturbance of the near-surface soils.
• Due to the length of time from initial site grading, the lack of documentation and anticipated
disturbance due to future site demolition, the existing fill soils are judged to be unsuitable for support of
the proposed improvements. In addition, residual soils encountered at the southwest corner of the site
are also judged to be unsuitable for support of the improvements. Accordingly, we recommend these
soils to be removed, moisture conditioned, and recompacted (where not removed by the proposed
grading).
• Based on subsurface exploration of the formational materials and surficial soils present on the site,
we anticipate that these materials should be generally rippable with conventional heavy-duty
earthwork equipment. Occasional cemented interbeds and hard concretionary layers may be
encountered within the Terrace Deposits. Oversized materials (that require specialized handling)
may be generated during demolition of the existing structure foundations and underground utilities.
• Residual soils may be moderately to highly expansive and are not recommended for use as compacted
fill within 5 feet of grade in proposed building areas or for use as retaining wall backfill.
Recommendations for selective grading are provided in Section 6.1.5 of this report. The existing onsite
granular soils appear to be suitable material for fill construction provided they are relatively free of
organic material, debris, and rock fragments larger than 8 inches in maximum dimension
• The foundations may be supported by conventional, continuous perimeter, or isolated-spread
footings.
• Transition conditions are anticipated within the office building pads. For preliminary planning
purposes, overexcavation a minimum depth of 4 feet of the cut portion of the Terrace Deposits within
the building pads (extending a minimum horizontal distance of 5 feet beyond the building footprint)
should be anticipated.
• Artificial fill soils and Terrace Deposits were tested to have a very low to medium expansion
potential.
• Laboratory test results indicate the soils present on the site have a negligible potential for sulfate
attack on concrete. The onsite soils are considered to have a low to very high potential for corrosion
to buried uncoated metal conduits.
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040382-001
• Ground water was encountered during our investigation at depths ranging from 13 to 17 feet below
existing site grades. Although not encountered during our investigation, perched water on top of the
Terrace Deposits across the site may occur locally, particularly after period of heavy rainfall or
irrigation. In the area of the proposed parking structure, ground water was encountered at elevations
ranging from 31 to 34 feet ms!. If underground structure foundations are proposed below an
elevation of 3 8 feet msl, some additional excavation may be desired to evaluate potential fluctuations
in ground water levels.
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6.0 RECOMMENDATIONS
Earthwork
We anticipate that earthwork at the site will consist of site preparation, and relatively minor cuts
and fills. We recommend that 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 D of this report. In case of conflict, the following
recommendations shall supersede those in Appendix D of this report.
6.1.1 Site Preparation
Prior to grading, all areas to receive structural fill or engineered structures should be
cleared of surface and subsurface obstructions, including any existing utilities, 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 relative compaction
(based on ASTM Test Method D 1557).
6.1.2 Excavations and Oversize Material
Excavations of the onsite materials may generally be accomplished with conventional
heavy-duty earthwork equipment. However, occasional cemented interbeds and hard
concretionary layers may be encountered within the Terrace Deposits. The approximate
elevation of the top of the Terrace Deposits is shown on Figure 2 may be inferred by
inspection of the Boring Logs in Appendix B.
All excavations should be constructed in accordance with OSHA requirements by a
qualified contractor. For preliminary planning purposes, temporary sloping of 1.5:1 may
be assumed.
We anticipate that scattered amounts of oversize material may be generated during
demolition of the existing structure foundations and underground utilities. Oversize
material should be hauled off site.
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6.1.3 Removal and Recompaction
Existing fill soils are anticipated to be partially disturbed by the site demolition process
and removal of buried foundations and underground utilities. These soils not removed
by the planned grading should be excavated to competent Terrace Deposits across the
site, moisture-conditioned, and then compacted prior to placing any additional fill or
surface improvements. In addition, residual soils (as encountered in the vicinity of
Boring B-2) not removed by the planned grading should be excavated to competent
Terrace Deposits. Because of their clayey nature, we recommend that the existing
residual soils not be used as compacted fill in their present state at finish grade within the
proposed building pad areas or used as retaining wall backfill. These soils should be
thoroughly mixed with granular on site and/or import soils and utilized in parking areas
or as determined by the geotechnical consultant. The thickness of these soils may vary
across the site. In general, however, we anticipate the depth of removals to be on the
order of 2 to +5.5 feet across the site, and may be deeper in localized areas. All removal
bottoms should be reviewed by the geotechnical consultant prior,to fill placement.
6.1.4 Fill Placement and Compaction
The onsite granular soils are generally suitable for use as compacted fill provided they
are free of organic material, debris, and rock fragments larger than 8 inches in maximum
dimension. All fill soils should be brought to near-optimum moisture conditions and
compacted in uniform lifts to at least 90 percent relative compaction based on laboratory
standard ASTM Test Method 01557. For parking areas, we recommend that the upper
12 inches of subgrade soils be compacted to at least 95 percent (based on ASTM Test
Method DI557). The optimum lift thickness required to produce a uniformly compacted
fill will depend on the type and size of compaction equipment used. In general, fill
should be placed in lifts not exceeding 8 inches in thickness. The on site soils typically
possesses a moisture content below optimum and may require moisture conditioning
prior to use as compacted fill.
Placement and compaction of fill should be performed in general accordance with the
current City of Carlsbad grading ordinances, sound construction practice, and the
General Earthwork and Grading Specifications for Rough Grading presented in
Appendix D.
6.1.5 Transition Mitigation
Based on inspection of the boring logs, we anticipate a transition condition to exist
beneath the proposed building footprints. The magnitude of transition may be evaluated
following preparation of the foundation plans and determination of the finish floor
elevations. Based on the anticipated transition conditions, we recommend the proposed
foundations be founded either entirely on properly compacted fill or entirely on
competent Terrace Deposits. For preliminary planning purpose, overexcavation a
minimum depth of 4 feet of the cut portion of the Terrace Deposits within the building
pads (extending a minimum horizontal distance of 5 feet beyond the building footprint)
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6.2
6.3
6.1.6
040382-001
should be anticipated. Similar treatment should be anticipated for foundations situated
across retaining wall backfill.
Expansive Soils and Selective Grading
Residual soils may be moderately to highly expansive and are not recommended for use
as compacted fill at finish grade. These soils were observed in Boring B-2 at the
southwest corner of the site and may be encountered locally throughout the site. We
recommend that expansive soils be placed at depths greater than 5 feet in proposed building
areas and at depths greater than 2 feet in parking areas. Expansive soils are not
recommended for use as retaining wall backfill.
6.1. 7 Import Soils
If import soils are necessary to bring the site up to proposed grade, these soils should be
granular and have an Expansion Index less than 50 per ASTM Test Method D4829.
Please contact this office for further evaluation of the borrow site prior to import.
Surface Drainage and Erosion
Surface drainage should be controlled at all times. The subject structures should have
appropriate drainage systems to collect roof runoff. Positive surface drainage should be provided
to direct surface water away from the structures toward the street or suitable drainage facilities.
Positive drainage may be accomplished by providing a minimum 2 percent gradient from the
structures. Planters should not be designed below grade adjacent to structures unless provisions
for drainage such as catch basins and drains are made. In general, ponding of water should be
avoided adjacent to the structures. Protective measures to mitigate excessive site erosion during
construction should also be implemented in accordance with the latest City of Carlsbad grading
ordinances
Foundation and Slab Considerations
Foundations and slabs should be designed in accordance with structural considerations and the
following recommendations. These recommendations assume that the soils encountered within
5 feet of pad grade have a low to medium potential for expansion. If highly expansive soils are
encountered and selective grading cannot be accomplished, additional foundation design may be
necessary.
6.3.1 Foundations
We anticipate that the proposed structures can be supported by isolated spread and/or
continuous footings. Footings should extend a minimum of 24 inches beneath the
lowest adjacent finish grade. At these depths, footings may be designed for a
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6.3.2
040382-001
maximum allowable bearing pressure of 3,000 psf if founded entirely in properly
compacted fill soils or entirely in competent Terrace Deposits. For footings founded
in compacted fill soils or competent Terrace Deposits, an allowable capacity increase
of 250 psf for every 6 inches of additional width and embedment depth may be used,
not exceeding 4,000 psf. The bearing pressure for site retaining walls along property
lines should be limited to 2,000 psf. The allowable pressures may be increased by
one-third when considering loads of short duration such as wind or seismic forces.
