HomeMy WebLinkAboutCUP 08-15; FIRST RESPONDERS TRAINING FACILITY; GEOTECHNICAL UPDATE INVESTIGATION; 2008-07-31I
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GEOTECHNICAL UPDATE INVESTIGATION,
PROPOSED CARLSBAD FIRST RESPONDER'S JOINT-USE
TRAINING FACILITY,
CARLSBAD, CALIFORNIA
Prepared For:
RRM Design Group
232 Avenida Fabricante, Suite 112
San Clemente, CA 92672
Project No. 602256-001
July 21, 2008
Leighton Consulting, Inc. ---
A LEIGHTON GROUP COMPANY
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Leighton Consulting, Inc.
A LEIGHTON GROUP COMPANY
July 21, 2008
Project No. 602256-001
To: RRM Design Group
232 Avenida Fabricante, Suite 112
San Clemente, CA 92672
Attention: Mr. Don Iler A.I.A.
Subject: Geotechnical Update Investigation, Proposed Carlsbad First Responder's Joint-
Use Training Facility, Carlsbad, California ·; '
In accordance with your request and authorization, we have conducted a geotechnical update
investigation of the proposed Carlsbad First Responder's Joint-Use Training Facility, located at
2560 Orion Way in Carlsbad, California. Based on the resuhs· of our study, it is our professional
opinion that the site is suitable for a proposed development and improvements provided that the
recommendations presented herein are incorporated into the design, grading, and construction of
the site. The accompanying report presents a summary of oui investigation and provides
preliminary 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 ofservice:
Respectfully submitted,
LEIGHTON CONSULTING, INC.
Willian1 D. Olson, RCE, 4528
Associate Engineer
Distribution: ( 6) Addressee
.-.All/ w ~~a'fi'~ ag~G 161:2 "·
riricipal Geologist .
3934 Murphy Canyon Road, Suite 8205 • San Diego, CA 921234425
858.292.8030 • Fax 858.292.0771
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602.2.56-001
TABLE OF CONTENTS
Section
1.0 INTRODUCTION .......................................................................................................... 1
1.1 PURPOSE AND SCOPE ............................................................................................... 1
1.1.1 Scope of Work ................................................................................................. 1
1.2 SITE LOCATION AND DESCRIPTION .............................................................................. 3
1.3 PREVIOUS SITE DEVELOPMENT ................................................................................... 3
1.4 PROPOSED DEVELOPMENT ......................................................................................... 3
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING .............................................. 5
3.0 SUMMARY OF GEOTECHNICAL CONDffiONS .................................................................. 6
3.1 GEOLOGIC SETTING ................................................................................................. 6
3.2 SITE-SPECIFIC GEOLOGY ........................................................................................... 6
3.2.1 Artificial Fill-nonstructural (Map Symboi-Afn) .................................................. 6
3.2.2 Topsoil/ Colluvium (Map Symboi-Qcol) ............................................................... 7
3.2.3 Lusardi Formation (Map Symboi-KI) ................................................................... 7
3.3 GEOLOGIC STRUCTURE ............................................................................................. 8
3.4 SURFACE AND GROUND WATER ................................................................................... 8
3.5 LANDSUDES ........................................................................................................... 8
3.6 FLOOD HAZARD ...................................................................................................... 9
3.7 ENGINEERING CHARACTERISTICS OF ON-SITE SOILS ......................................................... 9
3.7.1 Expansion Potential ........................................................................................... 9
3. 7.2 Excavation Characteristics .................................................................................. 9
3.7.3 Earthwork Shrinkage and Bulking ...................................................................... ll
3. 7.4 Soil Corrosivity ............................................................................................... 12
4.0 FAULTING AND SEISMICITY ....................................................................................... 13
4.1 FAULTING ............................................................................................................ 13
4.2 SEISMICITY .......................................................................................................... 13
4.2.1 Shallow Ground Rupture ................................................................................. 13
4.2.2 Liquefaction ................................................................................................... 14
4.2.3 Earthquake-Induced Settlement ....................................................................... 14
4.2.4 Lateral Spread ................................................................................................ 14
4.2.5 Tsunamis and Seiches ..................................................................................... 15
4.2.6 Building Code Seismic Parameters ..................................................................... 15
5.0 CONCLUSIONS .......................................................................................................... 16
6.0 RECOMMENDATIONS .................................................................................................. 18
6.1 EARTHWORK ........................................................................................................ 18
6.1.1 Site Preparation .............................................................................................. 18
6.1.2 Removal and Recompaction ............................................................................ 18
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TABLE OF CONTENTS
Section
6.1.3 Excavations and Oversize Material ................................................................... 19
6.1.4 Fill Placement and Compaction ........................................................................ 19
6.1.5 Transition Mitigation ....................................................................................... 20
6.1.6 Expansive Soils and Selective Grading .............................................................. 20
6.1.7 Import Soils ................................................................................................... 21
6.2 SURFACE DRAINAGE AND EROSION •••••••••••••••••••••..••••••••..••••••••.•••••••••••••••••••••••••.•••••••• 21
6.3 FoUNDATION AND SLAB CONSIDERATIONS ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 21
6.3.1 Foundations ................................................................................................... 22
6.3.2 Slabs ............................................................................................................. 22
6.3.3 Settlement ..................................................................................................... 23
6.3.4 Lateral Pressures and Shoring Design ............................................................... 24
6.4 PRELIMINARY PAVEMENT DESIGN ............................................................................... 25
6.5 CONSTRUCTION OBSERVATION AND TESTING AND PLAN REVIEW .••••••••••••••••••••••..•••••••••••••••• 26
7.0 UMITATIONS ............................................................................................................ 27
TABLES
TABLE 1 -EARTHWORK SHRINKAGE AND BULKING ESTIMATES-PAGE 12
TABLE 2-CBC SEISMIC DESIGN PARAMETERS-PAGE 15
TABLE 3-STATIC EQUIVALENT FLUID WEIGHT (PCF) -PAGE 24
TABLE 4-PRELIMINARY ASPHALT PAVEMENT DESIGN-PAGE 25
FIGURE
FIGURE 1 -SITE LOCATION MAP-PAGE 2
FIGURE 2 -GEOTECHNICAL MAP -REAR OF TEXT
APPENDICES
APPENDIX A -REFERENCES
APPENDIX B-BoRING LOGS AND ExPLORATION TRENCH LOGS
APPENDIX C-lABORATORY DATA ANALYSIS
APPENDIX D-SEISMIC REFRACTION SURVEY
APPENDIX E-GENERAL EARTHWORK AND GRADING SPEOFICATIONS
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1.0 INTRODUCTION
Purpose and Scope
This report presents the results of our geotechnical update investigation of the proposed
Carlsbad First Responder's Joint-Use Training Facility located at 2560 Orion Way in tbe
City of Carlsbad, California. (see Figure 1). Our investigation included geotechnical
exploration of the site, laboratory testing of selected soil samples, geotechnical analysis of
the data collected, and preparation of this report. The purpose of our geotechnical
investigation was to evaluate existing geotechnical conditions present at the site and to
provide preliminary conclusions and geotechnical recommendations relative to tbe
proposed development of tbe property.
1.1.1 Scope of Work
As part of our geotechnical investigation, we performed the following:
• Review of available pertinent, published, and unpublished geotechnical
literature maps, and aerial photographs (Appendix A).
• Review of the previous investigation and as-graded reports (Leighton, 200 I),
and conceptual site development plans by RRM Design Group (RRM, 2008).
• Field reconnaissance oftbe existing onsite geotechnical conditions.
• Coordination witb Underground Services Alert (USA) to locate potential
underground utilities on or adjacent to the site.
• Subsurface exploration consisting of the excavation, logging, and sampling of
9 hollow-stem auger borings. The approximate borings are shown on the
Geotechnical Map (Figure 2). The logs of tbe borings are presented in
Appendix B.
• Laboratory testing of representative soil samples obtained from tbe subsurface
exploration. Results of tbese tests are presented in Appendix C, witb the
exception of moisture/density determinations, which are provided on tbe
boring logs (included in Appendix B).
• Compilation and analysis of tbe geotechnical data obtained from tbe field
investigation and laboratory testing (including the prior seismic refraction
survey presented in Appendix D).
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Carlsbad First Responder's
Joint-UseTraining Facility
City of Carlsbad, California
SITE LOCATION
MAP
~
N
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0 2,000 4,000
SCALE FEET
Base Map: AerialsExpress, GDT-Teleatlas Street Data,
Spring 2005
Project No.
602256-001
Date
July 2008 Figure 1
1\GIS\Adminislnlllon\An:GISTifT'Illltesy.jEW_GOT_SleLoc:.olionMap.ITI>Cf
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602256-001
• Review local and regional seismicity, and provide seismic parameters for the
site in accordance with 2007 California Building Code (CBC).
• 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 site, which is bounded by Orion Way on the north, south and east sides, and Orion
Street to the west is located in the east-central portion of Carlsbad, California (Figure 1 ).
Currently, the site is being used as an athletic field (baseball and soccer) with minor fill
slopes at the north-eastern and south-western corners. At the eastern end of the site, there
is an elevated grassy area with trees and large exposed landscape boulders. Topography of
the athletic field is generally flat with elevations ranging from approximately 351 feet to
357 feet mean sea level (msl) at the western and eastern ends, respectively. The elevation
of the elevated grassy area is approximately 365 feet msl.
Previous Site Development
The original mass-grading of the general site was performed in 1985 and generally
consisted of cuts and fills for the existing buildings and parking areas, and infilling of the
previously existing canyon located in the southeast portion of the Carlsbad Public Works
Facility. Reportedly, uncontrolled artificial fill containing oversize materials (i.e.
boulders) was placed at the subject site (the athletic field and the elevated grassy area)
within the area bounded by Orion Way and Orion Street. In 1988, rough grading for the
existing City of Carlsbad Fire Station No. 5 and the existing skate park located at the
southern portion of the site was performed. As background, the grading operations for the
existing fire station were performed during July and August, 1988 under the observation
of Leighton and Associates, Inc. (Leighton, 1988).
Proposed Development
Based on our review of the conceptual site development plans, prepared by RRM, dated
May 2008, we understand that the proposed development consists of a total area of
approximately 4.3 acres. The proposed training facility will consist of four major
elements: a Residential Burn Prop Structure, a Commercial Burn Prop Structure (with a
multi-story training tower), a classroom and shooting range building, and a one-to two-
story Fire Administration building.
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602256-001
We are assuming that the buildings and training structures will be constructed with
masonry or concrete walls. Other proposed improvements consist of training pavement
areas adjacent to the buildings, court yards, sidewalks, underground utilities, and
landscape areas. Proposed grades of the development are assumed to remain at or near the
present elevations.
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602256-001
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING
Our recent subsurface investigation consisted of the excavation of nine (9) small-diameter
exploratory borings. The purpose of these excavations was to evaluate the engineering
characteristics of the onsite soils with regard to the proposed development. The borings allowed
evaluation of the onsite soils, including those likely to be encountered at the proposed foundation
elevations and provided representative samples for laboratory testing.
The exploratory excavations were logged by a representative from our firm. Representative bulk
and relatively undisturbed samples were obtained at frequent intervals for laboratory testing. The
approximate locations of the borings are shown on the Geotechnical Map (Figure 2). Subsequent
to logging and sampling, the borings were backfilled with bentonite in general accordance with
the County of San Diego, Department of Environmental Health (DEH) requirements.
Laboratory testing was performed on representative samples to evaluate moisture and density,
soil strength parameters, hydraulic conductivity (permeability), and geochemical 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).
It should be noted that a previous subsurface investigation and geotechnical study of the site and
an area north of the site was performed by Leighton in 2001. As part of that previous study, two
trenches, T-3 and T-4, were excavated, sampled and logged in the vicinity of the currently
proposed improvements. Depths of trenches ranged from 5 to 8 feet below the existing ground
surface (bgs). Trench logs are presented in Appendix B.
