HomeMy WebLinkAboutCT 06-16; Carlsbad Boat Club; Geotechnical Report; 2007-03-06GEOTECHNICAL REPORT
PROPOSED CONDOMINIUM COMPLEX
4509 ADAMS STREET
CARLSBAD, CALIFORNIA
MARCH 2007
PREPARED FOR:
VIP PARTNERS
1861 SOUTHVIEW DRIVE
CARLSBAD, CALIFORNIA
PREPARED BY:
GeoLogic Associates
16885 West Bernardo Drive, Suite 305
San Diego, California 92127
(858)451-1136
HL(Jh!VED
NAR 2 0 20.^7
UTY OF CAFILSBAD
PLANNING DEPT
GeoLogic Associates
Geologists, Hydrogeologists and Engineers
March 6, 2007
Project No. 2007-0014
Mr. Jim Courtney
VIP Partners
1861 Southview Drive
Carlsbad, California 92008
GEOTECHNICAL REPORT
PROPOSED CONDOMINIUM COMPLEX
4509 ADAMS STREET
CARLSBAD, CALIFORNIA
In accordance with your request and authorization, GeoLogic Associates (GLA), has conducted
a geotechnical investigation for the proposed condominium complex at 4509 Adams Street m
Carlsbad, California (Figure 1, Vicinity Map).
Based on the results of GLA's study, it is our opinion that the proposed site improvement is
feasible fi-om a geotechnical perspective provided the recommendations presented, herein, are
incorporated into the design and construction of the project. The accompanying report provides
geotechnical conclusions and recommendations relative to the proposed development.
We appreciate this opportunity to be of service. If you have any questions regarding this report,
please do not hesitate to contact the undersigned.
GeoLogic Associates
Ted M. Primas
Project Geologist Supervising Geotechnical Engineer
Distribution: (4) Addressee
Attachments: Figure 1 - Vicinity Map
Figure 2 - Boring Location Map
Figure 3 - Cross Section A-A'
Figure 4 - Shoring Design
Appendix A - Boring Logs
Appendix B - Laboratory Testing Procedures and Test Results
Appendix C - Seismic Analysis
16885 W. Bernardo Dr., Suite 305, San Diego, CA 92127 Phone: (858) 451-1136 Fax: (858) 451-1087
1.0 INTRODUCTION
1.1 Purpose and Scope
This report presents the results of our geotechnical investigation for the proposed condominium
complex at 4509 Adams Street in Carlsbad, California (Figure 1). The proposed development
will include constiuction of a four level (three living levels and one parking level) condominium
complex. The site is currently occupied by two existing structures. The residential structure is
proposed to be razed and the boathouse will remain. Investigation of the boathouse was not
within the scope of this report.
This investigation was performed in accordance with the GLA's proposal. Our scope of services
specifically included:
• Review of available pertinent, published and unpublished geotechnical literature and maps.
• Field reconnaissance of the existing onsite geologic/geotechnical conditions.
• Subsurface exploration by a GLA geologist consisting of excavation, logging and sampling
of four exploratory borings across the site to a maximum depth of 36.5 feet below existing
grade.
• Laboratory testing of representative soil samples obtained fi-om the subsurface exploration.
• Analysis of the geotechnical data obtained fi-om the field sampling and laboratory testing.
• Preparation of this report presenting our findings, conclusions, and geotechnical
recommendations with respect to the proposed site improvements.
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2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING
2.1 Document Review
Available geologic and geotechnical literature pertaining to the project site and surrounding areas
was reviewed. These docxmients included published topographic maps, geologic maps, and
reports. Specific documents reviewed are referenced in Section 8.0.
2.2 Site Reconnaissance
GLA personnel visited the site to observe and map geologic conditions. Swface conditions were
noted, including the general geologic and topographic setting, surface soils and related
conditions. The exploratory boring locations were selected as well.
2.3 Subsurface Exploration
Subsurface exploration consisted of excavating four exploratory borings with a Mobil B-53 drill
rig. All borings were backfilled prior to the GLA representative leaving tiie site.
The excavation of the borings was performed under the supervision of a GLA geologist who also
logged the borings and obtained samples for subsequent examination and laboratory testing.
Disturbed samples were obtained from the borings for visual observation and testing in the
laboratory. Relatively undisturbed samples were also obtained fi-om Modified CaUfomia
Samplers.
Subsurface materials were visually classified in the field in accordance with standard engineering
and geologic practices. Soil samples were classified using the Unified Soil Classification System
explained in Appendix A. Details of the subsurface exploration and exploratory boring logs are
presented in Appendix A.
2.4 Laboratory Testing
Laboratory tests were performed to provide geotechnical parameters for engineering analyses.
The testing program was designed to fit the specific needs of this project. Tests of selected
samples retiieved fi-om tiie borings included direct shear, expansion index testing, R-Value, and
corrosivity assessments (including soluble sulfate, pH, and minimum resistivity). The results of
the tests are summarized in Appendix B.
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3.0 SITE CONDITIONS
3.1 Site Location/Conditions and Proposed Development
The project site is located on 4509 Adams Street in Carlsbad, California (Figure 1). The site is
bounded to the north by Adams Street, to the south by the Agua Hedionda Lagoon, and the east
and west by residential construction. The site slopes steeply to the south. A single-family
residence occupies the central portion of the site and a smaller boathouse lies to the south just
north of the lagoon. Elevations range fi-om 50 feet near the northern portion of the site (near
Adams Stieet) to approximately 10 feet mean sea level near the boathouse.
The single-family residence will be removed for the new development and the boat house will
remain. The lowest finish floor of the parking level is anticipated to be 8 feet mean sea level
necessitating an excavation on the order of 40+ feet fi-om the street level to the lowest finish
floor. A tie-back wall is anticipated to support this excavation. A concrete driveway will
coimect Adams Stieet to the parking level. The proposed construction layout for the site is
shown on Figure 2.
3.2 Subsurface Conditions and Groundwater
The subject site is located in a coastal area of the Peninsular Ranges Geomorphic Province of
California. This area extends fi-om the coastal plain northeastward to the Elsinore fault zone.
The Carlsbad area is characterized by low rolling hills separated by the intermediate to broad
valleys inland and lagoons near the coasL In general, this area is imderlain by the Tertiary-aged
Santiago Formation, capped by Quaternary-aged Terrace Deposits, colluvium, and fill soils. A
description of these units as encountered on the site follows.
Fill soils were encountered in all four borings. The fill soils ranged fi-om one to four feet thick
and were described as stiff clayey silt, fine clayey sand, and silty sand. These materials are not
considered suitable for support of new fill soils or the proposed improvements.
Colluvial soils were encountered in all borings except for B-2. Colluvium is derived fi-om
weathering of imderlying material and downslope movement of these materials. The colluvium
was described as stiff clayey silt to loose clayey sand and was encountered below the fill soils
ranging fiom 2 to 6 feet thick. The colluvium in the area of Boring B-2 is anticipated to be
removed during excavation. The colluvium in the area of Borings B-3 and B-4 is anticipated to
be removed and recompacted during earthwork construction. In their current condition, these
materials are not considered suitable for support of new fill soils or proposed improvements.