The minimum recommended width of footings is 18 inches for ,-continuous footings
and 24 inches for square or round footings. Footings should be designed in
accordance with the structural engineer's requirements and have a minimum
reinforcement of four No.5 reinforcing bars (two top and two bottom).
We recommend a minimum horizontal setback distance from the face of slopes for all
structural footings and settlement-sensitive structures. This distance is measured
from the outside edge of the footing, horizontally to the slope face (or to the face of a
retaining wall) and should be a minimum of Hl2, where H is the slope height (in feet).
The setback should not be less than 5 feet. Please note that the soils within the
structural setback area possess poor lateral stability, and improvements (such as
retaining walls, sidewalks, fences, pavements, etc.) constructed within this setback
area may be subject to lateral movement and/or differential settlement.
All floor slabs (excluding those subjected to truck or forklift loading) should have a
minimum thickness of 5 inches and be reinforced with No. 4 rebars 18 inches on
center (each way) placed at mid-height in the slab. If heavy vehicle or equipment
loading is proposed for the slabs, greater thickness and increased reinforcing may l?e
required. We emphasize that it is the responsibility of the contractor to ensure that
the slab reinforcement is placed at slab mid-height. Slabs should be designed by the
structural engineer.
In accordance with Appendix 18, Section 1832 of UBC, the slabs-on-grade can be
damp-proofed using a moisture barrier. Slabs should be underlain by a 2-inch layer of
clean sand (sand equivalent. greater than 30), underlain by a lO-mil (or heavier)
moisture barrier (Visqueen), which is in turn is underlain by 2 inches of clean sand.
All penetrations through the moisture barrier and laps should be sealed. All slabs
should be constructed with a reinforced thickened edge. A base coefficient of friction
should not be applied to slab-on-grade where the Visqueen is present.
Our experience indicates that use of additional reinforcement in slabs and foundations
can generally reduce the potential for drying and shrinkage cracking. However, some
cracking should be expected as the concrete cures. Minor cracking is considered
normal; however, it is often aggravated by a high water content, high concrete
temperature at the time of placement, small nominal aggregate size, and rapid
moisture loss due to hot, dry, and/or windy weather conditions during placement and
curing. Cracking due to temperature and moisture fluctuations can also be expected.
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6.3.3
6.3.4
6.3.5
040382-001
The use of low slump/water content concrete can reduce the potential for shrinkage
cracking.
Moisture barriers can retard, but not eliminate, vapor migration from the underlying
soils up through the slab. We recommend that the floor coverings contractor test the
moisture vapor flux rate through the slab prior to attempting the application of
moisture-sensitive floor coverings. "Breathable" floor coverings or special slab
sealants should be considered if vapor flux rates are high. Slip sheets should be
considered if crack-sensitive floor coverings are planned on the slab.
Settlement
The recommended allowable-bearing capacity is based on a maximum total' and
differential settlement of 3/4 inch and 112 inch, respectively. Since settlements are in
part a function of footing size and contact bearing pressures, some differential
settlement can be expected between adjacent columns or walls where a large
differential loading condition exists. However for most cases, differential settlements
are considered unlikely to exceed 112 inch and should generally be less than 114 inch.
With increased footing depth/width ratios, differential settlement should be less.
These values may be increased by one-third for short-term wind or seismic loads.
Design for Expansive Soils
If highly expansive soils are encountered near foundation elevations, potential
damage to building slabs may be minimized by use of slabs with increased reinforcing
and presoaking of subgrade soils.
Lateral Pressures and Shoring Design
Lateral loads may be resisted by assuming a passive pressure of 350 psf per foot of
depth and coefficient of friction of 0.30 between concrete and soil. The lateral
resistance may be taken as the sum of the passive and frictional resistance, provided
the passive resistance does not exceed two-thirds of the total resistance.
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040382-001
For design purposes, the recommended equivalent fluid pressure in each case for
walls founded above the static ground water table (with level backfill) and backfilled
with onsite or import soils of low to medium expansion potential (Expansion Index
less than 60 per ASTM Test Method 4829) is shown on Table 2.
Table 2
Static Equivalent Fluid Weight (pcf)
Condition Level 2:1 Slope
Active 40 60
At-Rest 65 75
Passive 350
(Maximum of 3 ksf)
The above values assume free-draining conditions. If conditions other than these
covered herein are anticipated, the equivalent fluid pressure values should be
provided on an individual case basis by the geotechnical engineer. Construction
traffic, compaction equipment, heavy equipment and vehicular traffic should be kept a
minimum distance of 5 feet or retaining wall height, whichever is greater, from the
retaining wall unless these surcharges are utilized in the design of the retaining walls.
A surcharge load for a restrained or unrestrained wall resulting from automobile
traffic may be assumed to be equivalent to a uniform lateral pressure of 75 psf which
is in addition to the equivalent fluid pressure given above. For other uniform
surcharge loads, a uniform lateral pressure equal to 0.35q should be applied to the
wall (where q is the surcharge pressure in psf). All retaining wall structures should be
provided with appropriate drainage and waterproofing. Wall drainage should be
designed in accordance with the minimum recommendations of Appendix D. This
may require special consideration with regard to providing adequate outlet for the
drainage of the below grade parking structure. Wall backfill should be compacted by
mechanical methods to at least 90 percent relative compaction (based on ASTM Test
Method D 1557) and at least 2 percent over the optimum moisture content.
Wall footing design and setbacks should be performed in accordance with the
previous foundation design recommendations and reinforced in accordance with
structural considerations. Soil resistance developed against lateral structural
movement can be obtained from the passive pressure value provided above. If wall
rotation (MH) is smaller than 0.04, a factor of safety of 2.5 should be used for the
passive resistance. The upper 1 foot of passive resistance should be neglected unless
the soil is confined by pavement or slab.
Due to space limitations, temporary shoring of vertical excavations adjacent to the
side of the parking structure may be required. We recommend that shored vertical
excavations be retained either by a cantilever shoring system deriving passive support
from drilled solider piles (lagging-shoring system) or a restrained tie-back and pile
system. Based on our experience, if lateral movement of the shoring system on the
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6.4
6.5
040382-001
order of 1 to 2 inches cannot be tolerated or for walls higher than 20 feet, we
recommend the utilization of a restrained tie-back and pile system.
We recommend the following provisional geotechnical parameters for shoring design.
For design of cantilevered shoring, a triangular pressure distribution resulting from an
equivalent fluid pressure as described in Table 2. Lateral earth pressures for design
of restrained shoring may be taken as a rectangular pressure of 20H (pst) were H is
the height (feet) of the excavation, including slopes above. For preliminary design of
tie-backs, we recommend a concrete-soil bond stress based on an internal angle of
friction of 28 degrees and the methods to be used by the contractor. The design value
should be evaluated by field tests. Anchors should be grouted only behind the 40-
degree line up from the footing base. This portion should also be used for calculating
resisting forces. Permanent tie-back anchors should be individually proof-tested to
ISO percent of design capacity. Further details and design criteria for tie-backs can be
provided as appropriate. Since design of retaining systems is sensitiye to surcharge
pressures behind the excavation, we recommend that this office be consulted if
unusual load conditions are anticipated.
Geochemical Considerations
Concrete in direct contact with soil or water that contains a high concentration of soluble sulfates
can be subject to chemical deterioration commonly known as "sulfate attack." Soluble sulfate
results (Appendix C) indicated a soluble sulfate contents ranging from 0.018 to 0.020 percent.
According to Uniform Building Code Table 19-A-4, these concentrations represent a negligible
potential for sulfate attack. Table 19-A-4 provides minimum mix design requirements for
concrete.