In addition, a seismic refraction survey was performed by Subsurface Surveys for the previous
study. The refraction survey consisted of eight seismic traverses, of which four seismic traverses
(Lines 5, 6, 7 and 8) are within the current study area (Leighton, 2001). The seismic refraction
survey report is presented in Appendix D. The approximate locations of the previous trenches
and seismic traverses are shown on the Geotechnical Map (Figure 2).
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3.0 SUMMARY OF GEOTECHNICAL CONDmONS
Geologic Setting
The subject site is located in the coastal section of the Peninsular Range Province, a
geomorphic province with a long and active geologic history throughout Southern
California. The area known as the "San Diego Embayment" has undergone several
episodes of marine inundation and subsequent marine regression, resulting in the
deposition of a thick sequence of marine and nonmarine sedimentary rocks on the
basement rock of the Southern California batholith.
Gradual emergence of the region from the sea occurred in Pleistocene time, and numerous
wave-cut platforms, most of which were covered by relatively thin marine and nonmarine
terrace deposits, formed as the sea receded from the land. Accelerated fluvial erosion
during periods of heavy rainfall, coupled with the lowering of the base sea level during
Quaternary time, resulted in the rolling hills, mesas, and deeply incised canyons which
characterize the landforms we see in the general site area today.
Site-Specific Geology
Based on our subsurface exploration, and review of pertinent geologic literature and
maps, the site is generally overlain by undocumented artificial fill soils which is underlain
by topsoil/colluvium and/or bedrock material consisting of the Lusardi Formation. A brief
description of the geologic units as encountered on the site is presented below. The
approximate aerial distributions of these units are shown on the Geotechnical Map
(Figure 2).
3.2.1 Artificial Fill-nonstructural (Map Symbol Afn)
Based on our review of the as-graded geotechnical report for the site, we
understand that placement of uncontrolled nonstructural artificial fill was
generally limited to the present ball field and grassy area within the area bounded
by Orion Way and Orion Street. The approximate limits of uncontrolled
nonstructural fill are shown on the Geotechnical Map (Figure 2). As encountered
during our investigation, the nonstructural fill soils generally consist of dry to
moist; loose to dense; clayey, silty sand with scattered gravel. Nonstructural fill
soils were encountered to depths ranging from approximately 2 to 5 feet bgs in the
Borings and previous Trenches T-3 and T-4 (Appendix B); however, deeper fills
may exist and could be encountered during site grading.
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602256-001
Note that it is our understanding that this area was also utilized for stockpiling
oversize materials during grading and that the stockpile was covered with
uncontrolled fill near the completion of grading (Geocon, 1985). These non-
structural fill soils are considered potentially compressible in their current state
and will require complete removal and recompaction within the limits of site
grading. These soils appear to be suitable for use as fill provided they are
relatively free of rocks (larger than 8-inches in maximum dimension) organic
material, and deleterious debris. Special handling recommendations for oversize
material are included in Appendix E.
3.2.2 Topsoil/Colluvium CMap Symboi-Ocol)
As encountered, the topsoil/colluvium on the site consists of dark gray, dark
brown to brown and yellow, moist to damp, stiff sandy clay and loose to very
dense, slightly clayey silty sand with some organic debris. Observations also
indicated that the lower portion of this unit was locally porous. In general, the
topsoil/colluvium was found to be generally indistinguishable in the upper portion
of this unit. This material was found underlying undocumented fill soils in
Trenches T-3 and T-4 and is likely to be present in other areas of the site. In
general, the topsoil/colluvial soils were found to range from I to 3.5 feet in
thickness. However, the deeper accumulation of this unit could be encountered.
To supplement our previous 200 I subsurface investigation, a seismic refraction
survey was performed, as described in Section 3.7.2 of this report. The results of
the seismic refraction survey within the subject site indicate the thickness of the
uncontrolled fill and topsoil/colluvium varies from approximately 3 to 12 feet in
the vicinity of Line 5 through 8 (Appendix D).
In general, the topsoil/colluvium is considered potentially compressible and not
suitable for support of the proposed improvements. This material will need to be
removed to competent formational material in areas of proposed improvements. It
should also be noted that the clayey portions of this material may have a high
expansion potential (Leighton, 200 I).
3.2.3 Lusardi Formation CMap Symboi-KI)
The Cretaceous-aged Lusardi Formation underlies the site at depth and is
considered to be the primary bedrock unit at the site. The Lusardi Formation is
generally composed of light brown to gray brown, and orange to red-brown; very
dense; gravel to cobble and boulder conglomerate with a medium to coarse
sandstone matrix. The gravel to boulder clasts in this unit are predominately
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602256-001
composed of granitic material derived from the underlying granitic bedrock. The
Lusardi Formation generally mantels the underlying granitic bedrock and locally
contains large to very large (up to 10 to 20 feet in diameter) granitic boulders.
These granitic boulders are commonly very dense and, if encountered, may cause
excavation difficulties during grading. Although not believed to be common, local
beds of claystone and siltstone may also be encountered in this unit.
The Lusardi Formation is generally expected to exhibit favorable engineering
properties. Excavation of this material may be difficult in areas; however, based
on our review of the proposed site plans, deep cuts in this unit are not anticipated.
If oversized materials are generated during grading they should be handled in
accordance with the recommendations presented herein and in Appendix E of this
report.
Geologic Structure
The Lusardi Formation bedrock encountered on the site was generally massive with no
apparent bedding.
Surface and Ground Water
No indication of surface water or evidence of surface ponding was encountered during
our field investigation. However, surface water may drain as sheet flow across the sheet-
graded pad during rainy periods and accumulate in lower elevations of the site.
Ground water was not observed in the borings during our investigation; however, perched
ground water should be anticipated on top of the Lusardi Formation and may fluctuate
during periods of precipitation. In addition, saturated areas and seepage along the
northern perimeter of the site (i.e., at the toe of the existing slope) may develop during
rainy periods. It should be noted that laboratory testing of the remolded fill soils (sample
remolded to approximately 90 percent relative compaction of ASTM 1557) indicate a
hydraulic conductivity on the order of 0.000021-cm/sec.
Landslides
No ancient landslides have been mapped on the subject site. In addition, no evidence of
landsliding was encountered during our site investigation. Based on the flat nature of the
site and our experience with similar conditions in the project vicinity, the potential for
landsliding is considered low.
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Flood Hazard
According to a Federal Emergency Management Agency (FEMA) flood insurance rate
map (FEMA, 1997), the site is not located within a flood zone. Based on review of dam
inundation and topographic maps per SANGIS, the site is not located downstream from
dam inundation areas.
Engineering Characteristics of On-site Soils
Based on the results of our geotechnical investigation, previous geotechnical
investigations of the site by others, laboratory testing of representative on-site soils, and
our professional experience on adjacent sites with similar soils, the engineering
characteristics of the on-site soils are discussed below.
3.7.1 Expansion Potential
The majority of the onsite soils are expected to have a low to moderate expansion
potential. However, clayey portions of the existing topsoil!colluvium were
previously tested to be highly expansive (Leighton, 2001). Geotechnical
observation and/or laboratory testing upon completion of the graded pads is
recommended to determine the actual expansion potential of finish grade soils on
the graded building pads. These materials should be placed at depths greater than
5 below pad grade and at least 3 feet below parking/drive areas, streets and/or
hardscape areas.
3.7.2 Excavation Characteristics
As part of the previous investigation for the site, a seismic refraction field study
was conducted on August I 0, 200 I. A total of I ,816 linear feet of data was
collected along eight seismic refraction lines. The purpose of these surveys was to
evaluate the approximate seismic velocities of the Lusardi Formation material in
order to provide a rough estimate of the rippability characteristics of the
formational materials. The approximate locations of the seismic survey lines are
presented on the Geotechnical Map (Figure 2) and the results presented in
Appendix D.
The seismic refraction method uses first-arrival times of refracted seismic waves to
determine the thickness and seismic velocities of subsurface materials. The seismic
waves were initiated at the ends of each survey line by striking an aluminum plate
with a 20-pound hammer. Seismic waves generated at the ground surface were
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reflected and refracted from boundaries separating materials of contrasting velocities
(or densities) and were detected by a series of twenty-four surface geophones placed
along the survey line. The waves detected by the geophones were recorded with a
Bison 9024, 24 channel seismograph. Time-distance plots and associated
geophysical interpretations of the seismic data from the eight survey lines were then
prepared and analyzed. The data is provided in Appendix D. It should be noted that
the measured seismic velocities presented on the plots represent average velocities
of the subsurface materials, and significant local variations due to buried boulders
(or "floaters"), localized hard or cemented zones concretions, or other anomalies
may be present.
In order to categorize the subsurface materials in terms of excavation
characteristics, the following classifications are utilized. This five-fold
classification scheme is based on our experience with similar rocks in the San
Diego County area, and assumes the use of a single shank D9L Dozer (or
equivalent equipment). The rippability characteristics of the site materials are
classified as follows:
Calculated Seismic Velocity
Up to 2000 feet per second
2000 to 4000 feet per second
4000 to 5500 feet per second
5500 to 7000 feet per second
Greater than 7000 feet per second
General Excavation Characteristic
Easy ripping
Moderately difficult ripping
Difficult ripping, possible localized
blasting
Very difficult ripping, probable local to
general blasting
Blasting required
"Difficult ripping" refers to rocks, in which it becomes difficult to achieve tooth
penetration, sharply reducing ripping production. Local blasting may be necessary in
order to maintain a desired ripping production rate. "Very difficult ripping" refers to
rocks in which the use of heavy construction equipment is likely to cease being a
cost-effective method of excavation (necessitating the use of explosives to maintain
a desired excavation rate). It should be emphasized that the cutoff velocities of this
classification scheme are approximate and rock characteristics (such as fracture or
joint spacing and orientation) play a significant role in determining rock rippability.
These characteristics may also vary with location and depth in the rock mass.
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The average seismic velocities of the underlying Lusardi Formation along the four
seismic survey lines varies from approximately 4585 to 5502. Based on the results
of the seismic refraction study, it appears that near surface materials are rippable
with heavy-duty construction equipment in good working order (i.e. a single shank
D9L Dozer or equivalent). Difficult ripping and possible localized blasting may be
required and should generally be limited to areas of deep utility excavations.
However, deep cuts into the Lusardi Formation are not anticipated during the
grading operations. If a significant amount of oversize material (typically rock over
8 inches in maximum dimension) is generated, it should be placed in accordance
with Section 6.1.2 of this report and Appendix E.
3.7.3 Earthwork Shrinkage and Bulking
Based on the results of our investigation and our professional experience with
similar projects in the general vicinity of the site, we have estimated bulking and
shrinkage of the on-site soils. The thickness of uncontrolled artificial fill is unknown
but anticipated to be on the order of 2 to 5 feet in depth. In addition, topsoil/colluvial
soils may underlie the uncontrolled artificial fill, and are generally anticipated to be
on the order of I to 4 feet thick.
The volume change of excavated onsite materials upon recompaction as fill is
expected to vary with materials and location. Typically, the surficial soils and
bedrock materials vary significantly in natural and compacted density, and
therefore, accurate earthwork shrinkage/bulking estimates cannot be determined.
However, the following factors (based on the results of our investigation,
geotechnical analysis and professional experience with similar materials) are
provided on Table I as guideline estimates. If possible, we suggest an area where
site grades can be adjusted (during the later portion of the site grading operations)
be provided as a balance area.
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Table 1
Earthwork Shrinka e and Bulkin Estimates
Geologic Unit Estimated Shrinkage/bulking
Undocumented Fill 5 to 15 percent shrinkage
Topsoil!Colluvium 0 to I 0 percent shrinkage
Lusardi Fonnation 4 to 12 percent bulking
3.7.4 Soil Corrosivitv
A preliminary corrosive soil screening for the on-site fill soil was performed to
evaluate the potential effect on concrete and ferrous metals.
Laboratory testing was performed on one representative sample to evaluate pH,
minimum electrical resistivity, and chloride and soluble sulfate contents. The
sample tested had a measured pH of 7.39, and a measured minimum electrical
resistivity of 6,000 ohm-em. Test results also indicated that the sample had a
chloride content of 84 ppm, and a soluble sulfate content of 180 ppm.