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Terrace Deposits were encountered below the fiU/coUuvium soils in the area of Borings B-1 and
B-2. These materials are described as medium dense, reddish brown, fine silty sandstone. These
materials are also anticipated to be removed during earthwork construction.
The Santiago Formation is the bearing unit or "bedrock" material on the site. This formation is
described as yellowish gray fine silty sandstone and has adequate bearing capacity. This
formation is anticipated to be exposed at the lowest finish floor elevation except for the extieme
southern portion of the parking level footprint where some fill/colluvial soils may be
encountered.
Groundwater was not encountered in the borings on the site. Minor seepage was encountered at
a depth of 7.5 feet (elevation of 3.5 feet mean sea level) in Boring B-3. The groundwater level
will fluctuate seasonally, and considering the time of year and the last few years of below average
precipitation, the groundwater table at the time of consfaiiction will likely be higher.
Groundwater/seepage will likely be encotintered during excavation/recompaction at the southern
portion of the site and special construction dewatering techniques may have to be employed to
contioi groundwater during the anticipated removals especially at the southern portion of the
parking level.
4.0 FAULTING AND SEISMICITY
4.1 Faulting
Our discussion of faults on the site is prefaced with a discussion of California legislation and
policies concerning the classification and land-use criteria associated with faults. By definition
of the California Geological Survey, an active fault is a fault that has had surface displacement
within Holocene time (about the last 11,000 years). The state geologist has defined a potentiallv
active fault as any fault considered to have been active during Quaternary time (last 1,600,000
years). This definition is used in delineating Earthquake Fault Zones as mandated by the Alquist-
Priolo Geologic Hazards Zones Act of 1972 and as subsequently revised in 1975,1985, 1990,
1992, and 1994. The intent of this act is to assure that unwise urban development and certain
habitable structures do not occur across the tiaces of active faults. The subject site is not
included within any Earthquake Fault Zones as created by the Alquist-Priolo Act.
Our review of available geologic literature (Section 8.0) indicates that there are no known major
or active faults on or in the immediate vicinity of the site. The nearest active regional fauhs are
the Rose Canyon Fault Zone, the Newport-Inglewood Fault (offshore), the Coronado Bank Fault,
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and the Elsinore Fault Zone located approximately 5.0, 6.0, 21.1, and 24.1 miles fi-om tiie site,
respectively.
4.2 Seismicity
The site can be considered to lie within a seismicaliy active region, as can all of Southern
California. From a deterministic standpoint. Table 1 identifies potential seismic events that
could be produced by the maximum earthquake event.
Table 1
Seismic Parameters for Active Faults (Blake, 2004a and 2004b)
Fault Zone
(Seismic Source)
Distance
to Site
(mUes)
SUp
Rate
(nun/yr)
*
Maximum Earthquake Event
Design Eartliquake (UBC,
1997/CBC, 2001) Fault Zone
(Seismic Source)
Distance
to Site
(mUes)
SUp
Rate
(nun/yr)
*
Moment
Magnitude
Pealc Horizontal
Ground Acceleration (g)
Peak Horizontal Ground
Acceleration (g)
Rose Canyon 5.0 1.5 7.2 0.34
0.26
Newport-Inglewood
(Offshore) 6.0 1.5 7.1 0.29
0.26
Coronado Bank 21.1 3.0 7.6 0.16
0.26
Elsinore 24.1 5.0 7.1 O.U
0.26
Notes: * CDMG, 1996.
The maximum earthquake is defined by the State of California as the maximum earthquake that
appears capable of occurring under the presently understood tectonic fi-amework. Site-specific
seismic parameters included in Table 1 are the distances to the causative faults, earthquake
magnitudes (Mw), and expected ground accelerations, which were determined with EQFAULT
software (Blake, 2004a).
As indicated in Table 1, the Rose Canyon Fault is the active fault considered to have the most
significant effect at the site fi-om a design standpoint. The maximum earthquake from the fault
has a 7.2 moment magnitude, generating a peak horizontal groxmd acceleration of 0.34g at the
project site. Secondary effects associated with severe ground shaking following a relatively large
earthquake on a regional fault that may affect the site include ground lurching and shallow
ground rupture, soil liquefaction and dynamic settlement, seiches and tsunamis. These secondary
effects of seismic shaking are discussed in the following sections.
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From a probabilistic standpoint, the design ground motion (per UBC, 1997/CBC, 2001) is
defined as the ground motion having a 10 percent probability of exceedance in 50 years (475-year
retum period). This ground motion is referred to as the design earthquake. The design
earthquake ground motion at the site is predicted to be 0.26g. The effect of seismic shaking may
be mitigated by adhering to the Uniform Building Code and state-of-the-art seismic design
parameters of the Stractural Engineers Association of California. The site is located within
Seismic Zone 4 (UBC, 1997/CBC 2001, Figure 16-2).
4.2.1 Lurching and Shallow Ground Rupture
Soil lurching refers to the rolling motion on the ground surface by the passage of seismic surface
waves. Effects of this nature are likely to be significant where the thickness of soft sediments
vary appreciably under stmctures. Damage to the proposed development should not be
significant since a relatively large differential thickness of surficial materials does not exist at the
site.
4.2.2 UBC Criteria
The site soil parameters in accordance with UBC 1997/CBC, 2001 are as follows:
Seismic Zone = 4 (Figure 16-2; UBC, 1997 /CBC, 2001)
Soil Profile Type = So (Table 16-J; UBC, 1997/CBC, 2001)
Slip Rate (Rose Canyon Fault), SR, (Table 16-U) = 1.5nim per year (CDMG, 1996)
Seismic Source Type (Table 16-U, UBC, 1997/CBC, 2001) = B
Na = 1.0 (Table 16-S; UBC, 1997, CBC, 2001)
Nv = 1.1 (Table 16-T; UBC, 1997, CBC, 2001)
4.23 Historical Seismicity
The historic record of earthquakes in southern California for the past 200 years has been
reasonably well established. More accurate instrumental measurements have been available
since 1933. Based on recorded earthquake magnitudes and locations, the area may be vulnerable
to moderate seismic ground shaking during the design life of the project.
4.2.4 Liquefaction and Dynamic Settlement
Liquefaction is a phenomenon in which soils lose shear stiength for short periods of time during
an earthquake, which may result in very large total and/or differential settiements for stmctures
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founded on liquefying soils. In order for the potential effects of liquefaction to be manifested at
the ground surface, the soils generally have to be granular, loose to medium dense, saturated
relatively near the ground surface, and must be subjected to a sufficient magnitude and duration
of shaking.
Since the stmcture will be founded on competent materials of the Santiago Formation, the
potential for large-scale liquefaction effects to the proposed surface improvements is low. It
should also be understood that much of Southern Cahfomia is an area of moderate to high
seismic risk and is not generally considered economically feasible to build stmctures totally
resistant to earthquake related hazards. However, current state-of-the-art standards for design
and constmction are intended to reduce the potential for major stmctural damage.