Minimum resistivity and pH tests were performed on representative samples of subgrade soils
(Appendix C). Based on our results, the site soils have a very high corrosion potential to buried
uncoated metal conduits (City of San Diego, 1992). Test results also indicate chloride contents
ranging from 170 to 350 parts per million (ppm). The test results should be provided to the
appropriate design engineers.
Preliminary Pavement Design
For preliminary design purposes, we have utilized a design R-value of 21 for the subgrade soils
based on our experience, laboratory test results and knowledge of soils in the project area. It is
recommended that representative samples of actual subgrade materials be obtained after grading
and tested to provide the final pavement design. The project architect should. review the
provided traffic index indices prior to final design.
Utilizing the design procedures outlined in the current CaItrans Highway Design Manual and a
design R-value of21, preliminary pavement design sections are provided in Table 3.
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6.6
040382-001
Table 3
Preliminary Pavement Design Sections, R-value = 21
Pavement Loading Traffic Index
Condition (20-Year Life) Anticipated Pavement Sections
Parking Areas 4.5 3.0 inches AC over
6.0 inches Class 2 Base
Drive Areas 5.0 4.0 inches AC over
5.0 inches Class 2 Bas~
Truck Drive Areas 6.0 5.0 inches AC over
7.0 inches Class 2 Base
For areas subject to unusually heavy truck loading (Le., trash trucks, delivery trucks, etc.)~ we
recommend a full depth of Portland Cement Concrete (P.C.C.) section of 7 inches with
appropriate steel reinforcement and crack-control joints as designed by the project structural or
civil engineer. We recommend that sections be as nearly square as possible. A 3,500 psi mix
that provides a 600 psi modulus of rupture should be utilized. The actual p'avement design
should also be in accordance with City of Carlsbad and ACI criteria. All pavement section
materials should conform to and be placed in accordance with the latest revision of the California
Department of Transportation Standard Specifications (Caltrans) and American Concrete
Institute (ACI) codes and guidelines.
Prior to placing the Asphalt Concrete (AC) or PCC pavement section, 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 to 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 to the aggregate base. Concrete swales should be designed in roadway or
parking areas subject to concentrated surface runoff.
Construction Observation and Plan Review
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. Construction observation of all
onsite excavations and field density testing of all compacted fill should be performed by a
representative of this office so that construction is in accordance with the recommendations of
this report. Final project drawings should be checked by Leighton and Associates, Inc. before
grading to see that the recommendations provided in this and previous reports are incorporated in
project plans.
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040382-001
7.0 LIMITATIONS
The conclusions and recommendations in this report are based in part upon data that were obtained from
a limited number of observations, site visits, excavations, samples, and tests. Such information is by
necessity incomplete. The nature of many sites is such that differing geotechnical or geological
conditions 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 and Associates, Inc. has the
opportunity to observe the subsurface conditions during grading and construction of the project, in order
to confirm that our preliminary findings are representative for the site.
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8-S
Qt at 2'
8-6 Qtat S.S' Tsa at 20'
GWat17' TD=21.S'
Tsa at 21'
GWat 14.S' TD=21.S'
8-4
Qt at 2' Tsa at 20' GWat 16'
TD=21.S'
\.,
25' setback
.. S ~ . Encl.na. . .~. r-. J .' ; ,~ Avenlda . . ;.'H _l'"" ..
, :.;z;~ .,~L.
~ P!!.~se_~:-+"-E~~_se II: .. ~
75,000 sf.
3 story
building
250'
. 78,000 sf.
3 story
building
[ .
LEGEND
~
8-6 0 Approximate locatton of
geotechnical boring
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(;)
NO RTH
BORING LOCATION MAP
Carltas Development
Carlsbad Office Campus
5600 Avenida Encinas
Carlsbad. California
Project No.
Sc~le
Engr./Geol.
Drafted By
Date
040382-001
Not to scale
TJUAXT
KAM
ADril2001
Leighton and Associates, Inc.
II
Figure No.2
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040382-001
APPENDIX A
REFERENCES
Blake, 2000, EQFAULT, Version 3.0
Bartlett, S.F. and Youd, T.L., 1995, Empirical Prediction of Liquefaction-Induced Lateral Spread,
Journal of Geotechnical Engineering, Vol. 121, No.4, Apri11995.
California, State of, Department of Transportation, 1998a, Standard Specifications, dated January, 1988.
----, 1988b, Highway Design Manual, dated August 5, 1988.
Hart, 1997, Fault-Rupture Hazard Zones in California, Alquist-Priolo Special Study Zones Act of 1972
with Index to Special Study Zones Maps: Department of Conservation, Division, Division of
Mines and Geology, Special Publication 42.
International Conference of Building Officials, 1997, Uniform Building Code.
Ishihara, K., and Yoshimine, M., 1991, Evaluation of Settlements in Sand Deposits Following
Liquefaction during Earthquakes, Soils and Foundations, Vol. 32, No.1, pp: 173-188.
Leighton and Associates, Inc., 1992, Geotechnical Hazards Analysis and Mapping Study, Carlsbad,
California, November 1992, 84p.
Tan, S.S. and Kennedy, M.P., 1996, Geologic Maps of the Northwestern Part of San Diego County,
California, California Division of Mines and Geology Open-File Report 96-02, Plate 1 of 2,
Scale 1 :24,000.
San Diego, City of, 1992, Program Guidelines for Design Consultants, Corrosion Control Guidelines,
February, pages 9-26.
Smith Consulting Architects, 2001, Schematic Site Plan (Option One), Carlsbad Office Campus,
Carlsbad, California, Job No. 00291, dated January 22, 2001.
Tokimatsu, K., and Seed, H. B., 1987, Evaluation of Settlements in Sands Due to Earthquake Shaking,
ASCE Journal of Geotechnical Engineering, Vol. 113, No.8, dated August 1987.
Youd, T.L., 1993, Liquefaction-Induced Lateral Spread Displacement, NCEL Tech. Note 1862, Naval
Civil Engineering Laboratory, Port Hueneme, California
Youd, T.L., Hanson C.M., and Barlett, S.F., 1999, Revised MLR Equations for Predicting Lateral Spread
Displacement, Proceedings of the 7th U.S.-Japan Workshop on Earthquake Resistant Design of
Lifeline Facilities and Countermeasures Against Soil Liquefaction, November 19, 1999, pp. 99-
114.
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I, GEOTECHNICAL BORING LOG KEY
Sheet of Date __________ _
P.ect KEY TO BORING LOG GRAPIDCS
_._1_ _1_
Project No.
DIlling Co.
Hole Diameter
Top of Hole
• 0 .r:."" .-+-+-.r:.m 11. OJ 11.0 OJ OJ 1Il-.J 00 ~'-" t... (.!)
III OJ +-0 Z
+/-ft.
.
0 +-Z III 0
OJ 3 0
ou.. -11. -t...
E ttl OJ
III 0-CI>
Type of Rig
Drive Weight Drop
Ref. or Datum
j) "" .r."" +-OJ~ GEOTECHNICAL DESCRIPTION .-III •
Ill"" t...'-" 1Il~ C'f-~+--u OJO 'tic u. 011. ._ OJ _CI> '-" o+-LOgged By j) E C '-::i t... 0 g'-" Sampled By 0 u
in.
0 ~ CL Inorganic clay of low to medium plasticity; gravelly clay; sandy clay; silty clay; lean
clay
I ~ CH Inorganic clay or high plasticity; fat clay
r~~<~~,.: OL-OH Organic clay, silt or silty clay-clayey silt mixtures
I SPT ML T. silt; veIY fine sand; silty or clayey fine sand' clayey silt with low' P-'~lLJ SAMPI .E I MH Inorganic silt; diatomaceous fine sandy or silty soils; elastic silt 5 ~ S~Pl ~E CL-ML Low plasticity clay to silt mixture I I ML-SM Sandy silt to silty sand mixture
~ P.% CL-SC Sandy clay to clayey sand mixture
I ~ I' SC-SM Clayey sand to silty sand mixture '. SW . '. Well graded sand' gravelly sand little or no fines 10
'1\ .' SP Poorly graded sand; gravelly sand, little or no fines
1 SM . Silty sand; poorly graded sand-silt mixture
0.0. SC Clayey sand; poorly graded sand; clay mixture I, [)'~o'---?, GW Well graded gravel i°'r-'6 mixture little or no fines
~ .0 'Y'C Gr~ ND fA ~: ¥ GP Poorly graded gravel; gravel-sand mixture, little or no fines
I 15 J~ 1 ~RTT~ I 0: ,.' ~~. :..rr. GM Silty gravel: .i1t mixture
~ GC Clayey gravel mixture
I ,~
Sandstone ~.