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4.0 FAULTING AND SEISMICilY
4.1 Faulting
Our discussion of faults on the site is prefaced with a discussion of California legislation
and state 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 (EFZ) as mandated by the Alquist-Priolo Earthquake Faulting
Zones Act of 1972 and as most recently revised in 1997 (Hart, 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. Based on our review, the site is not located within an EFZ,
(CGS, 2003).
A review of available geologic literature pertaining to the subject site indicates that there are
no known active regional faults that transect the subject site (Appendix A). The nearest
known active regional fault is the Rose Canyon Fault located approximately 7 miles west of
the site (Blake, 2000).
4.2 Seismicity
The principal seismic considerations for most structures in southern California are surface
rupturing of fault traces and damage caused by strong ground shaking or seismically
induced ground settlement. Historically, the San Diego region has been spared major
destructive earthquakes. The site is considered to lie within a seismically active region, as
can all of Southern California.
The effect of seismic shaking may be mitigated by adhering to the California Building
Code (see Section 4.2.6 of this report for CBC seismic parameters) or state-of-the-art
seismic design parameters of the Structural Engineers Association of California.
Secondary effects associated with severe ground shaking following a relatively large
earthquake can include shallow ground rupture, soil liquefaction, lateral spreading,
earthquake-induced settlement, and tsunamis/seiches. These secondary effects of seismic
shaking are discussed in the following sections.
4.2.1 Shallow Ground Rupture
No active or potentially faults are mapped transecting the site, and the site is not
located within a mapped EFZ (CGS, 2003). The nearest mapped active fault is the
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Rose Canyon Fault located approximately 7 miles west of the site. Ground cracking
due to shaking from distant seismic events is not considered a significant hazard
at the site, since the site is underlain at depth by dense sedimentary formation and
there are no significantly high slopes on the site or adjacent to the 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 manifested by sand boils, excessive settlement, and bearing
failure.
Bedrock materials at the site are not considered liquefiable due to either their high
density or unsaturated conditions. Surficial materials including undocumented fill
and topsoil/ colluvium are recommended for removal and replacement with
compacted engineered fill material. Properly compacted engineered fill is not
considered to be liquefiable.
4.2.3 Earthquake-Induced Settlement
Granular soils tend to densify when subjected to shear strains induced by ground
shaking during earthquakes. Simplified methods were proposed by Tokimatsu and
Seed (1987) and Ishihara and Yoshimine (1991) involving SPT N-values used to
estimate earthquake-induced soil settlement.
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 settlement
are expected to be negligible.
4.2.4 Lateral Spread
Empirical relationships have been derived by Y oud and others (Y oud, 1993;
Bartlett and Youd, 1995; and Youd et. al., 1999) to estimate the magnitude of
lateral 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.
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Since the potential for liquefaction at the site is low, the susceptibility to
earthquake-induced lateral spread is also considered to be low.
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 nil.
4.2.6 Building Code Seismic Parameters
The following table below presents geotechnical design parameters that have been
determined in accordance with the 2007 CBC (CBSC, 2007).
Table 2
CBC Seismic Design Parameters
Description Values CBC Reference
Site Class c Table 1613.5.2
Short Period Spectral Acceleration S, 1.300 Figure 1613.5(3)
!-Second Period Spectral Acceleration s, 0.491 Figure 1613.5(4)
Short Period Site Coefficient F, 1.0 Table 1613.5.3(1)
!-Second Period Site Coefficient Fv 1.309 Table 1613.5.3(2)
Adjusted Short Period Spectral Acceleration SMs 1.300 Equation 16-3 7
Adjusted !-Second Period Acceleration SMI 0.642 Equation 16-38
Design Short Period Spectral Response Parameter Sos 0.866 Equation 16-3 9
Design !-Second Period Spectral Response Parameter SDI 0.428 Equation 16-40
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5.0 CONCLUSIONS
Based on the results of our geotechnical investigation of the site, it is our professional opinion
that the proposed development of the site is feasible from a geotechnical standpoint, provided the
following conclusions and recommendations are incorporated into the design, grading, and
construction of the project. The following is a summary of the geotechnical factors that may
affect development of the site.
• Based on our reference review, subsurface exploration, and laboratory testing, uncontrolled
nonstructural artificial fill was placed during the 1985 rough grading of the site. In addition,
potentially compressible topsoil/colluvium was left-in-place and currently underlies the
uncontrolled fill in various areas. The uncontrolled fill, topsoil/colluvium are considered
potentially compressible in their current state and will require complete removal to competent
formational material in areas of proposed settlement sensitive improvements.
• In general, the on-site soils appear to be suitable for reuse as fill provided they are relatively
free of rocks (larger than 8-inches in maximum dimension) organic material, and deleterious
debris.
• Near surface materials are considered rippable with heavy-duty construction equipment in
good working order (i.e. a single shank D9L Dozer or equivalent). Difficult ripping and
possible localized blasting may be required and should generally be limited to areas of deep
utility excavations. Excavations exceeding I 0 feet within the Lusardi Formation may require
very heavy ripping and probable local to general blasting. However, deep cuts into the
Lusardi Formation are not anticipated during the grading operations.
• Oversized material (requiring specialized handling) may be generated during demolition of
the existing improvements, excavation within the Lusardi Formation, and grading operations
within uncontrolled (nonstructural) fill areas.
• The uncontrolled fill soils and soils of the Lusardi Formation are anticipated to have a low to
medium expansion potential.
• Clayey topsoil and colluvial soils may be moderately to highly expansive and are not
recommended for use as compacted fill below proposed building areas, as subgrade material for
the parking and drive areas, or as retaining wall backfill.
• Laboratory test results indicate that fill soil present on the site have a negligible potential for
sulfate attack concrete and a relatively mild or low potential for corrosion to buried uncoated
metal conduits. Additional laboratory testing should be performed during grading.
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• Ground water was not encountered during our investigation. Although not encountered
during our investigation, perched ground water may occur locally on top of the Lusardi
Formation, particularly after periods of heavy rainfall or irrigation. Groundwater is not
expected to significantly impact the proposed development provided the recommendations
regarding drainage outlined in this report are implemented.
• The site is located in an area underlain by the Lusardi Formation that is known to contain both
permeable and impermeable layers which can transmit and perch ground water in unpredictable
ways. Therefore, given the site geologic conditions, Low Impact Development (LID) measures
may impact down gradient area, which include existing improvements (buildings and utilities)
and potential future developments adjacent properties. Therefore, the use of some LID measures
may not be appropriate for this project.
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6.0 RECOMMENDATIONS
Earthwork
We anticipate that earthwork at the site will consist of site preparation, minor cuts and
fills and underground utility excavation. 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 E of this report. In
case of conflict, the following recommendations shall supersede those in Appendix E 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 nonstructural, undocumented or loose fill soils, and stripped of
vegetation. Removed vegetation and debris should be properly disposed off site.
Holes resulting from removal of buried obstructions that extend below finish
grades should be replaced with suitable compacted fill material. All areas to
receive fill and/or other surface improvements should be scarified to a minimum
depth of 6 inches, brought to at least 2 percent above near-optimum moisture
conditions, and recompacted to at least 90 percent relative compaction (based on
ASTM Test Method 01557).
6.1.2 Removal and Recompaction
The existing undocumented fills, nonstructural fill soils, and topsoil/colluvium are
considered potentially compressible and are not suitable for support of the
proposed improvements. Where not removed by the planned grading, these soils
should be excavated to competent formational material bedrock as determined by
Leighton. The removal bottom should be moisture-conditioned and recompacted
to a minimum 90 percent relative compaction (based on ASTM Test Method
01557) prior to placing fill. The removal limit should be established by a 1:1
projection from the edge of fill soils supporting settlement-sensitive structures
downward and outward to competent material identified by the geotechnical
consultant. In general, we anticipate the depth of removals to be on the order of 2
to + 1 0 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.
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6.1.3 Excavations and Oversize Material
Shallow excavations of the onsite materials may generally be accomplished with
conventional heavy-duty earthwork equipment. Based on the results of the seismic
refraction study and our review of previous geotechnical reports, excavations
exceeding 10 feet with the Lusardi Formation may require very heavy ripping
and/or blasting and may result in the generation of some oversize material. In
addition, cemented zones and granitic floaters may likely be encountered in
deeper excavation within this unit.
Due to the high-density characteristics of the onsite Lusardi Formation, temporary
excavations such as utility trenches with vertical sides in these units should
remain stable for the period required to construct the utility, provided they are free
of adverse geologic conditions. Undocumented and nonstructural artificial fill and
topsoil/colluvial soils present on site may cave during trenching operations. In
accordance with OSHA requirements, excavations deeper than 5 feet should be
shored or be laid back if workers are to enter such excavations. Temporary sloping
gradients should be determined in the field by a "competent person" as defined by
OSHA. For preliminary planning, sloping of surficial soils at 1 to I (horizontal to
vertical) may be assumed. Excavations greater than 20 feet in height will require
an alternative sloping plan or shoring plan prepared by a California registered civil
engineer. Excavation safety is the responsibility of the contractor.
We anticipate that oversize material may be generated during demolition of
existing improvements, excavation within the Lusardi Formation, and grading
operations within uncontrolled (nonstructural fill areas). Recommendations for
treatment of oversize material are included in the attached General Earthwork and
Grading Specifications for Rough Grading (Appendix E). Excavated materials
with oversize boulders derived from the Lusardi Formation would necessitate
selective grading measures. In general, oversize material may be utilized in
approved surface applications or hauled off site.
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 at least 2 percent above
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 01557). The
optimum lift thickness required to produce a uniformly compacted fill will depend
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on the type and size of compaction equipment used. In general, fill should be
placed in lifts not exceeding 8 inches in thickness. The onsite soils typically
possesses a moisture content below optimum and may require moisture
conditioning prior to use as compacted fill. Localized areas of overly wet material
should be anticipated in previously landscaped areas or within clayey colluvial
soils. In general, overly wet material should be dried back and/or replaced with
granular import soils.
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 E.
6.1.5 Transition Mitigation
We anticipate that a transition from cut to fill may be developed beneath the
proposed classroom/shoot range building and the Fire Administration building. In
order to reduce the potential for differential settlement, we recommend that the
entire cut portion of transition within the building pad areas be overexcavated to a
minimum depth of 2 feet below the lowest proposed footing elevation and
replaced with properly compacted fill of very low to low expansion potential. The
overexcavation and recompaction should laterally extend a minimum of 5 feet
beyond the building perimeter. The base of the overexcavated portion of the
building pad should slope at approximately 2 percent toward the fill side to
mitigate the potential for accumulation that may result from surface infiltration.
Similar treatment should be anticipated for proposed buildings that overlie
backfilled cavities following demolition activities.
As an alternative to overexcavation beneath the building pad, all footings may be
extended a minimum depth of 12 inches into competent bedrock under the
observation of the geotechnical consultant.
6.1.6 Expansive Soils and Selective Grading
The onsite soils are expected to have a low to very high expansion potential. If
expansive soils are utilized at grade, typical expansive soil-related distress (such
as cracked flatwork and stucco, poor vegetation growth, etc.) may be expected
over the life of the project. Accordingly, we recommend that high or very high
expansive soils encountered during grading operations be placed in fill areas
below a minimum depth of 5 feet measured from the finish grade of the proposed
building pads and 3 feet in drive/parking areas, streets, and hardscape and not
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within 15 feet of the face of any slope. Expansive soils exposed at finish pad
elevations should likewise be removed to a depth of 5 feet and replaced with low
expansion potential compacted fill unless special foundation design
recommendations for expansive soil are implemented.
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 Jess than 50 per ASTM Test
Method 04829 (i.e. a very low to low expansion potential). 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 proposed structure should have an
appropriate drainage system to collect roof runoff. Positive surface drainage should be
provided to direct surface water away from the structure toward the street or suitable
drainage facilities. Planters should be designed with provisions for drainage to the storm
drain. Ponding of water should be avoided adjacent to the structure.