Evaluation of liquefaction effects underljdng the boat house in not within the scope of this report.
4.2.5 Ground Surface Rupture
Since no active faults are known to tiansect the site, ground surface mpture as a result of
movement along known faults is considered unlikely.
4.2.6 Landslides
The site is located in a sloping area with favorable geologic stmcture and rock types.
Accordingly, the potential for landslides or other slope instability problems is considered low.
4.2.7 Tsunamis and Seiches
A tsunami (incorrectly called a tidal wave) is a sea wave generated by submarine earthquakes,
landslides or volcanic activity which displaces a relatively large volume of water in a very short
period of time. Several factors at the originating point such as; earthquake magnitude, type of
fault, depth of earthquake, focus, water depth, and the ocean bottom profile all contribute to the
size and momentum of a tsunami (fida, 1969). In addition, factors such as the distance away
from the originating point, coastline profile (including width of the continental shelf), and angle
at which the tsunami approaches the coastline also affect the size and severity of a tsunami.
There have been over 500 tsunamis reported with recorded history, most of them occurring
within the Pacific Ocean, however, one of the largest tsunamis ever recorded (December 2004)
recently occurred in the Indian Ocean as a result of a Magnitude 9.0 earthquake event This
event was the fourth largest earthquake to occur in the world in the last 100 years (USGS,
2005b). Large tsimamis have been occurring somewhere in the Pacific Basin at an average rate
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of roughly 1 every 12 years.
Table 2 shows a number of great tsunamis representing each of the major generating zones
within the Pacific Basin (Joy, 1968).
Table 2
Major Tsunamis Recorded in San Diego County*
San Diego La JoUa
Event/Location Date Arrival
Time
(how)
Wave
Height (m)
Arrival
Time
(hour)
Wave
Height (m)
Prince William Sound,
Alaska
3/27/64 +6.2 1.1 +5.8 0.7
Southern Chile 5/22/60 +14 1.4 +14 1.0
Aleutian Islands 3/9/57 +6.9 0.5 +6.6 0.6
Kamchatka 11/5/52 +9.6 0.7 +9.6 0.2
Aleutian Islands 4/1/46 ? 0.4 +6.2 0.4
Sanriku, Japan 3/3/33 ? Unknown ? 0.3
Cape Arguello,
California**
11/24/27 ? 0.05 +0.98 0.05
* Joy, 1968
** This is the only well documented locally generated tsunami in CaUfomia history.
Tsunami wave heights and nmup elevations experienced along the San Diego area coastline
during the last 170 years have fallen within the normal range of tidal fluctuations (approximately
9 feet). Southern California is oriented obliquely (i.e. not directly in line) with the major
originating tsunami zones, it has a relatively wide and mgged continental shelf (or borderland)
which acts as a diffuser and reflector of remotely generated tsunami wave energy (Joy, 1968).
These conditions, in addition to the geologic and seismic conditions (such as the strike-slip fault
regime, and the scarcity of large submarine earthquakes) along the coastline also tend to
minimize the likelihood of a large tsunami at the site. The USC Tsunami Research Group is
currently working on a series of tsunami inundation maps for southem California (USC, 2005).
The site is within the Agua Hedionda Lagoon and tsunami predictions have not been found in the
literature. It is likely that the potential for significant tsunami effects in the lagoon are relatively
low since the site is protected from direct wave action, however, the tsunami wave height may be
dampened or amplified by the confines of the lagoon. Data from coastal studies will be
presented since the effects of wave heights in the lagoon are not well understood.
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McCuUough (1985) predicts the average tsunami height in the San Diego region for an event
with a 10% probability of exceedence in 50 years (approximately 500-year retum period) is
approximately +13 to +15 feet mean sea level. Work by Garcia and Houston (1974) presents a
similar 500-year retum period wave height ranging from +11 to +13 feet mean sea level. Based
on these reports and the finish floor elevation (parking level) of 8 feet mean sea level, the site is
below the 500-year retum period tsunami wave height. Garcia and Houston (1974) calculates the
100-year retum period wave height at approximately 6 feet which coupled with a maximum high
tide elevation of 5 feet mean sea level, is roughly 3 feet above the lowest finish (parking level)
floor. Accordingly, based on the above data, there is a moderate to high potential for tsunami or
storm surge waves at the site ^ the parking level, but not within the Hii*ing li^i^ (assuming that
the tsimami energy is not dampened by entering the lagoon).
Seiches are defined as oscillations in a semi-confined body of water (such as a lake or lagoon)
due to earthquake shaking or fault mpture. Seiches with a wave height on the order of tsunami
wave heights may also affect the site.
4.2.8 Flooding
I the maximum high tide level of 4.9 feet mean sea level and the site^levation of 8 fe^
urge of over 3+ feet will be necessary to flood the iBS^'^^iC ^"f^^otential for a storm
Based on
a storm surge of over 3+ feet will be necessary to flood the feSSlfy flfli "TTie'potential
surge greater than 3 feet is low to moderate. The potential is further reduced by the limited
likelihood of the storm surge occurring at the same time as the asfronomical high tide event and
the dampening effects of the lagoon.
4.2.9 Expansive Soils
Samples of the near-surface fill soils were collected from the borings. The results indicate that
the expansion potential of the soils to be exposed at the lowest garage level is in the low range
(based on ASTM D4829). The expansion test results are presented in Appendix B.
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5.0 CONCLUSIONS
Based on the results of our geotechnical review of the site, it is our opinion that the proposed
development is feasible from a geotechnical standpoint, provided the following conclusions and
recommendations are incorporated into the project plans and specifications. The following is a
summary of the geotechnical factors that may affect development of the site.
• An excavation (on the order of 40+ feet) is necessary to reach the lowest proposed garage
floor level. Tie-back shoring is anticipated due to the limited horizontal distance from the
street to northem wall of the garage. After the excavation is completed, the stmcture is
anticipated to be foimded on competent materials of the Santiago Formation. The saturated
foundation materials in a limited area in the extieme southem portion of the garage may need
to be removed and recompacted using dewatering techniques or the materials maybe
"bridged" with a stmctural (self-supporting) floor slab. All the footings of the stmcture
should be deepened to be founded in the Santiago Formation. This may necessitate deeper
footings along the southem wall of the stmcture.
• In general, the existing onsite soils appear to be suitable material for stmctural fill
constmction provided they are relatively free of organic material, debris, and rock fragments
larger than 6 inches. The onsite fill and colluvium soils should be removed (down to
competent material) and recompacted prior to placement of fill soils or improvements.
Removals may range up to 9+ feet and locally be greater. Fill soils should be removed and
recompacted to a minimum 90 percent relative compaction.
• Based on our subsurface exploration and laboratory testing, the proposed pad grade soils are
generally considered to have a very low to low expansion potential (Appendix B) and a
negligible potential for sulfate attack on concrete. The onsite soils are considered to have a
very high potential for corrosion to buried uncoated metal conduits.