Siltstone i---:-_
roo.
I 20 ---
o.
0,... o· Breccia (angular g~vel and cobbles or ,WllI ' rnnulnm"rote)
~ ..7lO\.
ned) ~ r. lte (rounded gravel and cobble
I ' \ ' Igneous granitic or granitic type rock 1-J
~\: <,
Metavolcanic or rock
II /II~ III Artificial or man-made fill
251M . Asphaltic concrete
I XXXX Portland cement concrete
-
110 -
15A(11/77) LEIGHTON & ASSOCIATES
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~-!~ing Co.
~i ~ Diameter
:'Ilation Top of Hole
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8 in
+1-50
3
4
5
6
GEOTECHNICAL BORING LOG B-1
Sheet ~ of _2 __ _
CarItas/Carisbad Office Campus Project No. 040382-001
•
F&C Drilling Type of Rig B-61
Drive Weight
ft. Ref. or Datum
________ ~1..:..40!:..J'P""o~un~d~s~ ________ Drop -.ML in.
55
95
5014"
SM-SC
105.0 20.4 SW
SW
SM
120.2 12.4 SM
Mean Sea Level
GEOTECHNICAL DESCRIPfION
@ 5': Silty fine to medium SAND: red-brown to brown, moist, medium dense;
slightly. cemented; slightly clayey
@ 10': Silty fine to medium SAND: dark brown, moist, medium dense; slightly
clayey
@ 13': Ground water encountered
@ 15': Well-graded fine to coarse SAND: brown, wet, medium dense; 2-112"
rounded gravel in shoe
SANT~G6FORMATION------------------------
@ 20': Silty fine to coarse SAND: grayish-brown, moist to wet, medium dense
@ 25': Silty fine to coarse SANDSTONE: grayish-brown, moist, very dense;
moderately cemented
LEIGHTON & ASSOCIATES
I GEOTECHNICAL BORING LOG B-1
)ate ____ --=:3'--7'--~01~ __ _ Sheet 2
Project No.
Type of Rig
of 2
040382-001
B-61
'rlet Carltas/Carlsbad Office Campus
hng Co. F&C Drilling
[ole Diameter 8 in Drive Weight ........ .... . ~14.0~p~.o~u_n •• d_.s, ... Drop 30 in. --
:1 tion Top of Hole +1-50 ft. Ref. or Datum Mean Sea Level
... :J'I ""' ui'" C . +-Ol~ 0 +-GEOTECHNICAL DESCRIPTION fa 0 Z 1Il 0 .-,-"'" 1Il •
.J::.""' .-1Il 1Il'" :l+-1Il~ +-+-.J::.Cl Ol Ol 3 0 C4--u o.Ol 0.0 +--0lL. OlO +-c u. OlOl Ill...! 0 0. -'-00. .~ Ol en ~"'" 04-'-Z COOl "'" o+--AXT '-' (!) E :J'I .-~ Logged By
III a.. E C
l en '-0 g'-' 0 t.) Sampled By AXT
30 ,I ,1','1· 7 "OIA" .. <:M @ 30': Same as previous
I -Total Depth = 30.4 Feet
-
Ground water encountered at 13 feet
Backfilled with cuttings, bentonite, and concrete on 317/01
Capped with 2 to 3 inches asphalt concrete
-, -
35-
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-
-I -
10 40-
I -
-
J -
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I 45-
-
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-150
-, -
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-
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-
1 -
-
.J/hl) -
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iliing Co.
Hole Diameter ~Iation Top of Hole
!~
iC II 0 .r:.'" .-++ .r:.m o..QI 0..0 QIQI III...J
QI'V 00 c... (!) --,
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0 ~~ -I ~ -
45 -, -
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III
(I)
Bag-2
@0'-5'
1
2
3
4
5
6
GEOTECHNICAL BORING LOG B-2
Sheet ~ of _1_
Carltas/Carlsbad Office Campus Project No. 040382-001
F &C Drilling Type of Rig B-61
Drive Weight ~1~40~p~,vo,u~ .. n~d.s~ Drop 30 in --
ft. Ref. or Datum Mean Sea Level
J'I ""' 01""' + QI~ GEOTECHNICAL DESCRIPTION +
(/10 .-c...'V (/I •
(/I", ;j+ III~
3 0 C<f-u~ oll.. QlO +c
00.. (/IQI -c... _(I) IOQI 'V ._+ Logged By AXT J'I °c '-::i 0.. EO c... g'V Sampled By AXT 0 u
@0-4': Asphalt Concrete
----'~_4~-~":..~g~r~g!t~B~s~.:.. _______________ ~ ________ --
SM ARTIFICIAL FILL
----,@ 8": Silty fine to coarse SAND: gray-brown, dry, medium dense; possibly
, ___ ~e~0!!1l!.0~e<!.gE1!!itE _________________________ /
28 112.4 13.0 CH RESIDUAL SOIL
@3.5': CLAY: dark grayish-green, moist, very stiff; slightly organic
28 SM-SC-TERAACEDEPOOITS--------------------------
@ 5': Silty fine to medium SAND: reddish-brown to gray-brown, moist, medium
dense; slightly clayey
39 97.7 8.6 SP @ 10': Poorly-graded fine SAND: brown, moist, medium dense; slightly silty
¥
44 SP @ 15': Same as previous; dense
------------------------------------------SM-SC SANTIAGO FORMATION
77 @20': Silty fine SAND: reddish-brown to grayish-green, very dense; slightly
oxidized; slightly clayey
64/6" SW @25': Well-graded medium to coarse SAND: light brown, moist, very dense,
\ moderately cemented
Total Depth = 25.~ Feet
Ground water encountered at 14 feet at time of drilling.
Backfilled with soil cuttings on 317/01
Capped with 2 to 3 inches asphalt concrete
LEIGHTON & ASSOCIATES
I GEOTECHNICAL BORING LOG B-3
r ct __________________ ~C~a=r~It~a=s~/C==ar=l=sb~a=d~O~f~fi~c~e~C~a=m=Pcu=s~ ______________ _
Sheet _1_ of _1_
Project No ..
Type of Rig
040382-001
B-61
II 3-7-01
)n mg Co. F&C Drilling
'~~Diameter 8 in Drive Weight 140 ~ounds Drop R in.
.I~ ,tion Top of Hole +/-47 ft. Ref. or Datum Mean Sea Level
-4 I . ::n "'" iii"'" I 0 + + OJ~ GEOTECHNICAL DESCRIPTION 0 z 1/10 .-c..V' 1/1 •
.J::."'" .-1/1 :3 0 1/1"'" :::1+ 1Il~ ++ .J::.ID OJ OJ C'+--u 0. OJ 0.0 + -olL. OJo tic u .
>'+-OJ OJ 1Il-.J 0 0. iCc.. 00. ._ OJ (f)
00 '-z V' 0+ -~'-' E OJ '-::5 Logged By AXT
(!) III 0.. ::n E C
1 (f) c.. 0 ~'-' AXT a u Sampled By
0 Bag-3 @ 0-3.5": Asphalt Concrete
I-":-" @0'-5' ----'@iJ:.s~-7-:0,:::_~g[fe~~e_B~s<:.. ___________________ ----r
J -.~.~ SM ARTIFICIAL FILL
-----,@ 7": Silty fine SAND: brown, moist TERMCEDEPOOITS--------------------------
-.... ~ 1 37 116.5 14.9 SM-SC @2.5': Silty clayey SAND: gray-brown to red-brown and white, moist, medium
I dense; calcium carbonate blebs visible
-: :-:~
5--:~:. (.Z 2 22 SM @5': Silty fine SAND: grayish-brown, moist, medium dense · . I -· ..