Regarding Low Impact Development (LID) measures, we are of the opinion that bioswales,
infiltration basins, and other onsite retention and infiltration systems can potentially create
adverse perched ground water conditions both on-site and off-site. In particular, this site is
underlain by Lusardi Formation that is known to contain both permeable and impermeable
layers which can transmit and perch ground water in unpredictable ways. Therefore, given
the site geologic conditions and project type, some LID measures may not be appropriate for
this site and project.
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.
Additional expansion testing should be performed as part of the fine grading operations.
If highly expansive soils are enc9untered and selective grading cannot be accomplished,
additional foundation design may be necessary.
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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 maximum allowable bearing pressure of 2,500 pounds pounds
square foot (psf) if founded entirely in properly compacted fill soils. An
allowable capacity increase of 250 psf for every 6 inches of additional width
and embedment depth may be used, not exceeding 3,500 psf. Where all
building foundations are extended to competent bedrock, an allowable bearing
pressure of 4,000 psf may be used. The bearing pressure for site walls 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 H/2, where H is
the slope height (in feet). The setback should not be less than 10 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.
6.3.2 Slabs
In general, slab-on-grade floors (excluding those subjected to heavy 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 be required. In addition,
interior slab-on-grade floors for the training tower and burn props structures may
be subjected to a variety of unknown loading and environmental conditions, such
as, heat and potentially chemicals that need to be evaluated by designers.
Slabs should also have crack joints at spacings designed by the structural
engineer. Columns should be structurally isolated from slabs. We emphasize
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that it is the responsibility of the contractor to ensure that the slab
reinforcement is placed at slab mid-height.
Interior floor slabs should be underlain by a 2-inch layer of clean sand (sand
equivalent greater than 30), underlain by a 10-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. 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 1/2 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 1/2 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.
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Lateral Pressures
Lateral loads may be resisted by assuming a passive pressure of 300 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.
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 very low to low expansion potential
(Expansion Index less than 50 per ASTM Test Method 4829) is shown on
below.
Table 3
Static Equivalent Fluid Weight (pet)
Condition Level 2:1 Slope
Active 40 60
At-Rest 55 75
Passive 300
(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 shown on Figure
5. 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
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compaction (based on ASTM Test Method Dl557) 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 (Mf) is smaller than 0.04, a factor of safety of 2.5
should be used for the passive resistance. The upper I foot of passive resistance
should be neglected unless the soil is confined by pavement or slab.
Preliminary pavement Design
The appropriate pavement section will depend on the type of subgrade soil, shear strength,
traffic load, and planned pavement life. Since an evaluation of the actual subgrade soils
cannot be made at this time, we have used an R-value of 5 and Traffic Indices (TI) of 5, 6,
and 7. The range of pavement sections presented on Table 4 is to be used for preliminary
planning purposes only. Final pavement designs should be completed in accordance with
the City of Carlsbad design criteria after R-value tests have been performed on actual
subgrade materials.
Table4
Preliminary Asphalt Pavement Designs
Traffic Index Preliminary Pavement Section
5 3 inches AC over I 0 inches Class 2 Aggregate Base
6 4 inches AC over 12 inches Class 2 Aggregate Base
7 4 inches AC over 16 inches Class 2 Aggregate Base
Asphalt Concrete (AC) and Class 2 aggregate base should conform to and be placed in
accordance with the latest revision of California Department of Transportation Standard
Specifications. Prior to placing the pavement section, the subgrade soils should have a
relative compaction of at least 95 percent to a minimum depth of 12 inches (based on
ASTM Test Method D 1557). Aggregate Base should be compacted to a minimum of 95
percent relative compaction (based on ASTM Test Method Dl557) prior to placement of
the AC.
Concrete pavement areas subjected to fire truck traffic loading and heavy concentrated
loads, such as, the areas surrounding the training tower and burn prop structures, require
special consideration. We recommend a minimum section of 8 inches of Portland cement
concrete (PCC) over 4 inches of Class 2 aggregate base. The PCC pavement section should
be provided with appropriate crack-control joints as designed by the project structural
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engineer. If sawcuts are used, they should be a minimum depth of Y. the slab thickness and
made within 8 hours of concrete placement. We recommend that PCC pavement utilize a
concrete mix design with a minimum 28-day strength of 3,250 psi. The upper 12 inches of
subgrade soils should be compacted to at least 95 percent relative compaction based on
ASTM Test Method 01557 prior to placement of aggregate base. The aggregate base layer
should be compacted to at least 95 percent relative compaction as determined by ASTM
Test Method 01557.
PCC and Class 2 base 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.
Construction Observation and Testing and Plan Review
The geotechnical consultant should perform construction observation and testing during
the fine, and post grading operations, future excavations and foundation or retaining wall
construction at the site. Additionally, footing excavations should be observed and
moisture determination tests of the slab subgrade soils should be performed by the
geotechnical consultant prior to the pouring of concrete. Foundation design plans should
also be reviewed by the geotechnical consultant prior to excavations.
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7.0 LIMITATIONS
The conclusions and recommendations presented 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 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.
-27-Leighton
~
N
~
0 60 120
F'EET
LY.I01 ~. Y:LC.'ALN
"'RffS TJ 'fll ~ N
PlP. 'I I R ----.... s::c.R rv
M 1/ I N:l
, __ .
Cr;
S:CJFITY CA IT
Of~ o~J W.AY
Of?!OlV WA v
I
........ __
Afn
®
Ill~ { 0/J<II
G~OUIOS
Afn (I' T
I
~POit1.141. PlJLC
AIH MH/WM
()I>JQRI,. \I ~
LEGEND
B-9 0
Afn•5' TDa5'
APPROXIMATE BORING LOCATION,
DEPTH OF FILL (IN FEET), TOTAL DEPTH
OF BORING (IN FEET)
ARTIFICIAL FILL NON-STRLICTLIRAL (GEOCON, 1985) Afn
Kl
1UNE a1
LUSARDI FORMATION, (CIRCLED WHERE BLIRED)
~.OA PACK NG
~IAL-
r ~[ AOI't• S"'RA TIC\ f",,:. ""'V
T-4
1%1
APPROXIMATE LOCATION OF SEISMIC LINES
(LEIGHTON, 2001)
APPROXIMATE LOCATION OF TRENCH
EXPLDRA TION (LEIGHTON, 2001)
CARLSBAD FIRST RESPONDER'S JOINT-USE
TRAINING FACILITY
CITY OF CALIFORNIA
Scale: 1""30'
Dnltlod By: MAM
FIGURE2
Date: 7/08
CPBy:BOT
CONCEPTUAL SITE PLAN
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602256-001
APPENDIX A
REFERENCES
Bartlett, S.F. and Youd, T.L., 1995, Empirical Prediction of Liquefaction-Induced Lateral
Spread, Journal of Geotechnical Engineering, Vol. 121, No.4, April1995.
Blake, 2000, EQFAULT, Version 3.0.
California Geologic Survey (COS), 2003), Probabilistic Seismic Hazard Analysis Map, June
2003.
California Building Standards Commission (CBSC), 2007, California Building Code (CBC).
Geocon, Inc., 1982, Soil Investigation and Geologic Reconnaissance for Civic Operations Center,
Carlsbad, California, File No. P-2751-J01, dated June 14, 1982.
1984, Updated Geotechnical Investigation for City of Carlsbad Safety Center,
Carlsbad, California, File No. D-2751-J02, dated September 12, 1984.
----, 1985, Final Report of Testing and Observation Services During Mass Grading
Operations for Carlsbad Safety Center, Carlsbad, California, File No. D-2751-J03,
dated June 17, 1985.
Hart, 1997, Fault Rupture Hazard Zones in California, Alquist-Priolo Special Studies Zones Act
of 1972 with Index to Special Study Zone Maps, Department of Conservation,
Division of Mines and Geology, Special Publication 42, revised 1997.
Hannan, D., 1975, Faulting in tbe Oceanside, Carlsbad and Vista Areas, Northern San Diego
County, California in Ross, A. and Dowlens, R.J., eds., Studies on tbe Geology of
Camp Pendleton and Western San Diego County, California: San Diego Association
of Geologists, pp. 56-59.
Ishihara, K., and Yoshimine, M., 1992, Evaluation of Settlements in Sand Deposits Following
Liquefaction during Earthquakes, Soils and Foundations, Vol. 32, No. 1, pp: 173-
188.
Leighton and Associates, Inc., 1988, As-Graded Report of Rough Grading Operations, City of
Carlsbad Fire Station No. 5, Carlsbad Safety Center, Carlsbad, California, Project
No. 8871838-04, dated September 8, 1988.
A-1
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602256-001
APPENDIX A (Continued)
----, 2001, Update Geotechnical Investigation, Proposed Carlsbad Public Works Center
Facility Expansion, Orion Way and Orion Street, Carlsbad, California, Project No.
040448-001, dated September 4, 2001.
RRM Design Group, 2008, Conceptual Site Development Plan, Joint First Responders Training
Facility, dated May 2008.
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 Bartlett, 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.
A-2
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GEOTECHNICAL BORING LOG KEY
Date -----,-----,----
Project KEY TO BORING LOG GRAPHICS
Drilling Co.
Hole Diameter
Elevation Top of Elevation '
c: u "' 0 ~-:Ea "' ·--"t1 -.. -., .... c.., c.o :I ~11. "u. f!..J "" Q -iii C) :(
N !
__ -
ci z
"' c. E ~
Drive Weight
Location
~ "iii "-O>U QQ.
~ Q
G) ';fl. .. -,--" "'"' ·--oc: :;;o
()
ui"'":' ~~ (3<-!
_II)
Sheet 1 of
Project No.
Type of Rig
DESCRIPTION
"o::i Logged By ____________ _ If)-
Sampled By
Asphaltic concrete
Portland cement concrete
; gravelly clay; sandy clay;
UL
ML ·; silt; clayey silt w1th low" .. ,
MH ; silt; ; fine sandy or silty soils; elastic silt
Drop_·_·
--IML-LL Clayey silt to' .. , .. ,
~~~~-t--Jt--t--[-iGWuwtw~~lgra~vel;~~~~~·xru ~re •. ~little:OrOOorno>~fines-----1
\~' UY r~uy "'~oct gravel; I ~xrure, little or no fines
UC Clayey gravel; ' ~xture
'w I sand; gravelly sand, · > fines
... 'Y Poorly graded sand; gravelly sand, little or no fines
'M Silty sand; poorly graded sand-silt ~xrure
-~~_,---H--+--r~--r--sM= __ k __________________ ~
-
-
20-
-
-
25-
-
-
SAMPLE TYPES:
5 SPUTSPOON
R RING SAMPLE
B BULKSAMPLE
T TUBE SAMPLE
B-1
C-1
G-1
R-1
SH-1
S-1
G GRAB SAMPLE
SH SHELBY TUBE
Ground water encountered at time of drilling
Bulk Sample
Core Sample
Grab Sample
Modified California Sampler (3" O.D., 2.5 l.D.)
Shelby Tube Sampler (3" O.D.)
Standard Penetration Test SPT (Sampler (2" O.D., 1.4" J.D.)
TYPE OF TESTS:
OS DIRECT SHEAR
MD MAXIMUM DENSITY
CN CONSOUDATION
SA SIEVEANALYSIS
AT ATTERBURG UMITS
El EXPANSION INDEX
RV HC
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GEOTECHNICAL BORING LOG 8-1
Date 6-30-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
Sheet 1
Project No.
Type of Rig
of _1_
602256-001
CME-75
Hole Diameter ="8'-'in".'-:---==:--
Eievation Top of Elevation 355'
Drive Weight 140 pound hammer Drop 30"
355·
350· ~
1·.
-L· _r.·
-L·.
-I:
-.· .-.·.
-....
-.... . . . -....