• The site is not in an area of known active faults. The potential for geologic hazards to
significantly affect the proposed constmction is low. The design earthquake, having a 10
percent probability of being exceeded in 50 years, is expected to produce a peak ground
surface acceleration at the site of 0.26g. The garage floor level may be affected by tsunamis
or flooding during the project lifetime.
• Groundwater/seepage was encountered at a depth of 7.5 feet (elevation of 3.5 feet mean sea
level) in Boring B-3. The groundwater level will fluctuate seasonally, and considering the
time of year and the last few years of below average precipitation, the groundwater table at
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the time of constmction will likely be higher. Groundwater/seepage will likely be
encountered during excavation/recompaction at the southem portion of the site and special
constmction dewatering techniques may have to be employed to confrol groundwater seepage
during the anticipated removals especially at the southem portion of the parking level.
6.0 RECOMMENDATIONS
6.1 General Earthwork
Earthwork should be performed in accordance with the project specifications and the following
recommendations.
6.1.1 Site Preparation
Prior to grading, the site should be cleared of existing surface/subsurface obstmctions, septic
systems, foundations, stmctures, etc. Vegetation, oversize material, and debris should be
disposed off site. Holes resulting from removal of buried obstmctions such as foundations or
below-grade stmctures that extend below finished site grades should be filled with properly
compacted soil under the observation and testing of the geotechnical engineer.
6.1.2 Removals and Treatment of Transition Condition
Since the existing fill and colluvium soils were observed to be dry, loose, and have small pores,
we recommend that the fill soils and colluvium be removed down to competent material (where
otherwise not removed by the proposed excavation), moisture-conditioned, and recompacted
prior to the placement of stmctural fills or the proposed site improvements. Removals may range
up to 9 feet and may be locally deeper. Where these removals occur adjacent to the property
lines, shoring may be necessary. All excavation/removal bottoms should expose firm and
competent formational materials and be observed by a representative of the geotechnical
engineer.
To reduce the potential for differential settlement due to a tiansition (cut/fill) condition, we
recommend that all the footing be founded into the Santiago Formation. The fill/colluvial soils
in the southem portion of the site should be removed and recompacted and recompacted to a
minimum relative compaction of 90%. This removal should extend a minimum of 5 feet (but at
least equal to the depth of the removals) beyond the building perimeter and all settlement-
sensitive stmctures. Dewatering may be necessary in selected areas to facilitate constmction and
aid in recompaction. As an altemative, the soils may be left in their current condition and a
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deepened footing (or pier and grade beam supported footing) with a stmctural (self-supporting)
slab may be designed to "bridge" these soils. Flatwork and other improvements in this area
should also be designed with a deepened footing or be designed to be "floating".
6.1.3 Structural FiUs
The onsite soils are generally suitable for use as compacted fill provided they are free of organic
material and debris. Material greater than 6 inches in maximum size should not be placed within
5 feet of the pad grade. Asphalt concrete and concrete should not be placed in stmctural fills.
The area to receive fill should be scarified to a minimum depth of 6 inches, brought to near
optimum moisture content, and recompacted to at least 90 percent relative compaction (based on
Modified Proctor, ASTM D1557). Fill soils should be placed at a minimum of 90 percent
relative compaction (based on Modified Proctor, ASTM D1557) near optimum moisture content.
The optimum lift thickness to produce a uniformly compacted fill will depend on the type and
size of compaction equipment used. In general, fill should be placed in uniform lifts not
exceeding 8 inches in thickness.
All import soils should have an expansion index less than 20 (per ASTM D4829). These soils
should be tested by the geotechnical consultant prior to site delivery for conformance to the
above recommendations.
Fills placed within 5 feet of finish pad grade should consist of soils with an expansion potential
less than 20 based on UBC Standard 18-2 (ASTM D4829) and with a maximum particle size less
than 6 inches.
6.1.4 Trench BackfiU
The onsite soils may generally be suitable as tiench backfill provided they are screened of rocks
and other material over 6 inches in diameter and organic matter. Trench backfill should be
compacted in uniform lifts (not exceeding 8 inches in compacted thickness) by mechanical
means to at least 90 percent relative compaction (ASTM D 1557).
6.2 Foundation Design
It is assumed that soil with a low expansion potential (less than 50 per ASTM D4829) will be
exposed at the proposed garage level subgrade. Therefore, for design purposes, we provide the
following foundation design parameters based on a low expansion potential.
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Footings bearing in properly compacted fill should have a minimum depth of 24 inches below the
lowest adjacent compacted soil grade. At a depth of 24 inches, footings may be designed using
an allowable soil-bearing value of 3,500 pounds per square foot (psf). At a depth of 30 inches,
an allowable bearing capacity of 4,000 psf may be used. These values may be increased by one-
third for loads of short duration including wind or seismic forces.
Continuous and isolated-spread footings shall have a minimum base dimension no less than 18
inches and 24 inches, respectively and should be reinforced in accordance with the
recommendations of the stmctural engineer and the latest edition of the Uniform Building
Code/CBC.
Continuous footings should have minimum reinforcement of four No. 5 rebars; two near the top
and two near the bottom of the footing. Stmctural requirements may necessitate greater
reinforcement. If founded near the top of slopes, footings, as well as retaining stmctures should
have a minimum 10-foot setback (measured horizontally) from the base of the footing to
daylight. Our preliminary foundation design recommendations are summarized in Table 3
below:
Table 3
— Foundation Design Recommendation Summary
Minimum Depth: 24 inches below lowest adjacent soil grade (minimum)
Minimum Width: 18 inches
Continuous Reinforcement: Four No. 5 rebars (2 near top and 2 near bottom)
mm Footings: Slope Setback: 10-foot minimum
Allowable Bearing Capacity: 3,500 psf (at 24 inches deep), 4,000 psf (at 30 inches deep)
Minimum Depth: 24 inches below lowest adjacent soil grade (minimum)
mm Minimum Width: 24 inches
Isolated Spread Reinforcement: Per structural engineer
Footings: Slope Setback: 10-foot minimum
Allowable Bearing Capacity: 3,500 psf (at 24 inches deep), 4,000 psf (at 30 inches deep)
MM Garage Slab-on-Minimum Thickness: 5 inches
Grade Floor: Minimimi Reinforcement: No. 4 rebars at 18 inches on center (each way)
m Design Settlement See Section 6.4
Garage slabs should have a minimum thickness of 5 inches. If heavy tmck or RV loads are
anticipated, the slab thickness may be increased based on actual design by the stmctural engineer
to accommodate these greater loads. Minimum slab reinforcement should consist of No. 4 bars
at 18 inches on center (each way). We emphasize that it is the responsibility of the contiactor to
ensure that the slab reinforcement is placed at slab mid-height. Slabs should be underlain by a 2-
inch layer of sand (SE minimum of 30) to aid in concrete curing and to act as a capillary break.
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GeoLogic Associates
which is underlain by a 6-mil (or heavier) moisture barrier (to reduce the potential for formation
of salt crystals or white efflorescence). The moisture barrier should be underlain by an additional
2-inch layer of clean sand to protect the moisture barrier. All penetiations through the moisture
barrier and laps should be sealed. Since the garage level has the potential for inundation by
water, a method to remove accumulated water may be pmdent.