-:
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-. · .
· .. · . 10--
1 3 78 120.9 15.0 @ 10': Same as previous; dense
· . -. -· .
35 -' ..
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-' .. ~
· .
I 15-· . @ IS': Silty fine to medium SAND: reddish-brown to gray', moist to wet, very , " 4 77
00 dense; 1/4" to 1/2" subangular gravels common
-000
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3 -o 0
000
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00' -~ • 0
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o 0 -00'
1 :~: • 0
20-0":' - ---SANT~G6FORMATION----------------~--------
00 5 73 SM
-o • @20': Silty fine to SAND: brown to greenish-brown, moist, very dense; few fine
000 gravels; moderately cemented
I· -Total Depth = 21.5 Feet
-Ground water encountered at 14 feet at time of drilling
Backfilled with soil cuttings on 317101
Capped with 2 to 3 inches asphalt concrete
-I 25-
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21.
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LEIGHTON & ASSOCIATES
I GEOTECHNICAL BORING LOG B-4
I 3-7-01
'ect CarItas/Carlsbad Office Campus 'linge --0-. --------===:....:::..:::::..::F::.::&=C:..-n;:;.:..:ri.:..:n:.::in:..-g=:=£=---------
HI 8' D' W'h 140
Sheet _1_-of _1_
project No. 040382-001
Type of Rig B-61
D 30 e DIameter In rIve eIg t poun s rop m.
~ ~ation Top of Hole
--
+1-47 ft. Ref. or Datum Mean Sea Level
. ::11 '"' iii'"' c 0 .... .... QI~ GEOTECHNICAL DESCRIPTION I 0 Z til 0 .-c...'-" til •
.I:.'"' .-til til'"' III~ ........ .I:. 0) QI QI 3 0 C'+-=' .... u~ a.QI 0.0 .... -OIL QlO .... c
QIQI 111.....1 0 a. -c... 00. .~ QI -(I) QI~ o~ c... Z a:JQI '-" o-+-Logged By AXT C,!) E ::11 1::c '0::5 ~ III a.. '-0 (I) 0 u (1)'-" Sampled By AXT
0 Bag-4 @ 0-3": Asphalt Concrete ~. f:1 @0'-5' -su--\.@_3':-~":... ~g.8r~g~tc:...B~s~ _________________________ r
15
-::·:iZ ARTIFICIAL FILL
-:~:~ -SM--,@ 6': Silty fine SAND: light brown, moist TERRACE-DEPOSITS - - - - - - - - - - - - - - - - - - - - - - - - - -
d
-
;1 -· .
· .
5-. ~.:.:. · .t/;. 1 47 116.8 15.9 SM-SC @5': Silty clayey fine SAND: red-brown to gray-brown, moist, medium dense;
'6 -:J2~ calcium carbonate blebs visible
:.)0--:;:;~ J -
· :.~ -.. .'~
10-
::.:~
I' :~:;~ 2 31 SM-SC @ 10': Silty fine SAND: gray-brown, moist, medium dense; slightly clayey
-::.:~
35 -:~.;~ t -.~ .... ~ -.. ,~
Ii 15-:~. :'.f%
3 58 107.8 20.~ SP @ 15': Poorly-graded fine to medium SAND:' grayish brown, moist to wet, :::".-. .. medium dense; thin beds of medium to coarse SAND; slightly micaceous;
-:":-::":-:: slightly silty · . . '
j -:.: <:-: .:: · . · . . ' . -' .. . .
-:.'.::-:.:: · .
I · .
20-:.-~.<~.~< tr 70/6"
-----------------------------------------
4 SP SANTIAGO FORMATION If \@ 20': Silty fine SAND: light grayish brown, moist, vel)' dense; moderately -cemented
I -Total Depth = 20.5 Feet
Ground water encountered at 16 feet at time of drilling
-Backfilled with soil cuttings on 3/7/0 I
Capped with 2 to 3 inches asphalt concrete
-I 25-
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I -
-
I -
"10
J5A( 11/77) LEIGHTON & ASSOCIATES
1:
I GEOTECHNICAL BORING LOG B-3
·t CarItas/CarIsbad Office Campus I 3-7-01
n Ingc--o-.--------------~~~~==F=&~C~D~r~i~II=in~g~~~---------------
Sheet _1_ of
Project No.
Type of Rig
1
040382-001
o Diameter
I : ion Top of Hole
,
45 5
4Q 10 I
· . .. . · . · ..
· . · .. · . · ..
.. . · .. · . · ..
· . · ..
.. .....
· .. . .....
· .. .. :.".
8 in
+1-50
2
3
Drive Weight
ft. Ref. or Datum
J) ""' +-+-OJ~
\Ilo \Il,,", ,-v
3° C'+-::1+-aLL OJU tic
iii'-on. .-QJ v o+-OJ J) 0-E C '-a
0 u
B-61
________________ ---=-1..:.40~p:.::;o=u:.:.nd:::s"__ ____________ ---Drop .l.Q... in.
to""' \Il • ttI~ -u u.
_C/) .-:::i g'-'
Mean Sea Level
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
AXT
AXT
@ 0-3.5": Asphalt Concrete
- - - -'@ 3.5"-7.5": Aggregate Base . r SP ARTIFICiAL-FILL - - - - - - - - - - - - - - - - - - - - - - - - - - - -
29 106.2 5.5
32
____ ,@ 8.5": Silty fine SAND: brown, moist
SP TERRACEDEPOsiTS - - -:-- - - - - - - - - - - - - - - - - - - - - -
SP
@ 5': Poorly-graded fine SAND: red-brown to brown, moist, medium dense;
slightly silty
@ lO': Poorly-graded fine SAND; gray to orange, moist, dense; slightly oxidized
80/10" 112.2 17.4 SW @ 15': Well-graded fine to coarse SAND: light brown, wet, very dense
4 97
f-L--'---4 __ -+_-IfLl---t--+---t--....,M"-!-=:L---h -SANTIAGO FORMA:fi:ON-- - - - - - - - - - - - - - - - - -.-- - - - -
@ 21': SILTSTONE: grayish brown, dry to slightly moist, very stiff
Total Depth = 21.5 Feet
Ground water encountered at 14.5 feet at time of drilling
Backfilled with soil cuttings on 3/7/01
Capped with 2 to 3 inches asphalt concrete
LEIGHTON & ASSOCIATES
I
Jeel 3-7-01
'ing Co.
!:1i e Diameter ::t ~ation Top of Hole
I !IC
, t~ ~O)
QI QI ~.5
I QI~ CJ~ L I 0 ~
0_
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-::-: ..
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: .:~.:.~. -:'--::-'.::
' ..
-:':'::-:-:: .. : ....
'.' .. -:':'::-:':: .. " ". i 10-=<
-:.:. ::':-::
I, -~->-:.:: .: ....
" . -:':'::-:-:-.. ".
1 15-:.:.::.:'::
, : '". -:':'::':-:
' .. . ..... -::::-J ..... . -~.:.>:.:: ..
-:.:.::.::::
I " 20'-'" ,--;--: ;-.:;-:
-
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-
-
'25-
-
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-
-
III QI +-0 Z
8 in
+/-50
.
0 Z
QI -Q. e III (I)
2
3
4
5
GEOTECHNICAL BORING LOG B-6
Sheet _1_-of _1_
Caritas/Carlsbad Office Campus Project No.
Type of Rig
040382-001
B-61 F&C Drilling
Drive Weight
ft. Ref. or Datum
________ ~1:...!4..!!.0J:p~o~u:!!n!!:ds~ _______ Drop .1!!... in.
Mean Sea Level
+-
111 0
:3 0
oLl..
-L a:lQ,l a..
40
27
80
70/10"
:Jl ,......