345 11 _;·-t'fj:
-
-
-
340· 15-
-
-
-
335· 20-
-
-
-
-
330 25-
-
-
-
-
325
SAIIPlE TYPES:
S SPLIT SPOON
R RING SAMPLE
B BULK SAMPLE
T TUBE SAMPLE
., ., , .a i! <
Location See Geotechnical Map
>. 0 --z ~8 'iii
Q) c-G>U c. OIL Cr:>. ma; E >. .. D.. ~ Ill c
B-1
0'-5'
R-1 50/6" 107.7
R-2 5014"
G GRAB SAMPLE
SH SHELBY TUBE
t»~ ~..; .ac .,., ---oc ::!!0 (J
9.1
ui""':" UIU) ... -(J (J . -111 '6::i Ill-
~JVJ
SP
SM
DESCRIPTION
Logged By BP
Sampled By BP
.31ll\'Jtl'fL FILL @ 0'-2': Fme to medtum grained silty SAND: Dark brown, moist
@ 2': Light brown, damp
1------------------------------LUSARDI FORMATION
@ 5': Fine to coarse grained SAND: Orangish brown, damp, Vel)'
dense, cemented conglomerate, slightly undisturbed
TYPE OF TESTS:
OS DIRECT SHEAR
MD MAXIMUM DENSITY
CN CONSOUDATION
CR
HC HYDRAUUC CONDUCTIVITY
AT ATTERBURG UMITS
El EXPANSION INDEX
RV D.VAO ""
LEIGI1 IUN
., -.,
Q) 1--0 .,
g;
1-
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GEOTECHNICAL BORING LOG B-2
Date 6-30-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
Sheet 1
Project No.
Type of Rig
of _1_
602256-001
CME-75
Hole Diameter --=8'-'i,_,_n.'-----
Eievatlon Top of Elevation 355'
Drive Weight
Location
140 pound hammer Drop 30"
See Geotechnical Map
>-.. ci Q)'f!. 0-:-DESCRIPTION -$-., --., u "' z ~8 'iii .. ..,. tn(l) "' :6-:Ecn , "' c-.E!c ... 1-.... ... .. CI>U -o -o.o .a ii OIL "'"' o. ~"' .... I!..J co. ·--_(I) 0 CI>LL eLL i3 E ma oc C) >-::;;o '0:::) Logged By BP "' jjj <( .. D.. .. g; (I) c 0 en-
N s Sampled By BP 1-
355 ,. >M Grass surface
ARTIFICIAL FILL @ 0': Fme to m&lnun grained silty SAND: Light brown, moist
-
-~-.
-B-1 1-----------------------------LUSARDI FORMATION
350· 5-0'-5'
100.7 10.8 @ 5': Fine to coarse grained silty SAND: Light brown to orangish R-1 50/4" brown, moist, very dense, conglomerate, slightly disturbed -
-
-
;345 IU-@ 10': Damp, little recovery R-2 50/4" -
I' -
-
-
340 1<-I.-. ~-.
l· I: R-3 50/3" @ 15': Little recovery
-~..t B-2 ~-. 15'
-l-
-I ;
I --~--I-\ (a) 19': Hard drillinR, refusal
335 20-Total Depth= 19 Feet
No r;.und water encountered at time of drilling
-Bac Ill on 6130/08
-
-
330-25-
-
-
-
-
SAMPLE TYPES: TYPE OF TESTS: ., s SPLIT SPOON G GRAB SAMPLE OS DIRECT SHEAR HC HYDRAULIC CONDUCTIVITY
R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT AnERBURG LIMITS
B BULK SAMPLE CN CONSOLIDATION El EXPANSION INDEX
T •~ CR RV D_,,., ...
LEIGI11UN
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GEOTECHNICAL BORING LOG B-3
Date 6-30-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
Sheet 1
Project No.
Type of Rig
of 1
602256-001
CME-75
Hole Diameter ---"8-"in'-".'-------
Eievatlon Top of Elevation 366'
Drive Weight
Location
140 pound hammer Drop 30"
See Geotechnical Map
ci ... m"ift. cri""':" DESCRIPTION J!l c: .. --.. 0 ~ ., z ~g 'iii ....... Ultfl ., ,.,-:6-.C:CJ '0 Cl) c: .... .ac: ... 1-.... ... .. a.o .a G>U -u .... a. ""' .... u. >"' ., .. ~ .... ca. ·--_Ul 0 .,u.. c"-j3 E iiit oc: jjj (!I ... ::;;o '6::i Logged By BP Cl) c( .. D.. ... ~ Ul 0 u tn-
N s Sampled By BP 1-
r·. 'M Grass surface
365 -L·. ARTIF1CIAL FILL t:' @ 0': Fme to medmm ftained sil¥ SAND: Dark brown, moist, some -r:: f':. rock/cobblesldifficu t drilling to 4 feet
-L· r:: -r:: 1··-f'~
5-L·. r< B-1 50/4" @ 5': No sample recovery CR
360 -r:: f'~ 0'-5'
+ r:: J: 1':
-L· t :· to-r:: f'~ ~@~: : to ')'e<)ium grained silty SAND: Dark brown, mois~ very
355 L·. R-1 50/1"
r:: t:: ----------------~
-r ·.
-~: r ...
r:: t-: -r ._ ... L· r:: _1:·_ R-2 50/5" @ 15': Fine to coarse grained silty SAND with cobbles and ~ve~ up
350 f'~ B-2 to 1/2 inches in diaroeter, su~ar, light brown to orgarush 15'
_L·. r<
brown, darop, very dense, dis
r:: f'~ -difficult drilling at 17 to 18 feet
-
L·. r_.--r:: t-:
.... R-3 70/6" SP @ 20': Fine to coarse grained SAND: Light brown to orangish brown,
345 -.... dam\j very dejritl cemented conglomerate @ 21 ': ifficult dril ing
\Refusal at 22 feet I
-Total Depth-22 feet
No r;.und water encountered at time of drilling
--Bac llled on 6/30/08
25-
340 -
-
-
-
SAMPLE TYPES: TYPE OF TESTS: fl s SPLIT SPOON G GRAB SAMPLE OS DIRECT SHEAR HC HYDRAULIC CONDUCTIVITY
R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSilY AT ATIERBURG LIMITS
B BULK SAMPLE -~ CONSOLIDATION El EXPANSION INDEX
T TUBE SAMPLE RV R·VALUE
LEiGHTON
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GEOTECHNICAL BORING LOG B-4
Date 6-30-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavatio
Sheet 1
Project No.
Type of Rig
of 1
602256-001
CME-75
Hole Diameter ...-::B..::incc·-,----
Eievation Top of Elevation 364'
Drive Weight
Location
140 pound hammer Drop 30"
See Geotechnical Map
0 ,., (JJ~ cri-:-DESCRIPTION .'!! c: ., --.,
0 -~ ., z ;g "iii ~,.;-UIVI ., ,.,.-=-.COl .., ., c: ... .ilc: ... 1-ca"' a."' a.o .a "'"' -o .... c. ou-.,., 0->"' .,., I!...J ca. ----VI 0 G>LL eLL l3 E iiit Oc: (.!) ,., :;;o "6::i Logged By BP .,
iii < .. D.. ~ g; VI c 0 VI-
N s Sampled By BP 1-
v >M ~s surt~L FILL
-L·. f!1J u': rme 10 memum grained silty SAND: Dark brown, moist -r::
-.·. @ 3': Fine to medium grained silty SAND: Light brown, damp with
360· -B-1 cobbles, up to 1/2 inches in diameter, subarigular
s-r .. 0'-5'
@ 5': No recovery, lst resample, rock in shoe, 2nd time, no sample, DS 3rd ~ recovery -~---R-1 39 130.4 10.0 Fine to coarse grained silty SAND: Dark brown to reddish brown,
-L·. damp, medium dense
J:
355· -~: r.' ... -~ ·~~nN _________________
R-2 50/3" SP :IV: rme.to coo,rse ~ S~: Light browo to organish brown, -. . . . dainp, very dense
-. . . .
-· . . .
350 -.. ..
15-1· . . . B-2 50/2" @ 15': No recovery .. _I· . 15
I· .. -... I· . . .
-1-. . .
345 -.. I· .. .. 1··. r-. B-3 50/2" SM @ 20': Fine to medium ~ned silty SAND: Brown, damp, very dense, 20 from shoe and distur sample -L· r:: -I:·_ f"~ -
340· -
25-R-3 50/4" 106.1 8.7 @ 25': Fine to coarse grained silty SAND: Light browo to reddish
-brown with cobbles up to 1/2 mches in diameter, subangular, cemented conglomerate
-
• (a) 28': Hard I refusal, no sample recovery
335· -~;:~ ~28Feet
11n~~/AA , •u at time of drilling
SAMPLE TYPES: TYPE OF TESTS: ~ s SPUTSPOON G GRAB SAMPLE OS DIRECT SHEAR HC HYDRAUUC CONDUCTIVITY
R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT AnERBURG UMITS
B BULK SAMPLE CN CONSOUDATION El EXPANSION INDEX
T ,. CR RV R-VALUE
LEIGI-!1\.JN
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GEOTECHNICAL BORING LOG 8-5
Date 7-1-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
Sheet 1
Project No.
Type of Rig
of 1
602256-001
CME-75
Hole Diameter ="8'-'in'-'.'::---::=:--
Eievatlon Top of Elevation 356'
Drive Weight
Location
140 pound hammer Drop 30"
See Geotechnical Map
ci >. 0)~ ui-:-DESCRIPTION s c "' --"' o_ " Cl) z ~g u; ~.r "'Ill Cl) =-:Ecn ., Cl) c-.ilc ... 1-,.,., c."' c.o .a "'" -o -!l!m c. OU-.. ., 0-.,., f!..J cc. ---_en 0 ..... c"" il E -~ oc C) m., >. a:; Logged By BP CD iii c( .. D.. ~ :::!!0 g; en c 0 en-
N s Sampled By BP 1-
1-~ >M Grass surface ' FILL
355 -L-(!!) u·: Fme 10 meonun grained silty SAND: Dark brown, moist _,.
-
--f"TiS, ·~-7.~ ON ----------------
s-r, R-1 50/4'' 103.4 6.0 @ 5': Fine to coarse grained silty SAND: Light brown to organish
350 -':· ~:. B-1 brown, damp, very dense conglomerate 0'~5'
-
-
-
to-!:·
R-2 50/6" @ 10': Disturbed sample
345· -.·.
-
-
-
15-:",
R-3 50/1" @ 15': No recovery
340· -
-
-
-
20-R-4 50/5" @ 20': Difficult drilling, disrurbed sample
335· -
-
-
, Refu<al at 24 feet r
25-Total Depth= 24 feet below ground surface
No T:fiund water encountered at time of drilling
330· Bac 1lled with bentonite on 7/1/08
-
-
SAMPLE TYPES: TYPE OF TESTS: ,. s SPUTSPOON G GRAB SAMPLE OS DIRECT SHEAR HC HYDRAUliC CONDUCTIVITY
R RING $AMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS
~~~~ ~~ CONSOLIDATION El EXPANSION INDEX
RV R-VALUE
LEIG "ON
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GEOTECHNICAL BORING LOG B-6
Date 7-1-08
Project Carlsbad/JFRTF
Drilling Co-Baja Excavation
Hole Diameter -:-=8-'incc·-,------.,.--
Eievation Top of Elevation 351'
Drive Weight
Location
c ~ .... " =-:EQ .... c."' c.o >"' .,., I!-' .,LL eLL C) iii
S.AMPLE TYPES:
S SPLIT SPOON
R RING SAMPLE
B BULK SAMPLE
., ., , .a i3 <C
0 ~ .,.,. -z ~g "iii ......... ., o::-.ao:: "'" ii 01'-.,., cc. ·--E ffit ... 01: .. D.. .... :;;o
Vl c u
R-1
B-1
0'-5'
42 110.0 11.7
R-2 50/2"
R-3 50/1"
5011"
G GRAB SAMPLE
SH SHELBY TUBE
Sheet 1
Project No.
Type of Rig
of 1
602256-001
CME-75
140 pound hammer Drop 30"
tri"'":' U>tn ... -u u . _tn
"i5::i tn-
See Geotechnical Map
DESCRIPTION
Logged By BP
Sampled By BP
grained silty SAND: Dark brown, wet, medium
@ 7': Change to light brown, moist, in cuttings
silty SAND: Light brown to organish
@ 15': Conglomerate, disturbed
@ 25': Fine to ooarse grained silty SAND: Light brown to organish very dense, i:lamp, conglomerate, small amount of sample
TYPE OF TESTS:
OS DIRECT SHEAR
MD MAXIMUM DENSITY
CN CONSOUDATION
CORROSION
HC HYDRAULIC CONDUCTIVITY
AT ATTERBURG LIMITS
El EXPANSION INDEX
RV R-VALUE
J1l .,
~ -0 ., g;
1-
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Date 7-1-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
GEOTECHNICAL BORING LOG B-7
Sheet 1
Project No.