Our experience indicates that use of 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/cement ratio, 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 concrete (not exceeding 4 inches at the time of placement) can
reduce the potential for shrinkage cracking.
Moisture barriers can retard, but not eliminate vapor movement from the underlying soils up
through the slab. In living areas, we recommend that the floor-covering contractor test the
moisture vapor flux rate prior to attempting application of moisture-sensitive flooring.
'Breathable' floor covering or special slab sealants should be considered if the vapor flux rates
are high. Floor covering manufacturers should be consulted for specific recommendations. If
tile or other crack or movement-sensitive flooring is planned, a slipsheet should be used.
Flexible joint material should be used where crack-sensitive flooring overlies concrete joints.
6.3 Moisture Conditioning
The upper 12 inches of subgrade soils underlying conventionally reinforced foundation systems
and exterior flatwork should be brought to at least optimum moisture content prior to placement
of the moisture barrier and slab concrete. This should be checked by the soil technician prior to
concrete placement.
6.4 Settlement
The recommended allowable bearing capacity is generally based on a total static settlement of
one inch. Differential (static) settlement is likely to be approximately one-half of the total
settlement occurring shortly after application of the building loads.
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GeoLogic Associates
6.5 Lateral Earth Pressures and Resistance
Embedded stiaxctural walls should be designed for lateral earth pressures exerted on them. The
magnitude of these pressures depends on the amount of deformation tiiat the wall can withstand
under load. If the wall can yield enough to mobilize the full shear stiength ofthe soil, it can be
designed for "active" pressure. If the wall cannot yield under the applied load, tfie shear stiength
of tiie soil cannot be mobilized and the earth pressure will be higher. Such walls should be
designed for 'at rest' conditions. If a stiucture moves toward the soils, the resulting resistance
developed by the soil is the 'passive' 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 gravel, onsite or
import soils of low expansion potential (less than 50 per ASTM D4829) is presented in the
following table.
Table 4 - Lateral Earth Pressures
Equivalent Fluid Weight (pcf)
Condition Level 2:1 Slope
Active 40 60
At-Rest 60 70
Passive 350 (Maximum of 3 ksf) -
The above values assume free-draining conditions. If conditions other than those covered herein
are anticipated, the equivalent fluid pressure values should be provided on an individual case
basis by the geotechnical engineer. A surcharge load for a restiained or unrestiained waU
resulting from automobile traffic may be assumed to be equivalent to a uniform pressure of 100
psf which is in addition to the equivalent fluid pressures given above. All retaining wall
stiuctures should be provided witfi appropriate drainage and waterproofing. Wall backfiU should
be compacted by mechanical methods to at least 90 percent relative compaction (based on ASTM
Test Method D1557).
Wall footing design and setbacks should be performed in accordance witii the previous
foundation design recommendations and reinforced in accordance witii stiiictural considerations.
Soil resistance developed against lateral sti-uctural movement can be obtained from the passive
pressure value provided above. Further, for sliding resistance, a fiiction coefficient of 0.35 may
be used at the concrete and soil interface. These values may be increased by one-third for loads
of short duration including wind or seismic loads. The total resistance may be taken as the sum
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GeoLogic Associates
of the frictional and passive resistance provided that the passive portion does not exceed two-
thirds of the total resistance.
6.6 Slope Excavation and Shoring
Slope excavations may be utilized when adequate space allows. Based on our borings and
laboratory testing, we provide the following recommendations in Table 5 for sloped excavations
in fill soils or competent formational materials without seepage conditions.
Table 5
Temporary Excavation Slopes
Excavation
Depth (feet)
Maximum Slope Ratio in Competent
Bay Point or Santiago Formational
Materials (Horizontal to Vertical)
Maximum Slope Ratio
in Existing Fill SoUs
(Horizontal to Vertical)
0-3 Vertical 1:1
3-10 3/4:1 1:1
10-25 1:1 N/A
Grreater than 25 1-1/2:1 N/A
We do not recommend surcharge loading or equipment lay-down within five feet of the top of slope.
Care should be taken during excavation adjacent to the existing stmctures so that undermining does
not occur. Where fill/colluvium exists above formational materials, the "competent person" (as
defined by OSHA) should observe the slope on a daily basis for signs of instability.
If sufficient horizontal distance does not allow slope layback in accordance with Table 5, we
recommend that slopes be retained either by a cantilever shoring system deriving passive support
from cast-in-place soldier piles (lagging-shoring system) or a restrained tie-back and pile system.
Lagging is recommended due to the friable nature of the soil. Based on our experience with
similar projects, if lateral movement of the top of the shoring system on the order of one to two
inches cannot be tolerated, we recommend the utilization of a restiained tie-back and pile system.
Shoring of excavations of this size is typically performed by specialty contractors with
knowledge of the San Diego County area soil conditions.
We recommend that the shoring contiactor provide the excavation shoring design. Tie-back
shoring may be designed in accordance with the lateral pressures presented below and
graphicaUy illustiated in Figure 4.
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GeoLogic Associates
Tie-Back Shoring Svstem
-At-Rest Pressure = Trapezoidal distribution of 25H, starting at 0 at the top of the
distribution, increasing to 25H at 0.2H from the top ofthe wall, uniform at 25H until
0.2H from the base of the wall and then decreasing to 0 at the bottom of the wall.
-Passive Pressure = equivalent fluid weight of400 pcf above the groundwater table and
200 pcf below the groundwater table, to a maximum value of 6,000 psf
-H = Height of excavation, feet
All shoring systems should consider adjacent surcharging loads. For design of tie-backs, we
recommend an allowable concrete-soil bond sfress of2,500 psf of the concrete-soil interface area
for grouted anchors. This value is based on a minimum 20-foot-long anchor beyond the active
zone and thus should be considered only behind the 40-degree line (measured from the vertical)
up from the base of the footing (Figure 4). This portion should also be used for calculating
resisting forces. Tie-back anchors should be individually proof-tested to 150 percent of design
capacity. Further details and design criteria for tie-backs can be provided as appropriate. Since
design of retaining systems is sensitive to surcharge pressures behind the excavation, we
recommend that this office be consulted if unusual load conditions are anticipated. Care should
be exercised when drilling or excavating into the on-site soils since caving or sloughing of these
materials is possible. Field testing of tie-backs and observation of soldier pile excavations
should be performed during constmction.
Settlement monitoring of adjacent sidewalks and stmctures should be considered to evaluate the
performance of the shoring. Shoring of the excavation is the responsibility of the contractor.
Extieme caution should be used to minimize damage to existing pavement, utiUties, and/or
stmctures caused by settlement or reduction of lateral support. Piers should extend a minimum
of five feet below the bottom of the proposed footings. The bearing capacity values in Section
6.2 may be used to design the piers. An allowable skin fiiction along the side of the pier of 300
pounds per square foot may also be used for pier design provided the area where the fiiction is
calculated is a minimum of four feet below the base of the proposed footings. The pier spacing
should be determined by the project stmctural engineer. Special sheathing and/or corrosion
protection should be considered for the beams and tiebacks.