+-Qlx .-
Ill".... LV
C'+-:::1+-
QlO "tic OQ. .-QI v o+-:Jl I:C L 0
0 U
12004 12.8
1l0.7 2004
104.6 20.2
ui""'" III • III~
u~
-(I) --:::5 gv
GEOTECHNICAL DESCRIPTION
Logged By
Sampled By
AXT
AXT
@ 0-2.5": Asphalt Concrete
- - - -'@ 2.5"-6.5": Aggregate Base . r SM ~------------------------------------
SP
SP
SP
SW
ARTIFICIAL FILL
@ 6.5": Silty fine SAND: Mottled dark brown to brown, moist, medium dense
TERMCEDEPOOITS---------------------------
@ 5.5': Contact with Terrace Deposits
@ 6': Poorly-graded fine SAND: reddish-brown, moist, medium dense
@ 10': Same as previous
@ 15': Poorly-graded fine to medium SAND: brown, wet, dense; slightly silty
-------------------------------------SANTIAGO FORMATION
@ 20': Well-graded fine to coarse SAND: light brown, wet, very dense
Total Depth = 21.5 Feet _
Ground water encountered at 17 feet at time of drilling.
Backfilled with soil cuttings on 317701
Capped with 2 to 3 inches asphalt concrete
LEIGHTON & ASSOCIATES
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040382-001
APPENDIXC
Laboratory Testing Procedures and Test Results
Chloride Content: Chloride content was tested in accordance with DOT Test Method No. 422. The
results are presented below:
Sample Location Chloride Content, ppm Chloride Attack Potential*
B-1, 0-5 Feet 170 Threshold
B-3, 0-5 Feet 350 Positive
*per City of San Diego Program Guidelines for Design Consultant, 1992 .
Consolidation Tests: Consolidation tests were performed on selected, relatively undisturbed ring samples in
accordance with Modified ASTM Test Method 02435. Samples were placed in a consolidometer and loads
were applied in geometric progression. The percent consolidation for each load cycle was recorded as the
ratio of the amount of vertical compression to the original I-inch height. The consolidation pressure curves
are presented on the attached figure.
Direct Shear Tests: Direct shear tests were performed on selected remolded and/or undisturbed samples
which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during
testing. After transfer of the sample to the shear box and reloading of the sample, the pore pressures set up
in the sample (due to the transfer) were allowed to dissipate for a period of approximately 1 hour prior to
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 than 0.001 to 0.5 inches per minute
(depending upon the soil type). After a "peak" value of shear strength was observed or after a shear strength
was observed or after a shear strain of 0.2 inches if no peak was observed, the motor was stopped and the
sample was allowed to "relax" for approximately 15 minutes. The stress drop during the relaxation period
was recorded. It is anticipated that, in a majority of samples tested, the 15 minutes relaxing of the samples
is sufficient to allow dissipation of pore pressures that may have set up in the samples due to shearing. The
drained peak strength was estimated by deducting the shear force reduction during the relaxation period
from the peak shear values. The shear values at the end of shearing are "ultimate" values. The drained peak
strengths are presented in the test data.
Friction Angle Apparent
Sample Location Sample Description Test Type (degrees) Cohesion (pst)
B-2, 11 Feet Brown poorly-graded fine sand Undisturbed 33 140
B-4, 6 Feet Red-brown to gray-brown silty Undisturbed 30 1020 clayey sand
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040382-001
APPENDIX C (continued)
Hydrocollapse: Selected samples were loaded in a consolidometer to the proposed overburden pressure.
The samples were then inundated with water and the percent hydrocollapse was measured and recorded
below.
Sample Location % Hydrocollapse
B-6, 6 Feet 0.2@ 700 psf
Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion Index
Test, U.B.c. Standard No. 18-2. Specimens are molded under a given compactive energy to approximately
the optimum moisture content and approximately 50 percent saturation or approximately 90 percent relative
compaction. The prepared I-inch thick by 4-inch diameter spedmens are loaded to an equivalent 144 psf
surcharge and are inundated with tap water until volumetric equilibrium is reached. The, results of these
tests are presented in the table below:
Compacted Dry Expansion Expansion
Sample Location Sample Description Density (pcf) Index Potential
B-1, 0-5 Feet Brown silty sand 120.8 2 Very Low
B-3, 0-5 Feet Gray brown silty clayey 114.4 56 'Medium sand
Moisture and Density Determination Tests: Moisture content and dry density determinations were
performed on relatively undisturbed samples obtained from the test borings. The result~ of these tests are
presented in the boring logs. Where applicable, only moisture content was determined from "undisturbed"
or disturbed samples.
Minimum Resistivity and pH Tests: Minimum resistivity and pH tests were performed in general
accordance with California Test Method 643. The results are presented in the table below:
Sample
Sample Location Description pH Minimum Resistivity (ohms-em)
B-1, 0-5 Feet Brown silty sand 7.2 4600
B-3, 0-5 Feet Gray brown silty clayey 8.0 890 sand
C-2
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040382-001
APPENDIX C (continued)
Soluble Sulfates: The soluble sulfate contents of selected samples were determined by standard
geochemical methods. The test results are presented in the table below:
Sample Location Sulfate Content (%) Potential Degree of Sulfate Attack*
B-1, 0-5 Feet 0.018 Negligible
B-3, 0-5 Feet 0.020 Negligible
* Based on the 1997 edition of the Uniform Building Code, Table No . .19-A-4, prepared by the
International Conference of Building Officials (ICBO, 1997).
"R"-Value: The resistance "R"-value was determined by the California Materials Method No. 301 for base,
subbase, and basement soils. The samples were prepared and exudation pressure and "R"-value determined.
The graphically determined "R"-value at exudation pressure of300 psi is reported.
Location Design R-Value
B-3, 0-5 Feet 21
C-3
I ...
rERATEST LABS" INC '1'--:::::~~'--' ~-::~~TAS I OFF~~NSOLIDATION
Project Number: 040382-001 I' Boring Number: B-2
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4.00
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6.00
7.00
8.00
9.00
10.00
Sample Number: 3
STRESS (ksf)
1.0
Date: Q3[19/01
Tested By: BCC
Depth: 11.0-11.5
10.0 100.0
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Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Pagelof6
LEIGHTON AND ASSOCIATES, INC.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING
1.0 General
3030,1094
1.1 Intent: These General Earthwork and Grading Specifications are for the grading and
earthwork shown on the approved grading planes) 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 geotechnicalreport(s).
1.2 The Geotechnical Consultant of Record: Prior to commencement of 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 commencement of 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 inform
the owner, recommend appropriate changes in design to accommodate the observed
conditions, and notify the review agency where required. Subsurface areas to be
geotechnicallyobserved, 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 perform relative compaction testing of fill to determine 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.
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Leighton and Associates,Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 2 of6
1.3 The Earthwork Contractor: The Earthwork Contractor (Contractor) shall be qualifiec\,
experienced, and knowledgeable in earthwork logistics, preparation and processing of
ground to receive fill, moisture-conditioning and 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
commencement of 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, unsatisfactory conditions, such as unsuitable soil, improper moisture condition,
inadequate compaction, insufficient buttress key size, adverse weather, etc., are resulting 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
3030.1094
2.1 Clearing and Grubbing: Vegetation, such as brush, grass, roots, and other deleterious
material shall be sufficiently removed and properly disposed of in a method acceptable to
the owner, governing agencies, and the Geotechnical Consultant.
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 handling ofthese materials prior to continuing to work in that area.
As presently defined 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.
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Leighton and Associates/Inc.
GENERAL EARTHWORK AND GRADING SPECIFICA nONS
Page 3 of6
2.2 Processing: Existing ground 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 shall 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 by the 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 shaH 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 subgtade
for the fill.
2.5 Evaluation! Acceptance of Fill Areas: All areas to receive fill, including removal and
processed areas, key bottoms, and benches, shaH be observed, mapped, elevations
recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable
to receive fill. The Contractor shaH obtain a written acceptance from the Geotechnical
Consultant prior to fill placement. A licensed surveyor shall provide the survey control for
determining elevations of processed areas, keys, and benches.
3.0 Fill Material
3030.1094
3. I General: Material to be used as fill shall be essentiaHy free of. organic matter and other
deleterious substances evaluated and accepted by the Geotechnical Consultant prior to
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.