Type of Rig
of 1
602256-001
CME-75
Hole Diameter -=8'-'i,_,_n.'----~
Elevation Top of Elevation 352'
Drive Weight
Location
140 pound hammer Drop 30"
See Geotechnical Map
0 ::-G>rf!.. vi"'":" DESCRIPTION J!l
§ ., -., u .. z ~g 'iii .....; VIII) .. .,-=-:Ecn ... .. c-.ac ... 1-.... ... .. .a G>U -o -a.o ii oU-.... o . ,.., ., .. I!...J CCL ---_II) 0 ., .... cu. (!) ;! E m~ >-Oc 'o::i Logged By BP .,
iii <( .. D.. ... :;;o g; II) c 0 II)-
N 5 Sampled By BP 1-
0 .... ~M Grass surface
0 0 ... ARTIF1CIAL FILL -0 0 0 @ 0': Fme to medmm silty SAND: Medium brown, damp to moist ....
•• 0 350 -:: : •• 0 ...
-0 0 ... 0 0
0 0 0
-:· 0 •• 0 B·l 0 0 ... 0'~5'
5-·.:. 0 0 @ 5': Fine to coarse silty SAND: Dark reddish brown, moist, medium •• 0
-:· 0 •• 0 R-1 36 122.6 10.5 dense
0 0
0 ...
345 -·.:. 0 0 @ 7': Cuttings change to light brown 0 0 0
-:·. 0
•• 0
0 0 ... -·. :. 0 0
•• 0
10-:· 0 •• 0 -----------------------------0 0
0 0 0 •• R-2 50/3" LUSARDIFORNUUTON
0 0 0 @ 10': hne to coorse gpllnixl silty SAND: Light brown to orangish . : ~ .. 0 brown, damp, very Oense, conglomerate ..... J40 -·. . ..
-'::"· 0 0
0 0 0 ..... 0
-0 0 0
0 0 ...
15-'::"· •• 0 @ 15': Light brown. organish brown to dark brown •• 0 •• R-3 50/6" -0 0 0 0 0 ...
0
335 -.... 0 0 0 0 .....
-0 0 ...
-... 0 0
0 0 0 0 0
•• 0 •• 0
20-0 0 ... @ 20': Fine to coarse silty SAND: Light brown to organish brown, 0 0 R-4 50/2"
-::0 •• 0 B·2 damp, very dense, conglomerate
•• 0 •• 0 20'
330 -0 0 ...
0 .... '@ 23': Refusal, difficult drilling
-Total Depth~ 23 Feet
No r;.und water encountered at time of drilling
25-Rae died with bentonite on 7/1/08
-
325 -
-
-
30
SAMPLE TYP~S: TYPE OF TESTS: .cf s SPLIT SPOON G GRAB SAMPLE DS DIR~CT SHEAR HC HYDRAULIC CONDUCTIVITY
R RING SAMPLE SH SHELBY TUBE MO MAXIMUM DENSITY AT A.TTERBURG UMITS
B BULK SAMPlE CN CONSOLIDATION El EXPANSION IND~
T TUBE SAMPLE CR CORROSION RV R·VALUE
LEIGHTON
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GEOTECHNICAL BORING LOG B-8
oate 7-1-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
Sheet 1
Project No.
Type of Rig
of 2
602256-001
CME-75
Hole Diameter 8 in -Drive Weight 140 pound hammer Drop 30"
Elevation Top of Elevation 354' Location See Geotechnical Map
0 ~ .. ~ cri-:-DESCRIPTION J!l
<: u "' -'iii ..
~-=-Cl) z ~g ....... UIUJ Cl)
.&:C) .., Cl) "'"" .a~: ... 1-.... a."' a.o .a G>U -o .... 'ii OIL .!!.! 0->"' .,., f!..J ca. -UI 0 CllLL eLL (!) il ~ m:u > 0<: 'iS::i Logged By BP Cl) iii <( II.. ... :;;o g; Ul c 0 rn-
t. s Sampled By BP 1-
1·. 'M ~sat sur!~ F1LL -L·. ® u· tme to memum grained silty SAND: Dark brown, moist
-::· @ 2': Light brown, damp
--urornn~nffiunn~-----------------
350· -I ; B-1
5-0'-5'
@ 5': Fine to medium grained silty SAND: Light brown, damp, very _r:: R-1 50/5" dense
-
-
345 T lo-1:· @ 10': Fine to coarse grained silty SAND: Liebl brown to orangish _L· R-2 50/5" brown, damp, very dense, conglomerate, disturbed, shoe sample on
-':: top
_L·.
340 r:: -
,_L·. r:: R-3 50/3'' @ 15': Fine to medium grained silty SAND: Light brown to organish
-brown, damp, very dense, less coarse tban previous
-L· r:: -
335 -
20-L-. R-4 50/4" @ 20': Cemented
-r::
-L·. _[:
i':
330 -L-
25-r:: R-5 50/3" @ 25': Rock in sample 1--.
-L-. B-2
25' -r::
-L-
325· + f'~
SAMI'LE TYPES: TYPE OF TESTS:
"
s SPUTSPOON G GRAB SAMPLE OS DIRECT SHEAR HC HYDRAUUC CONDUCTIVITY
R RING SAMPLE SH SHELBY TUBE MD MAXIMUM DENSITY AT ATTERBURG LIMITS
B BULK SAMPLE CN CONSOUDATION El EXPANSION INDEX
T TuaE SAMPLE CR RV D.VAO ""
LEIGI iON
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GEOTECHNICAL BORING LOG B-8
Date 7-1-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
Hole Diameter c:-=8'-'in"'.~--
Eievation Top of Elevation 354'
Drive Weight
Location
0 ~ Q)';!. 1: "' -~-u ., z ~g 'iii ~...,. =-:Ec:n , ., "'"" .a~: .... ..... c.o .a c. ()II. GIU .,., >., ., .. ~...J ca. ·--GILL eLL i3 E iii~ 01: iii (!) ... ::;;o <( .. 11. ~ rn c 0
N s
r •• R-6 50/4" -:: r· :· -':: ~-~
-_.
r:: 320· -·:: I'~
35-:: r-:· -':: ~-~
-,~
-·:: t::
r ·.
315· -. -·; r: :·
5010"
-
-
-
310· -
45-
-
-
-
305· -
50-
-
-
-
300· -
55-
-
-
-
295· -
SAMPLE TYPES:
s SPliT SPOON G GRAB SAMPLE
R RING SAMPLE SH SHELBY TUBE
8 BULK SAMPLE
T TUBE SAMPLE
140 pound hammer
See Geotechnical Map
Sheet 2
Project No.
Type of Rig
cri-: DESCRIPTION II) II) ... -o o. _rn 'o::i rn-Logged By BP
Sampled By BP
SM ({9 ~~~;:d!;,~;~ =ed >iuy OMU Dark
@ 35': No sample, drilled to 40 feet
@38': Difficult drilling
"· • refusal
Total Depth-40 Feet
No ifiund water encountered at time of drilling
Bac died with bentonite on 7/1/08
TYPE OF TESTS:
OS DIRECT SHEAR HC HYDRAULIC CONDUCTIVITY
MD MAXIMUM DENSITY AT ATTERBURG LIMITS
CN CONSOLIDATION B EXPANSION INDEX
CR CORROSION RV D.V4111F
LEIGn1UN
of 2
602256-001
CME-75
Drop 30"
"' -"' .,
1-... 0 ., g;
1-
··c·
r
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GEOTECHNICAL BORING LOG B-9
Date 7-1-08
Project Carlsbad/JFRTF
Drilling Co. Baja Excavation
Hole Diameter ---"8-'in'". ___ _
Elevation Top of Elevation 352'
0 c ., -~-u "' z ~8 :6-:Ec:n .., "' .. ., .._., c.o .a c. Qll. >"' .,., E--' .,u.. c"-'E E -..
Cl m., iii ~ .. D.. II)
Drive Weight
Location
~ GJ'ffl. "iii '-,.; c ... .ilc CI>U .,., QQ. ---oc » .. ;:eo c 0
R-1 50/6" 104.4 7.9
SAMI'LE TYPES:
S SPLIT SPOON
R RING SAMPLE
B BULK SAMPLE
B-1
0'-5'
G GRAB SAMPLE
SH SHELBY TUBE
140 pound hammer
Sheet 1
Project No.
Type of Rig
See Geotechnical Map
0-:-DESCRIPTION 11>11) ... -o 0-_II) ·cs::i
II)-Logged By BP
Sampled By BP
of 1
602256-001
CME-75
Drop 30"
., -.,
{! ... 0
"' S!;
1-
to organish HC
water encountered at time of drilling with bentonite on 711108
TYPE OF TESTS:
DIRECT SHEAR
MAXIMUM DENSITY
CONSOLIOAliON
HC HYDRAULIC CONDUCTIVITY
AT ATTERBURG UMITS
El EXPANSION INDEX
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Exploration Trenches Logs for T -3 an T -4
(Leighton, 2001)
-------------------
LOG OF TRENCH: .,._,
Project Name: OillisiCadshad ~c Logged by: sw
ENGJNEERJNG PROPERTIES
Project Number: 040448-001 Elevation: '""'
Equipment: C ll :I 31 OE Backhoe Location/Grid: ~~~ 1 u.-
GEOLOGIC DATE: 5125101 DESCRIPTION: GEOWGIC Sample Moisture Density
ATTITUDES UNIT uses No. (%) (pcf).
ARTIFICIAL FILL-nonstructuml Afu 3
@7-8'
A @ 0'-4.5': Clayey silty medium to coarse SAND with few fine gravels, SM-
cobbles and boulders: light to dark brown and gray, moist, medium dense sc
TOPSOILICOLL~ Topsoil/
Qcol
B @ 4.5' -6': SAND/SILT: dark gray-brown, moist, loose; with scattered SMJ
organic debris (odor) and few rounded gravel ML
c @ 6'-6.3': Silty SAND: chocolate brown, moist, loose; few organic SM
debris; micaceous
@ 6.3'-7': Sandy CLAY: gray/brown, moist, firm to stiff sc
LUSARDI FORMATION
Kl
E @ 7'-8': Medium to coarse SANDSTONE CONGLOMERATE, weathered GP
granitic gravel, cobbles and boulders in a medium to coarse sandstone matrix: llsht brown, 1m1v-brown and brown, oranRC!red, damP, verv dense
GRAPIDCAL REPRESENTATION: SCALE: 1"=5' SURF ACE SLOPE: 5° to E TREND:N2SW
_·.--. . ----~ :__:. --.·-· · . .:. v -----. . II ~ ·--. . ' . ., ·<J 4 -. ::-:------_A ___ __ .....;.._ __ .
C> ~--· ·----~ _,-~ . ~ ~ . -.
-... .. -----\•:-----::'--0 ~--<::l· .-'o · .... .. --=-. ..::... -·-· I--;-;-.. ;.. .
"'~~~ .. ---. ... -·:--~;,... . . -• 0.
'-.· . . --ID ·-o --··~
D # • • • .. ....... c Total Depth = 8 Feet
~--cE ·. ;.,o-_y No Ground Water Encountered
Backfilled: smto 1
(uncompacted)
-------------------
Project Name: __ .J.GJJiJJIIlliis/~UC...JaiiTIIliSbllJa~duP~W.:u..C.~---Logged by: __ ,iUL<::w ________ _
Project Number: _.J:OI!I4u04!1J4ll8i:J-OWO!JI ______ _ Elevation: ___ .l;>><;u.;_?'--------------1
Equipment:
GEOLOGIC
ATTITUDES
CAT 310p Backhoe Location/Grid: s,.. ( · .tu.