6.7 Soil Corrosivity
In general, soil environments that are detrimental to concrete have high concentiations of soluble
sulfates and/or pH values of less than 5.5. Table 19-A-4 of UBC, 1997 provides specific
guidelines for the concrete mix-design when the soluble sulfate content of the soil exceeds 0.1
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GeoLogic Associates
percent by weight or 1000 ppm. The results of our laboratory tests on representative soils from
the site indicated a soluble sulfate content ranging from 74 to 613 indicating that the concrete
should be designed in accordance with the Negligible Category of Table 19-A-4 of UBC, 1997.
The test results also indicate a minimum resistivity ranging from 680 to 1,525 ohm-cm, which is
considered to present very high corrosion potential to buried metals. The test results are
provided in Appendix B. For the appropriate evaluation and mitigation design for other
substances with potential influence from corrosive soils, a corrosion engineer may be consulted.
6.7 Pavement Design
For driveways, a minimum concrete pavement thickness of 5 inches is recommended. For
delivery areas, frash areas, and RV or heavy tmck tiaffic areas utilized by the deUvery tmcks, we
recommend a minimum section of 7 inches of Portland cement concrete (P.C.C.) over 2 inches of
Class 2 aggregate base. The P.C.C. in the above pavement sections should be provided with
appropriate steel reinforcement and crack-control joints as designed by the project stmctural
engineer. If sawcuts are used, they should be a minimum depth of 1/3 the slab thickness and
made within 8 hours of concrete placement. We recommend that sections be as nearly square as
possible. A concrete mix with a minimum 28-day stiength of 3,250 psi should be utilized.
P.C.C, 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 (Caltians) and
American Concrete Institute (ACI) codes. In accordance with the Standard Specifications for
Public Works Constmction "Greenbook", the upper 6 inches of subgrade soils should be
moisture conditioned and compacted to at least 95 percent relative compaction based on ASTM
Test Method D1557 prior to placement of aggregate base. The base layer should be compacted
to at least 95 percent relative compaction as determined by ASTM Test Method D1557.
Untieated Class 2 aggregate base should meet the four criteria of Section 26-1.02A of the most
recent Caltrans specifications and the Greenbook standards.
We recommend that the curbs, gutters, and sidewalks be designed by the civil engineer or
stmctural engineer. We suggest contioi joints, at appropriate intervals, as determined by the civil
or stmcture engineer, be considered. We recommend 6x6-6/6 welded-wire mesh reinforcement
and a minimum thickness of 4 inches for sidewalk slabs. If pavement areas are adjacent to
landscape areas, we recommend steps be taken to prevent the subgrade soils from becoming
saturated. The upper 12 inches of subgrade soils underljdng exterior flatwork should be
presoaked to a minimum depth of 12 inches below slab subgrade. Concrete swales should be
designed in roadway or parking areas subject to concentiated surface mnoff.
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GeoLogic Associates
7.0 CONSTRUCTION OBSERVATION, LIMITATIONS, AND PLAN REVIEW
The conclusions and recommendations in this report are based in part upon data that were
obtained from a limited number of observations, site visits, excavations, samples, and tests. 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 reUed upon only if GLA has the opportunity to observe the subsurface conditions
during grading and constmction of the project, m order to confirm that our preliminary findings
are representative for the site. In addition, we recommend that this office have an opportunity to
review the final grading and foundation plans in order to provide additional site-specific
recommendations.
This report has not been prepared for use by parties or projects other than those named or
described above. It may not contain sufficient information for other parties or other purposes.
This report has been prepared in accordance with generally accepted geotechnical practices and
makes no other warranties, either express or implied, as to the professional advise or data
contained herein.
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GeoLogic Associates
P 8.0 REFERENCES
li
1^
1^1
Blake, Thomas F., 2004a, EQFAULT, Version 3.00, Deterministic Estimation of Peak
Acceleration from Digitized Faults.
J Blake, Thomas F., 2004b, FRISKSP, Version 4.00, Probabilistic Earthquake Hazard Analysis
Using Multiple Forms of Ground-Motion-Attenuation Relationships.
California Building Code, (CBC), 2001.
CDMG, 1996, Probabilistic Seismic Hazard Assessment for the State of California, Open-File
Report No. 96-08.
Excel, 2007, Site Development Plan, Sheets Cl and C2, CT06-16.
Garcia, A.W. and Houston, J.R., 1974, Tsunami Run-up Prediction for Southem California Coastal
Communities, USA in Tsunami Research Symposium 1974; Royal Society of New Zealand,
BuUetin 15.
Hart, E. W., and Bryant, W. A., 1997, Fault- Ruptiire Hazard Zones in California, Alquist-Priolo
Earthquake Fault Zonmg Act with Index to Earthquake Fault Zones Maps: CDMG Special
Publication 42.
lida, K., 1969, The Generation of Tsunami and the Focal Mechanism of Earthquakes in Tsunami
in the Pacific Ocean; Proceeding of the Intemational Symposium on Tsimamis and
Tsunami Research, University of Hawaii, East-West Center Press.
Intemational Conference of Building Officials, 1997, Uniform Building Code.
E Ishihara, K., 1985, "Stability of Natural Deposits during Earthquakes", Proceedings ofthe
Eleventh Intemational Conference of Soil Mechanics and Foimdation Engineering, A. A.
g Belkema Publishers, Rotterdam, Netherlands.
Ishihara, K. and Yoshimine, M., 1992, "Evaluation of Settlements in Sand Deposits FoUowing
Liquefaction of Sand Under Cyclic Stiesses", Soils and Foundations, Vol. 32, No. 1, pp.
173-188.
2 - 21 -
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GeoLogic Associates
Joy, J.W., 1968, Tsunamis and Their Occurrence Along the San Diego County Coast Prepared
for the Unified San Diego County Civil Defense and Disaster Organization: Westinghouse
Oceans Research Laboratory.
McCullough, 1985, Evaluating Tsunami Potential, in Evaluating Earthquake Hazards in the Los
Angeles Region: An Earth-Science Perspective, USGS Professional Paper 1360.
Southem Cahfomia Earthquake Center (SCEC), 1999, Recommended Procedures for
Implementation of DMG Special Publication 117, Guidelines for Analyzing and Mitigating
Liquefaction in California, March 1999.
Tan, S. S., and Kennedy, M. P., 1996, Geologic Maps of the Northwestern Part of San Diego
County, California: CDMG Open-File Report 96-02, Plate 1.
USC, 2005, website: http://www.usc.edu/dept/tsunamis/califomia/.
U. S. Geological Survey (USGS), 1986, 7 Vi- Minute Topographic Series, San Luis Rey, Original
1975, photorevised 1986, map scale 1:24,000.
U.S. Department of the Navy, 1969, Civil Engineering, DM-5.
USGS, 2005a, website: http://earthquake.usgs.gov/recenteqsww/Ouakes/usslav.htm.