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Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 4 of6
3.3 Import: If importing offill 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 Consu Itant 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
3030.1094
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
DI557-91).
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 DI557-91). 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 uniformity.
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 D 1557-91.
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 filllbedrock benches).
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Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
PageS of6
4.6 Frequency of Compaction Testing: Tests shall be taken at intervals not exceeding 2 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 Geotechnical Consultant shall documentthe 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
3030.1094
Excavations, as well as over-excavation for remedial purposes, shall be evaluated by the
Geotechnical Consultant 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 materials for construction of the fill portion of the
slope, unless otherwise recommended by the Geotechnical Consultant.
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Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 6 of6
7.0 Trench Backfills
3030.1094
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
conduitto 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 every 300 feet of trench and 2 feet offill.
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.
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PROJECTED PLANE
1 TO 1 MAXJMlJM FROM TOE
OF SlOPE TO GAOUNO
,-------
CUT fACE
NATURAL
GROUND
'\--
2' MIN.
KEY DEPTH
SHALL BE CONSTRUCTED PRIOR
TO Fl.L PlACEMENT TO ASSURE
ADEQUATE GEOlOGIC CONOmONS
2' MIN.
KEYDEPTH
KEYING AND BENCHING
BENCH HEIGHT
HEIGHT
FILL SLOPE
FILL-OVER-CUT
SLOPE
CUT -OVER-FILL
SLOPE
For Subdrains See,
Standard Detail C
I3ENCHI«J 8I-W.L BE DONE WHEN SlOPES
ANGLE IS EQlW. TO OR GREATER THAN 5:1
MIUJM BENCH HEIGHT SHAll BE <4 FEET
t.INMUM FI..L WIDTH SHALL BE g FEET
GENERAL EARTHWORK AND GRADING [][TI
SPEClFlCA1l0NS ' u
STANDARD DETAILS A
REV. 4'11$6
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FINISH GRADE
---------------------------------------------------------------------------
-::-: --:-=;O·-MIN.:::---:COMPACTeDFIU.:::~-:-:: -------------------------------------------~-------------------------------------------------------------------------------------------=-:::: ~n--: ::-:=: ==-n-=---~:-:-:-:----a~~ ----------------------------:. --------==----~--=---=---------------.0: -------------__ -_-__ -:'. ----=-----------,..-----------=--=--=--=-----:...---------------:...---------------------..:-:-=-:--:~----ra--:-~-D---:-~-=-==n-----:=-:=-':--:-:::: ------------------------------------------------------------------=-------~--------=:. ---------:...---:...-~-----------
---::I o· MIN;.---~-------------=-----------=---~~--=---=------~-------=--=----:-. ------~--------------A· MIN ----15' MIN ---_--=--_-_____ -=-. ----~--------------.'-. ----------------~-----------------=-----:....~------------:::----------=-----_-:. -----------------------------------_. --: -~ -==--~------::-::----Q----:-_:-=-:-:---:-:-:---------------------------------------------------------------------------
=-------~-:-OV~fsl~-:-:-::-:-:::---:----:----: =-:--:---:.~-JETTED OR FLOODED
_-=-Lo.. ==-~WINDROW =-: =-==_-;:::_--::-::-----------, GRANULAR MATERIAL
• 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 flU. ELEVATION A·A' ,
PROFILE ALONG WINDROW
JErrED OR FLOODED
GRANULAR MATERIAL
OVERSIZE
ROCK DISPOSAL
_A--_-_---
GENERAL EARTHWORK AND GRADING mrlJ
SPECIFICATIONS U
STANDARD DETAILS B'
NATURAL
~GROUND ".
BENCHING ----t REMOVE
,.r..:::"l~ __ UNSUITABLE
MATERIAL
CAL TRANS CLASS II
PERMEABLE OR #2 ROCK
(9FT.31FT.) WRAPPED IN
FILTER FABRIC
FILTER FABRIC
i':.1':~~~ OR" COLLECTOR. PIPE SHALL
EQUIVALENl) BE MINIMUM 6" DIAMETER
SCHEDULE 40 PVC PERFORATED
CANYON SUBDRAIN OUTLET DETAIL PIPE. SEE STANDARD DETAIL D
DESIGN
FINISHED
GRADE
PERFORATED PIPE 6-. MIN.
-
~20'MIN.~
NON·PERFORATED S'MIN. 6-. MIN.
CANYON SUBDRAINS
FOR PIPE SPECIFICATION
FILTER FABRIC
(MIRAFt 140 OR
APPROVED
EQUIVALENl)
#2 ROCK WRAPPED IN FILTER
FABRIC OR CALTRANS CLASS II
PERMEABLE.
GENERAL EARTHWORK AND GRADING []ITJ
SPECIFICATIONS Ci u
STANDARD DETAILS C .
<4195
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OUTLET PIPES
4841 NON·PERFORATED PIPE,
100' MAX. O.C. HORIZONTAll V,
30' MAX. O.C. VERTICAll V -...... -BACKCUT 1:1
~-.-OR FLATTER
• SUBDJ:WN INSTALLATION -Subdrain collector pipe shall be Installed with perforations down or,
unless otherwise designated by the geotechnical consultant. Outlet pipes shall be non-perforated
pipe. The subdrain pipe shall have at least 8 perforations uniformly spaced per foot. Perforation shalf
be %. to ¥". If drilled holes are used. All subdrain pipes shall have.a gradient $ least 2% tawards the
outlet.
• SUBDRAfN PIPE -Subdrain pipe shall be ASTM 02751, SDR 23.5 or ASTM 01527, Schedule 40, or
ASTM D3034, SDR 23:5, Sched~le 40 Polyvinyl Chloride Plastic (PVC) pipe.
• All outlet pipe shall be placed In a trench no wider than twice the subdrain pipe. Pipe shall be in soli
of SE>30 jetted or flooded in place except for the outside 5 feet which shall be native soil backfill.
BUTTRESS OR
REPLACEMENT FILL
SUBDRAINS .
GENERAL EARTHWORK AND GRADING rlfi. ~[TI SPECIFICATIONS U
STANDARD DETAILS D
I
RETAINING WALL DRAINAG'E DEtAIL
RETAINING WALL
WALL: WATERPROOFING
PER ARCHIT'ECT'S'
SPEciFICA TI,ONS' -__ _
FINISH GRADE;
SOIL BACKFI.LL, COMPACTED TO
90 PERCENTjRELATIVE COMPACTION*
,3/4":"'1~1/2" CLEAN GRAVEL ** " • ." " ••• '.<:.
,£:.(MINJ=riiAMET,ER ,PE'RFORATED ~PVC 'PI'Pe,:(SCHEDULE 40 ORi' -
.~-=~-==-~-:::-:-:=~-==-=-==-=~-=-::-===-====:=::-==-==---=-=
EQU:'.yAL~~Tj ,v(,r.~,~ER~QaATIONS
,Q~IENTEDIDOWN,IAS DEPICTED: MINi~UM-'1jjERbENT"GR'A"OIENT: ~==~~~~~~~~~~~:fmI1f4i TO S'UIT A'~LE OUTLI~'" .' . ,.
W ALL FOOTING :----1--..-
NO·T TO SCALE
'SPECIFICATIONS FOR CALTRANS
CLASS 2 PERMEABLE MATERIAL
u.S. Standard
Sieve Size
1"
3/4"
3/8"
No. 4
No. 8
No. 30
No. 50
No. 200
% Passing
100
90-100
40-100
25-40
18-33
5-15
0-7
0-3
Sand Equivalent>75
COMPEtENT' BEDRock OR MATERIAL'
AS EVALUATED BY 'THE G'EOTECHNICAL
CONSUL TANT'
*BASED ON ASTM 01667
* * IF CAL TRANS CLASS 2 PERMEABLE MATERIAL
(SEE GRADATION TO LEFT) IS USED IN PLACE OF
3/4--1-112-GRAVEL. FILTER FABRIC MAY BE
DELETED. CAL TRANS CLASS 2 PERMEABLE-
MATERIAL SHOULD BE COMPACTED TO 90
PERCEN'f.1RElATIVE COMPACTION * '
NOTE:COMPOSITE DRAINAGE PRODUCTS SUCH AS MIRADRAIN
OR J-DRAIN MAY BE USED AS AN ALTERNA11VE TO GRAVEL OR
CLASS 2.INSTALLA 110N SHOULD BE PEAFORM3) IN ACCORDANCE
Wffi:I MANUFACTURER'S SPEORCATIONS.