DATE: 5/25/01 DESCRIPTION:
ARTIFICIAL FILL-nonstructural
A @ 0'-2.5': Clayey silty medium to coarse SAND with scattered gravel and
cobble: brown to light gray-brown, moist, medium dense
TOPSOIUCOLLUVIUM
B @ 2.5'-3': Silty medium to coarse SAND: dark gray, damp, loose; scattered
organic debris (odors)
C @ 3'-4': Silty medium to coarse SAND: chocolate brown, damp, loose:
micaceous rare; organic debris
LUSARDI FORMATION
D @ 4'-5': Medium to coarse SANDSTONE CONGLOMERATE, weathered
granitic gravel, cobbles and boulders in a medium to coarse sandstone matrix:
fi!dtt brown, JUav-brown and brown, oraniZelred, damp, vel)' dense
GEOLOGIC
UNIT
Afn
TopsoiV
Qcol
Kl
GRAPIDCAL REPRESENTATION: SCALE: 1=2' SURFACE SLOPE: 0°
l-. ·-·-·
\
·.--·.-c. -r-··-st·-_, ··r: ...:_-;: -.. ·-.-··-···-r.-.•.-
\( ~_'-.,0·~~ }-·_o/ ~-·· .. ~
LOG OF TRENCH: T.A
ENGINEERING PROPERTIES
uses
SM-
sc
SM
SM
Gp
Sample Moisture Density
No. (%) (ocf).
4
4-5'
TREND:NIOE
Tolal Depth • 5 Feet
No Ground Water Encountered
Backfilled: 5125/0 I
(uncompacted)
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602256-001
APPENDIX C
Laboratory Testing Procedures and Test Results
. Direct Shear Test: A direct shear test was performed on a selected remolded sample which was
soaked for a minimwn of 24 hours under a surcharge equal to the applied normal force during
testing. After transfer ofthe 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
I hour prior to application of shearing force. The sample was tested under various normal loads
utilizing a motor-driven, strain-controlled, direct-shear testing apparatus at a strain rate of 0.05
inches per minute. After a shear strain of 0.2 inches, 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
considered to be ultimate values and are shown in parenthesis.
Sample Location Sample Description Test Type Friction Angle Apparent
(degrees) Cohesion (pst)
B-4,@ 0-5 Feet Brown Clayey to Silty Sand Remolded to 27 (27) 300 (150) 90%
Maxirnwn Densitv Tests: The maxirnwn dry density and optimwn moisture content of typical
materials were determined in accordance with ASTM Test Method Dl557. The results of these
tests are presented in the attached data.
Sample Location Sample Description
Maximum Dry Optimum Moisture
Density (pcf) Content(%)
Brown Clayey to Silty Sand
B-4, @ 0-5 Feet 131.0 8.0
(SC-SM)
Yellowish Brown Sand w/Clay
B-9,@ 0-5 Feet 133.5 7.5
(SP-SC)
C-1
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602256-DOl
APPENDIX C (Continued)
Minimum Resistivity and pH Tests: Minimum resistivity and pH tests were performed in general
accordance with Caltrans Test Method CT643 for Steel or CT532 for concrete and standard
geochemical methods. The results are presented in the table below:
Sample Location Sample Description pH
Minimum Resistivity
(ohms-em)
B-3 @ 0-5 Feet Brown Silty Sand (SM) 7.39 6,000
Chloride Content: Chloride content was tested in accordance with Caltrans Test Method CT422.
The results are presented below:
Sample Location Chloride Content, ppm Chloride Attack Potential*
B-3 @ 0-5 Feet 84 Threshold
*per City of San Diego Program Gmdelmes for Design Consultant, 1992.
Soluble Sulfates: The soluble sulfate contents of selected samples were determined by standard
geochemical methods (Caltrans Test Method CT417). The test results are presented in the table
below:
Sample Location Sample Description Sulfate Potential Degree of
. Content(%) Sulfate Attack*
B-3 @ 0-5 Feet Brown Silty Sand (SM) 0.018 Negligible
.. .. • Based on the 1997 edition of the Umfonn Buddmg Code, Table No. 19-A-4, prepared by the International
Conference of Building Officials (ICBO, 1997).
Moisture and Density Determination Tests: Moisture content and dry density determinations were
performed on relatively undisturbed samples obtained from the test borings. The results of these
tests are presented in the boring logs. Where applicable, only moisture content was determined
from "undisturbed" or disturbed samples.
C-2
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602256-001
APPENDIX C (Continued)
Hydraulic Conductivity (ASTM D5084): Hydraulic conductivity tests are performed on selected
undisturbed and remolded samples collected from the exploratory borings. These tests are
performed in general accordance with the ASTM Test Method DS084. The samples are placed in
the triaxial testing device and tested with a Falling Head Method. The table below reports the
average hydraulic conductivity values for the samples.
Sample Location
B-9, (remolded-90% RC) Sand w/clay(SP-SC)
C-3
Average Hydraulic Conductivity
(em/sec)
0.000021
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Seismic Refraction Survey
(Leighton, 2001)
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215 So. Highway 101. Suite 203 P.O. Box 1152 Solana Beach. CA 92075
Telephone: (658) 481-8949 Facsimile: (858) 481-8998 Website: subsurfacesurveys.com
August 29, 2001
Leighton and Associates
3934 Murphy Canyon Road, Suite B-205
San Diego, CA 92123
Project /Invoice Number: 01-335
Attn: Mike Jensen Re: Seismic Refraction Survey, Carlsbad, California
Introduction • This report presents the findings of a seismic refraction survey conducted over the
gravel lot on the northeast corner and the baseball diamond on the southeast comer of Orion Way
and Orion Street in Carlsbad, California (Fig. 1) on August 10111,2001. The purpose of this survey
was to evaluate the thickness of fill, alluvium/colluvium, and depth to bedrock.
Instrumentation and Field Procedure-A total of 18161ineal feet of data was collected along 8
survey lines. The seismic line locations were marked in the field with paint and were detailed on a
topographic map supplied by the clienfs representative (Fig. 2). The spread layouts were
determined at the site, and were critically located to maximize useable information.
Seismic waves were initiated at the ends of each spread by striking an aluminum plate with a
20-pound sledge (Fig 3). Seismic arrivals were detected by a series of twenty-four geophones,
and recorded with a Bison 9024 24 channel seismic system with DIFP, digital instantaneous
floating point, capability. This automatically sets gains, balances channels, and sets other
shooting parameters, in real time. The materials at the site provide good transmission of seismic
energy, and the records produced are of good quality.
Methodology -The refraction method uses first-arrival times of refracted seismic waves to
detennine the thicknesses and seismic velocities of subsurface materials. Seismic waves
generated at the surface are reflected and refracted from boundaries separating materials of
contrasting velocities, and are detected by a series of surface geophones. The travel times of the
seismic waves are used in conjunction with the shot-geophone distances to obtain thickness and
velocity information, in this case geophone spacing varied between five, ten, and twelve feet (line
length depended on aocess and desired coverage) and shot points were conducted at either five or
ten feet off each end of the line and between geophones 6 and 7, 12 and 13, and 18 and 19. The
line lengths varied between 120 and 276 feet in length and allowed for an approximate depth of
investigation of approximately one third of the overall line length.
------------------
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The seismic refraction technique requires that velocities increase with depth, which is usually the
case. A layer having a velocity lower than that of the layer above will not be detectable by
seismic refraction, and will lead to errors in the depth computations to any subsequent layers.
The processing of the acquired data is computationally intense. A ray tracing computer program,
SIPT2, is used to iteratively honor all detector information to determine dip and irregularities in the
refracting surfaces, and to be able to consider a large number of layers, where they are developed.
A picking program, with such features as zoom, filtering, time stretching, and separation of traces,
is also used.
Rock Rippabilitv Classification -In order to group the materials to be excavated in terms of difficulty
of excavation, Caterpillar has adopted a three-fold dassification scheme, the independent variable
being seismic velocity. This classification is based on experience with similar rocks in various
locals, and assumes multi or single shank D9N or equivalent equipment.
The rocks are classified as follows:
0
D9N Ripper Performance
• Multi or Single Shank No. 9 Ripper
• Estimated by Seismic Wave Velocities
Rippers
Seismic VelocJ!y
Ml!!ers Per St'COfld ~ 1000 L_.....J.. _ ___JL_ _ _.__.....L _ _Jc.__J...__...J.... _ ___J
Feel Pet Second J1 tOUO (\ 8 9 10 II 11 IJ 14
TOPSOIL
CLAY
GLACIAL Till
IGNEOUS ROCKS
GRANITE
BASALT
TRAP ROCK
SEDIMENTARY ROCKS
SHALE
SANDSTONE
SILTSTONE
CLAYSTONE
CONGLOMERATE
BRECCIA
CALICHE
LIMESTONE
SCHIST
SLATE
MINERALS & ORES
COAL
tROHORE
HIPPA.OLE NON·AIPPABLE
Marginal ripping refers to rocks in which it becomes difficult to achieve tooth penetration, sharply
reducing ripping production. Local blasting may be necessary in order to maintain a desired ripping
production rate. Non-rippable refers to rocks in which the use of heavy machinery is likely to cease
being a cost-effective method of excavation, necessitating the use of explosives to maintain a
desired excavation rate. We emphasize that the cutoffs in this classification scheme are
approximate and that rock characteristics, such as fracture spacing and orientatior], play a major
role in determining rock rippability.
5
1--------------------------------~
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Findings -Example monitor records from Line 3 are presented in figure 4 to illustrate data quality
for a typical forward, mid(X 3), and reverse shot sequence. The data recorded is displayed in
time-distance plot format in order to complete layer assignments. The curves for the forward,
mid(X 3), reverse, shots from Line 3 are displayed on the same graph (Fig. 5). After layers are
identified, the redundant data provided over each spread, are input into the iterative, ray tracing
modeling program. The resulting geologic structure sections for the eight lines are illustrated on
Figures 6 through 13. Lines 1 through 3 of the seismic lines collected illustrate a three-layer
case. These layers are interpreted to represent fill material overlying alluvium/colluvium/soil
overlying bedrock. The velocities of the layers are also well defined:
Layer
1
2
3
Velocity {ftlsec)
1690-2149
2826-4177
4585-5807
Material
Fill material
Alluvium/Colluvium/Soil
Bedrock
Lines 4 through 8 of the seismic lines collected illustrate a two-layer case. These layers are
interpreted to represent fill material overlying bedrock. The velocities of the layers are also well
defined:
Layer
1
3
Velocity {ftlsec)
1690-2149
4585-5807
Material
Fill material
Bedrock
Note: The measured seismic velocities represent average velocities of the subsurface
materials, and significant local variations may be present at any level.
Conclusions -The interpretation for the seismic lines collected agree well with the results of the
geotechnical trenching logs provided by the client with respect to lateral limits determined for the fill
and alluvium/colluvium. An exception to this was found for the baseball field portion of the survey
area where geotechnical logs indicate a thin layer of alluvium/colluvium underlying engineered fill
(suggesting a three layer case). Seismic data for this portion of the survey area suggests a two-
layer case. This may be due to a lack of significant thickness and/or velocity contrast between the
fill and alluvium/colluvium. It should also be noted that undulations for refractors presented in cross
sectional view may be the result of lateral changes in velocity and are exaggerated due to choice of
an expanded depth scale relative to the horizontal scale.
All data acquired in these surveys are in confidential file in this office, and are available for review
by your staff, or by us at your request, at any time. We appreciate the opportunity to participate in
this project. Please call, if there are questions.
Patrick F. Lehrmann
Staff Geoi/Geophysicist
G::\---~ c~:t-(J !J
Gary W. Crosby, Ph.D., GP 960
Senior Geoi/Geophysicist
6
····-···---······---------------------"
-- -- --- ---- --- -----
------------------
LINE3
0 50 J.OO J.50 200 250
60
50 ~/ 50
1=40 40
w w .... ~~ !!!:: j!: 30 30
Q. w c -
20 20
J.O J.O
0 ~*~~~~~~~~_.~-~--._~~._~~~*~~~~~~~~~*~~~~~~~~~*~ 0
SP A B C D E SP
Geo J. 2 4 6 8 J.O J.2 J.4 J.6 18 20 22 24 Geo
(DISTANCE IN FEET)
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LINE 1
c E
FIGURE&
iE 340
i 330
320
FIGURE7
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360
~ 350 ...
i!!O
~ 340 ~
330
3?0
NE
FIGURES
LINE4
B
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. .