USGS, 2005b, http://en.wikipedia.org/wiki/2004 Indian_Ocean_earthquake#Ouake_characteristics
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GeoLogic Associates
tum; 1,000-meter U T M giid zone 11
i>i.igage.cDm]
S Quads: San Luis ReyjCA EncinHas:
1000
REFERENCE: U.S.G.S. 7.5 Minute Topographic Series, San Luis Rey, 1968, Pliotorevised 1975.
FIGURE 1
N
i
VICINITY MAP
VIP PARTNERS
4509 ADAMS STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
GeoLogic Associates
Geologists, Hydrogeologis-ts, and Engineers
Draft Date Project No.
JGF 2/2007 2007-0020
REFERENCE: EXCEL, 2007.
SCALE: 1 INCH = APPROX. 30 FEET FIGURE 2
LEGEND
5
•4 APPROXIMATE LOCATION OF
EXPLORATORY BORING
APPROXIMATE LOCATION OF
CROSS SECTION (FIGURE 3)
N
i
BORING LOCATION MAP
VIP PARTNERS
4509 ADAMS STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
GeoLogic Associates
Geologists, Hydrogeotoglsts. and Engineers
Draft
JGF
Date
FEB 2007
Project No.
2007-0020
I BORING B-1
ROOF PATIO
'=50,00
GARAGE
FLOOR=8.00,
TD=36.5'
EXISTING GRADE
PROPOSED LOWEST FINISH FLOOR TD=11.5'
REFERENCE: EXCEL, 2007.
FOR CROSS SECTION LOCATION, SEE FIGURE 2.
SCALE:
1 INCH = APPROX. 14 FEET
AT 11 X 17 INCH FORMAT ONLY
1
LEGEND
APPROXIMATE LOCATION OF EXPLORATORY BORING WITH TOTAL DEPTH (TD)
^ *V« APPROXIMATE LOCATION OF GEOLOGIC CONTACT, QUIERIED WHERE UNCERTAIN
^ APPROXIMATE LOCATION OF SEEPAGE ENCOUNTERED DURING DRILLING
Af Fill Soils Qt Terrace Deposits
Qcol Colluvium Ts Santiago Formation
FIGURES
CROSS SECTION A-A'
VIP PARTNERS
4509 ADAMS STREET CONDOMINIUMS
CARLSBAD, CALIFORNIA
GeoLogic Associates
Draft Date
JGF FEB 2007
Project No.
2007-0020
RECOMMENDED EARTH PRESSURES
FOR SHORING
Anchor resistance behind this line
Tie-back
T (4' MSL)
Tie-Back Shoring Diagram
Neglect upper one foot of passive pressure except where concrete or pavement exists
Below groundwater table.
FIGURE 4
VIP PARTNERS
4509 ADAMS STREET
CARLSBAD, CALIFORNIA
SHORING DESIGN
GeoLogic Associates
Geologists, Hydrogeologists, and Engineers
DRAFT DATE JOBNA.
JGF MARCH 2007 2007-0020
APPENDIX A
BORING LOGS
GeoLogic Associates
Boring Log
BORING NO.: B-1
PAGE 1 OF 1
JOB NO.:
SITE LOCATION:
DRILUNG METHOD:
CONTRACTOR:
LOGGED BY:
2007-0020
ADAMS STREET, CARLSBAD, CA
8" 0 HOLLOW STEM AUGER
CAL PAC MOBIL B-53
T. PRIMAS
DATE STARTED: 2/16/2007
DATE FINISHED: 2/16/2007
ELEVATION: 34.5 FEET (EXCEL. 2007)
GW DEPTH;
CAVING DEPTH;
TOTAL DEPTH;
NA
NA
36.5 FEET
1 UJ 3 Si
o
(7)
UJ X
(J
o z
a. DESCRIPTION
105.7
123.8
8.8
10.3
123.6 10.1
20
18
68
38
32
44
51
40
75
BULK
2.5
1.4
2.5
1.4
1.4
1.4
2.5
1.4
BULK
1.4
10
11
--6
40
45
50
•10
ML TTEO
TWO INCHES OF ASPHALT OVER MODERATE BROWN (SYR
4/4) MOIST, STIF, CLAYEY SILT.
COLLUVIUM:
PALE YELLOWISH BROWN (10YR 6/2) MOIST. STIFF CLAYEY
SILT WITH CAUCHE VEINS.
TERRACE DEPOSITS:
DARK YELLOWISH ORANGE. MOIST. MEDIUM DENSE, RNE
SILTY SAND WITH TRACE OF CLAY.
SM SANTIAGO FORMATION:
YELLOWISH GRAY (5Y 7/2) MOIST, VERY DENSE, SILTY
SANDSTONE.
ML YELLOWISH GRAY (5 Y 7/2) MOIST, VERY DENSE. ClAYEY
SILTSrONL
•12
•13
•14
•15
•16
NOTES:
1. TOTAL DEPTH = 36.5 FEET.
2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A
30-INCH DROP.
3. NO GROUNDWATER ENCOUNTERED AT TIME OF
DRILUNG.
4. BORING BACKnU£D WITH BENTONITE ON 2/16/07.
The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring
and at the tinne of drilling. Subsurface conditions may differ at other locations and may change with the passage of time.
GeoLogic Associates
Boring Log
BORING NO.: B-2
PAGE: 1 OF 1
JOB NO
SITE LOCATION:
DRIUJNG METHOD:
CONTRACTOR
LOGGED BY:
2007-0020
ADAMS STREET. CARLSBAD. CA
8" 0 HOLLOW STEM AUGER
CAL PAC MOBIL B-53
T. PRIMAS
DATE STARTED: 2/16/2007 GW DEPTH;
DATE RNISHED: 2/16/2007 CAVING DEPTH;
ELEVATION: 35.0 FEET (EXCEL. 2007) TOTAL DEPTH;
NA
NA
16.5 FEET
H
o --^
i|
o
y I
a.
<
Sly
Ul
o
Si |i
65 u.
DESCRIPTION
62.5 6.6
126.1 8.5
29
22
36
36
41
BUU<
1.4
2.5
BUU<
1.4
2.5
BUU<
1.4
20
25
30
40
45
50
TOO
TWO INCHES OF ASPHALT OVER DARK REDDISH BROWN
(10YR 3/4) MOIST. LOOSE. SILTY SAND. TERRACE DEPOSITS:
DARK REDDISH BROWN (10YR 3/4) MEDIUM DENSE. RNE
SILTY SANDSTONE.
10
11
12
•13
•14
•15
•16
SANTIAGO FORMATION:
YEU.OWISH GRAY (5Y 7/2) MOIST. DENSE, RNE SILTY
SANDSTONE.
NOTES:
1. TOTAL DEPTH = 16.5 FEET.
2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A
30-INCH DROP.
3. NO GROUNDWATER ENCOUNTERED AT TIME OF
DRILUNG.
4. BORING BACKRUID WITH SOIL ON 2/16/07.
The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring
and at the time of drilling. Subsurface conditions may differ at other locations and may chonge with the passage of time.