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***********************
*
*
*
*
*
E Q F A U L T
Version 3.00
*
*
*
*
*
***********************
DETERMINISTIC ESTIMATION OF
PEAK ACCELERATION FROM DIGITIZED FAULTS
II JOB NUMBER: 040382-001
DATE: 03-20-2001
I JOB NAME: Carltas/Carlsbad Office Campus
CALCULATION NAME: Test Run Analysis
I FAULT-DATA-FILE NAME: CDMGFLTE.DAT
SITE COORDINATES:
SITE LATITUDE: 33.1262
117.3263 I SITE LONGITUDE:
SEARCH RADIUS: 100 mi
I ATTENUATION RELATION: 2) Boore et al. (1997) Horiz. -NEHRP C (520)
UNCERTAINTY (M=Median, S=Sigma): S Number of Sigmas: 1.0
DISTANCE MEASURE: cd_2drp
SCOND: 0
I Basement Depth: 1.00 km Campbell SSR:
COMPUTE PEAK HORIZONTAL ACCELERATION
FAULT.-DATA FILE USED: CDMGFLTE.DAT I MINIMUM DEPTH VALUE (Jan): O. 0
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Campbell SHR:
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EQFAULT SUMMARY
DETERMINISTIC SITE PARAMETERS
I Page 1 -------------------------------------------------------------------------------
I I IESTlMATED MAX. EARTHQUAKE EVENT
I APPROXIMATE 1-------------------------------
ABBREVIATED I DISTANCE I MAXIMUM I PEAK lEST. SITE
FAULT NAME I mi (Jan) I EARTHQUAKE I SITE I INTENSITY
I I I MAG. (Mw) I ACCEL. g IMOD.MERC.
================================ ==============1==========1==========1=========
ROSE CANYON 4.0 ( 6.5) I 6.9 I 0.536 I X
NEWPORT-INGLEWOOD (Offshore) 6.3 ( 10.1) I 6.9 I 0.425 I X
I CORONADO BANK 20.1 ( 32.4) I 7.4 I 0.245 I IX
ELSINORE-TEMECULA 25.0( 40.3) I 6.8 I 0.151 I VIII
ELSINORE-JULIAN 25.1 ( 40.4) I 7.1 I 0.177 I VIII
ELSINORE-GLEN IVY 35.7 ( 57.5) 6.8 I 0.115 I VII
I PALOS VERDES 37.0( 59.6) 7.1 I 0.131 I VIII
EARTHQUAKE VALLEY 43.2 ( 69.6) 6.5 I 0.085 I VII
SAN JACINTO-ANZA '47.8 ( 76.9) 7.2 I 0.114 I VII
NEWPORT-INGLEWOOD (L.A.Basin) 48.0( 77.2) 6.9 I 0.097 I VII
I SAN JACINTO-SAN JACINTO VALLEY 48.6( 78.2) 6.9 I 0.096 I VII
CHINO-CENTRAL AVE. (Elsinore) 49.1 ( 79.0) 6.7 I 0.104 I VII
SAN JACINTO-COYOTE CREEK 52.6( 84.6) 6.8 I 0.085 I VII
WHITTIER 53.4( 85.9) 6.8 I 0.084 I VII
I ELSINORE-COYOTE MOUNTAIN 56.9( 91. 6) 6.8 I 0.080 I VII
COMPTON THRUST 57.6( 92.7) 6.8 I 0.097 I VII
ELYSIAN PARK THRUST 60.4 ( 97.2) 6.7 I 0.089 I VII
SAN JACINTO-SAN BERNARDINO 61.7 ( 99.3) 6.7 I 0.072 I VI
I SAN JACINTO -BORREGO 65.7 ( 105.8) 6.6 I 0.065 I VI
SAN ANDREAS -San Bernardino 66.4 ( 106.8) 7.3 I 0.093 I VII
SAN ANDREAS -Southern 66.4 ( 106.8) 7.4 I 0.098 I VII
SAN JOSE 70.2 ( 113.0) 6.5 I 0.071 I VI
I CUCAMONGA 72.8 ( 117.2) 7.0 I 0.090 I VII
SIERRA MADRE 72.9 ( 117.3) 7.0 I 0.090 I VII
PINTO MOUNTAIN 73.3( 117.9) 7.0 I 0.073 I VII
SAN ANDREAS -Coachella 74.1( 119.2) 7.1 I 0.077 I VII
I NORTH FRONTAL FAULT ZONE (West) 77.2 ( 124.3) 7.0 I 0.086 VII
BURNT MTN. 78.9( 127.0) 6.4 I 0.051 VI
CLEGHORN 79.4 ( 127.8) 6.5 0.053 VI
NORTH FRONTAL FAULT ZONE (East) 81. 5 ( 131.1) 6.7 0.070 VI
I EUREKA PEAK 81.6( 131. 4) 6.4 0.049 VI
SUPERSTITION MTN. (San Jacinto) 81. 8 ( 131. 6) 6.6 0.055 VI
RAYMOND 82.0( 131. 9) 6.5 0.063 VI
CLAMSHELL-SAW PIT 82.3( 132.4) 6.5 0.063 VI
I SAN ANDREAS -1857 Rupture 82.7 ( 133.1) 7.8 0.102 VII
SAN ANDREAS -Mojave 82.7 ( 133.1) 7.1 0.070 VI
VERDUGO 84.3 ( 135.7) 6.7 0.068 VI
ELMORE RANCH 85.4 ( 137.5) 6.6 0.053 VI
I HOLLYWOOD 86.2 ( 138.8) 6.4 0.057 VI
SUPERSTITION HILLS (San Jacinto) 86.5( 139.2) 6.6 0.052 VI
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I Page 2
I ABBREVIATED
FAULT NAME
DETERMINISTIC SITE PARAMETERS
IESTIMATED MAX. EARTHQUAKE EVENT
APPROXIMATE 1-------------------------------
DISTANCE I MAXIMUM I PEAK lEST. SITE
mi (km) I EARTHQUAKE I SITE I INTENSITY
I I I MAG. (Mw) I ACCEL. g I MOD. MERe.
================================ ==============1==========1==========1=========
LAGUNA SALADA 88.0( 141.7) I 7.0 I 0.064 I VI
LANDERS 88.9( 143.1) I 7.3 I 0.074 I VII
I HELENDALE -S. LOCKHARDT
SANTA MONICA
MALIBU COAST
LENWOOD-LOCKHART-OLD WOMAN SPRGS
I BRAWLEY SEISMIC ZONE
JOHNSON VALLEY (Northern)
EMERSON So. -COPPER MTN.
SIERRA MADRE (San Fernando)
I NORTHRIDGE (E. Oak Ridge)
ANACAPA-DUME
SAN GABRIEL
90.0( 144.8) I 7.1 I 0.066 I VI
9loO( 146.4) I 6.6 I 0.061 I VI
93.7 ( 150.8) I 6.7 I 0.063 I VI
93.8 ( 150.9) I 7.3 I 0.071 I VI
94.9 ( 152.8) I 6.4 I 0.044 I VI
96.8( 155.8) I 6.7 I 0.050 I VI
97.0( 156.1) I 6.9 I 0.056 I VI
97.3( 156.6) I 6.7 I 0.061 I VI
97.5( 156.9) I 6.9 I 0.068 I VI
98.9( 159.2) I 7.3 I 0.083 I VII
99.1( 159.5) I 7.0 I 0.058 I VI
******************************************************************************* II -END OF SEARCH-53 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS.
THE ROSE CANYON FAULT IS CLOSEST TO THE SITE.
IT IS ABOUT 4.0 MILES (6.5 km) AWAY. II LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.5364 g
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