LINE7
36D
(DISTANCE IN FEET)
FIGURE 12
""0 i
88D
(DISTANCE IN FEET)
FIGURE 13
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Leighton Consu~ing, Inc.
GENERAL EARTHWORK AND GRADING SPEOFICATIONS
Page 1 of 6
1.0
3030.1094
LEIGHTON CONSULTING, INC.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING
General
l.l Intent: These General Earthwork and Grading Specifications are for the grading and
earthwork shown on the approved grading plan(s) and/or indicated in the geotechnical
report(s). These Specifications are a part of the recommendations contained in the
geotechnical report(s). In case of conflict, the specific recommendations in the
geotechnical report shall supersede these more general Specifications. Observations of the
earthwork by the project Geotechnical Consultant during the course of grading may result
in new or revised recommendations that could supersede these specifications or the
recommendations in the geotechnical report(s).
1.2 The Geotechnical Consultant of Record: Prior to 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
geotechnically observed, mapped, elevations recorded, and/or tested include natural ground
after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial
removal" areas, all key bottoms, and benches made on sloping ground to receive fill.
The Geotechnical Consultant shall observe the moisture-conditioning and 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 Consulting, Inc.
GENEAAL EARTHWORK AND GRADING SPEORCATIONS
Page 2 of 6
2.0
3030.1094
1.3 Tb.e Eartb.work Contractor: Tb.e Earthwork Contractor (Contractor) shall be qualified,
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 sb.all 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.
Preparation of Areas to be Filled
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 I 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 of these 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 Consulting, Inc.
GENERAL EARTHWORK AND GRADING SPEOFICATIONS
Page 3 of 6
3.0
3030.1094
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 unifonn, flat, and free of uneven features that
would inhibit unifonn compaction.
2.3
2.4
2.5
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.
Benching: Where fills are to be placed on ground with slopes steeper than 5: I (horizontal
to vertical units), the ground shall be stepped or benched. Please see the Standard Details
for a graphic illustration. The lowest bench or key shall be a minimum of 15 feet wide and
at least 2 feet deep, into competent material as evaluated by the Geotechnical Consultant.
Other benches shall be excavated a minimum height of 4 feet into competent material or as
otherwise recommended by the Geotechnical Consultant. Fill placed on ground sloping
flatter than 5: I shall also be benched or otherwise overexcavated to provide a flat subgrade
for the fill.
Evaluation/ Acceptance of Fill Areas: All areas to receive fill, including removal and
processed areas, key bottoms, and benches, shall be observed, mapped, elevations recorded,
and/or tested prior to being accepted by the Geotechnical Consultant as suitable to receive
fill. The Contractor shall obtain a written acceptance from the Geotechnical Consultant
prior to fill placement. A licensed surveyor shall provide the survey control for
detennining elevations of processed areas, keys, and benches.
Fill Material
3.1
3.2
General: Material to be used as fill shall be essentially free of organic matter and other
deleterious substances evaluated and accepted by the Geotechnical Consultant prior 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.
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 I 0 vertical feet of finish grade or within 2 feet
of future utilities or underground construction.
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Leighton Consulting, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 4 of6
4.0
3030.1094
3.3 Import: If importing of fill material is required for grading, proposed import material shall
meet the requirements of Section 3 .1. The potential import source shall be given to the
Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that
its suitability can be determined and appropriate tests performed.
Fill Placement and Compaction
4. I 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
01557-07).
4.3
4.4
4.5
4.6
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 01557-07). 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.
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 01557-07.
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 fill/bedrock benches).
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 I 0 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.
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Leighton Consulting, Inc.
GENERAL EARTHWORK AND GRADING SPEOFICATIONS
Page 5 of 6
5.0
6.0
3030.1094
4.7 Compaction Test Locations: The Geotechnical Consultant shall document the approximate
elevation and horizontal coordinates of each test location. The Contractor shall coordinate
with the project surveyor to assure that sufficient grade stakes are established so that the
Geotechnical Consultant can determine the test locations with sufficient accuracy. At a
minimum, two grade stakes within a horizontal distance of I 00 feet and vertically less than
5 feet apart from potential test locations shall be provided.
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.
Excavation
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 Consulting, Inc.
GENERAL EARTHWORK AND GRADING SPEOACATIONS
Page 6 of6
7.0
3030.1094
Trench Backfills
7 .I The Contractor shall follow all OHSA and CaVOSHA requirements for safety of trench
excavations.
7.2
7.3
7.4
7.5
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 of90 percent of maximum from I foot above the top of the conduit
to the surface.
The jetting of the bedding around the conduits shall be observed by the Geotechnical
Consultant.
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 of fill.
Lift thickness of trench backfill shall not exceed those allowed m 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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FILL SLOPE
PROJECTED PLANE
1 TO 1 MAXIMUM FROM
TOE OF SLOPE TO
APPROVED GROUND
EXISTING
GROUND SURFACE
FILL-OVER-CUT SLOPE
CUT-OVER-FILL SLOPE
2' MIN.
KEY
DEPTH
15' MIN.
LOWEST
BENCH
(KEY)
REMOVE
UNSUITABLE
MATERIAL
~-REMOVE
UNSUITABLE
MATERIAL
UT FACE SHALL BE
CONSTRUCTED PRIOR
TO FILL PLACEMENT
OVERBUILD AND..,.----<;~
PROJECTED PLANE
1 TO 1 MAXIMUM
FROM TOE OF SLOPE
TO APPROVED GROUND
TRIM BACK
DESIGN SLOPE-_,.,.'>"'-•
15' MIN.
LOWEST
BENCH
{KEY)
KEYING AND BENCHING
REMOVE
UNSUITABLE
MATERIAL
FOR SUBDRAINS SEE
STANDARD DETAIL C
BENCHING SHALL BE DONE WHEN SLOPE'S
ANGLE IS EQUAL TO OR GREATER THAN 5: 1.
MINIMUM BENCH HEIGHT SHALL BE 4 FEET
AND MINIMUM FILL WIDTH SHALL BE 9 FEET.
GENERAL EARTHWORK AND
GRADING SPECIFlCA TIONS
STANDARD DETAILS A
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FINISH GRADE
--------------------------------------------------------------------------_________ -------------__________ --_ -_ -_ ---------------------_---_---------------
SLOPE FACE
c'll':·;~,~:~-~;f:!lJ11!~il~l~-::;::;'l'I:! C ' ~OVERSIZE WINDROW ~,...-,=---=--
• OVERSIZE ROCK IS LARGER THAN
8 INCHES IN LARGEST DIMENSION.
• £XCAVATE A TRENCH IN THE COMPACTED
FILL DEEP ENOUGH TO BURY ALL THE
ROCK.
• 13ACKFILL WITH GRANULAR SOIL JETTED
OR FLOODED IN PLACE TO FILL ALL THE
VOIDS.
• 00 NOT BURY ROCK WITHIN 10 FEET OF
FINISH GRADE.
• WINDROW OF BURIED ROCK SHALL BE
PARALLEL TO THE FINISHED SLOPE.
.-:·: ,,
GRANULAR MATERIAL TO BE
DENSIFIED IN PLACE BY
FLOODING OR JETTING.
DETAIL
JETTED OR FLOODED
GRANULAR MATERIAL
TYPICAL PROFILE ALONG WINDROW
OVERSIZE
ROCK DISPOSAL
GENERAL EARTHWORK AND
GRADING SPECIFICA liONS
STANDARD DETAILS B
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BENCHING
DESIGN FINISH
GRADE ----------------
SUBDRAIN
TRENCH
SEE DETAIL BELOW
FILTER FABRIC
REMOVE
UNSUITABLE
MATERIAL
(MIRAFI 140N OR APPROVED
" EQUIVALENT)•
SUBQRAIN DETAIL
COLLECTOR PIPE SHALL
BE MINIMUM 6" DIAMETER
SCHEDULE 40 PVC PERFORATED
PIPL SEE STANDARD DETAIL D
FOR PIPE SPECIFICATIONS
__ -_-::::::::::::::::::::::: 10' MIN" FILTER FABRIC
_-::-:--=-=-=-=-=-=-=-=-=-=-=-=-=BACKFILL (MIRAFI 140N OR APPROVED
-:-::::::~=~~~~~t:~~~~~~~:i~:~~~~~~~~ :~~~~~~~~~~==--EQUIVALENT)
~~~~~~~~~~~~~~~~=:-~-~.-~ : ··.: ·. :·. · .. • : .. • ~·. :.·. · ~ ·. •. ---CAL TRANS CLASS 2 PERMEABLE
, , , , • , , , , , , , • OR /12 ROCK (9FT~3/FT) WRAPPED
I I ' IN FILTER FABRIC
!---20' MIN" 5' MIN. I• PERFORATED
' NONPERFORATED 6" 0 MIN. 6• 0 MIN. PIPE
DETAIL OF CANYON SUBPRA!N OUTLET
CANYON SUBDRAINS
GENERAL EARTHWORK AND
GRADING SPECIFICATIONS
STANDARD DETAILS C
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OUTLET PIPES
4" 0 NONPERFORA TED PIPE,
100' MAX. D.C. HORIZONTALLY,
30' MAX D.C. VERTICALLY
12" MIN. OVERLAP
FROM THE TOP HOG
RING TIED EVERY
6 FEET
CALTRANS CLASS II
PERMEABLE OR #2
ROCK (3 FT'3/FT)
WRAPPED IN FILTER
FABRIC
PROVlDE POSITIVE
SEAL AT THE
JOINT
15' MIN.
TRENCH
LOWEST SUBDRAIN SHOULD
BE SITU A TED AS LOW AS
POSSIBLE TO ALLOW
SUITABLE OUTLET
T -CONNECTION
FOR COLLECTOR
PIPE TO OUTLET PIPE
L---4" MIN.
FILTE-R FABRIC
ENVELOPE (MIRAFI
140 OR APPROVED
EQUIVALENT)
BEDDING
SUBDRAIN TRENCH DETAIL
SUBDRAIN INSTALLATION -subdrain collector pipe shall be installed with perforation 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
shall be 1/4" to 1/2" if drill holes ore used. All subdrain pipes shall hove o gradient of at
least 2% towards the outlet.
SUBDRAIN PIPE -Subdroin pipe shall be ASTM D2751, SDR 23.5 or ASTM D1527, Schedule 40, or
ASTM 03034, SDR 23.5, Schedule 40 Polyvinyl Chloride Plastic (PVC) pipe.
All outlet pipe shall be placed in o trench no wide than twice the subdrain pipe. Pipe shall be in
soil of SE >/=30 jetted or flooded in place except for the outside 5 feet which shall be native
soil bock fill.
BUTTRESS OR
REPLACEMENT FILL
SUBDRAINS
GENERAL EARTHWORK AND
GRADING SPECIFICAllONS
STANDARD DETAILS D
1.-------------------------------
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RETAINING WALL
WALL WATERPROOFING ~
PER ARCHITECT'S
SPECIFICA liONS
FINISH GRADE
SOIL BACKFILL, COMPACTED TO
90 PERCENT RELATIVE COMPACTION
BASED ON ASTM D1557
3" MIN.
COMPETENT BEDROCK OR MATERIAL
AS EVALUATED BY THE GEOTECHNICAL
CONSULTANT
NOTE: UPON REVIEW BY THE GEOTECHNICAL CONSULTANT,
. COMPOSITE DRAINAGE PRODUCTS SUCH AS MIRADRAIN OR
J-DRAIN MAY BE USED AS AN ALTERNATIVIE TO GRAVIEL OR
CLASS 2 PERMEABLE MATERIAL. INSTALLATION SHOULD BE
PERFORMED IN ACCORDANCE WITH MANUFACTURER'S
SPECIFICA liONS.
RETAINING WALL
DRAINAGE DETAIL
GENERAL EARTHWORK AND
GRADING SPECIFICA TlONS
STANDARD DETAILS E