GeoLogic Associates
Boring Log
BORING NO.: B-3
PAGE: 1 OF 1
JOB NO
SITE LOCATION;
DRILUNG METHOD;
CONTRACTOR;
LOGGED BY;
2007-0020
ADAMS STREET. CARLSBAD. CA
8" 0 HOU.OW STEM AUGER
CAL PAC MOBIL B-53
T. PRIMAS
DATE STARTED: 2/16/2007
DATE RNISHED: 2/16/2007
ELEVATION: 11.0 FEET (EXCEU 2007)
GW DEPTH;
CAVING DEPTH;
TOTAL DEPTH;
NA
NA
11.0 FEET
uj =>
O
UJ o z
0.
I
xtl
£li!
UJ
o
QO
Si
(oU.
DESCRIPTION
107.9
118.4
9.2
12.4
13
8
10
24
BUU<
2.5
1.4
2.5
1.4
2
3
4
15
20
25
30
35
40
45
50
SC Tiili
2.5 INCHES OF ASPHALT OVER DUSKY YELLOWISH BROWN
(10YR 2/2) MOIST. MEDIUM DENSE. RNE CLAYEY SAND.
SC COU.UVIUM:
DUSKY YEU.OWISH BROWN (10YR 2/2) MOIST. LOOSE.
RNE CLAYEY SAND.
10
11
12
13
14
15
16
SM SANTIAGO FORMATION:
YELLOWISH GRAY (5Y 7/2) MOIST. MEDIUM DENSE. RNE
SILTY SANDSTONE.
^
NOTES:
1. TOTAL DEPTH = 11.5 FEET.
2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A
30-INCH DROP.
3. NO GROUNDWATER ENCOUNTERED AT TIME OF
DRIUJNG; SEEPAGE AT 7.5 FEET.
4. BORING BACKRU£D WITH BENTONITE ON 2/16/07.
The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this boring
and at the time of drilling. Subsurface conditions may differ at other locations and may change with the passage of time.
GeoLogic Associates
Boring Log
BORING NO.: B-4
PAGE: 1 OF 1
JOB NO.
SITE LOCATION:
DRIUJNG METHOD;
CONTRACTOR;
LOGGED BY;
2007-0020
ADAMS SFREET. CARLSBAD. CA
8" 0 HOLLOW STEM AUGER
CAL PAC MOBIL B-53
T. PRIMAS
DATE STARTED: 2/16/2007 GW DEPTH;
DATE RNISHED: 2/16/2007 CAVING DEPTH;
ELEVATION: 13.0 FEET (EXCEL. 2007) TOTAL DEPTH;
NA
NA
16.5 FEET
II o
u) in
" Ul Ul _l
a. I
xb Eg
o
DESCRIPTION
4
4
6
31
BUU<
1.4
1.4
1.4
1.4
2
3
4
15
20
25
35
40
45
50
2.5 INCHES OF ASPHALT OVER DUSKY YELLOWISH BROWN
(10YR 2/2) MOIST. VERY LOOSE. RNE CLAYEY SAND.
COU.UVIUM:
DUSKY YELLOWISH BROWN (10YR 2/2) MOIST. VERY
LOOSE. RNE CLAYEY SAND.
SANTIAGO FORMATION:
YELLOWISH GRAY (5Y 7/2) MOIST. DENSE. RNE SILTY
SANDSTONE.
NOTES:
1. TOTAL DEPTH = 11.5 FEET.
2. SAMPLER DRIVEN BY A 140-POUND HAMMER WITH A
30-INCH DROP.
3. NO GROUNDWATER ENCOUNTERED AT TIME OF
DRIUJNG.
4. BORING BACKRUiD WITH BENTONITE ON 2/16/07.
•10
11
•12
•13
•14
•15
•16
The data presented on this log is a simplification of actual conditions encountered and applies only at the location of this twring
and at the time of drilling. Subsurface conditions may differ at other locations and may change with the passage of time.
APPENDIX B
LABORATORY TESTING PROCEDURES AND TEST RESULTS
APPENDIX B
LABORATORY TESTING PROCEDURES AND TEST RESULTS
Expansion Index Tests: The expansion potential of selected materials was evaluated by the
Expansion hidex Test, U.B.C. Standard No. 18-2 (ASTM D4829). Specimens are molded under a
given compactive energy to approximately the optimum moisture content and approximately 50
percent saturation or approximately 90 percent relative compaction. The prepared 1-inch thick by
4-inch diameter specimens are loaded to an equivalent 144 psf surcharge and are inundated with tap
water until volumetric equilibrium is reached. The results of these tests are presented below:
-Sample, Depth Sample Description Expansion
Index
Expansion
Potential*
-B-l/10,31'-33' Light olive gray fine to coarse sandy
clay to clay sand (Santiago Fm)
23 Low
-
B-2/4, 5'-7' Orange brown fine sandy clay
(Terrace Deposits)
32 Low
B-3/1,0-2' Dark gray fine to medium sand (Fill) 0 Very Low
* Based on the 1997 edition ofthe Uniform Building Code, prepared by the Intemational Conference of Building
Officials, (UBS, 1997/CBC, 2001).
Minimum Resistivitv and pH Tests: Minimum resistivity and pH tests were performed in general
accordance with California Test Method 643. The results are presented in the table below:
m
Sample, Depth pH Minimum Resistivity
(ohms-cm) Corrosion Potential**
-B-l/10,31'-33' 8.2 1,525 Very High
B-2/7, ll'-13' 7.6 680 Very High
m B-3/1, 0-2' 8.4 1,350 Very High
** per City of San Diego Program Design Guidelines for Consultants, 1992, and US Navy, 1969.
Direct Shear Testing: Relatively undisturbed samples fi-om the test pits were obtained in the
sandier strata and direct shear testing was performed in accordance with ASTM D 3080. The
results are presented as follows:
Sample Location Friction Angle (Degrees) Cohesion^sf)
B-1/4,7'-8' (Terrace Deposits) 37 400
C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Fiiial ReportWIP Partners Adams Report.doc
B-1/8,25'-26' (Santiago Formation) 38 700
Soluble Sulfates: The soluble sulfate contents of a selected sample were determined by California
Test Method 417. The test results are presented in the table below:
Sample, Depth Soluble Sulfate Content (ppm) Sulfate Exposure***
m B-l/10,31'-33' 74 Negligible
mm
B-2/7,11'-13' 428 Negligible
B-3/1, 0-2' 613 Negligible
*** Based on the 1997 edition ofthe Uniform Building Code, Table No. 19-A.4, prepared by the Intemational
Conference of Building Officials, (UBC, 1997/CBC, 2001).
"R"-Value: The resistance "R"-value was determined by the California Materials Method No. 301.
The selected sample was prepared and exudation pressure and "R"-value determined. The
graphically determined "R"-value at exudation pressure of 300 psi is reported.
Sample Location R-Value
B-2/4, 5'-7' 34
B-2/7,11'-13' 5
C:\Active\_Projects\2007\2007-0020 - Courtney Adams Condos\Final ReportWIP Partners Adams Report.doc
•R' VALUE CA 301
Project ViP Partners / Adams street
Sample B-2/4
Soil Type Orange Brown, F.M. Sandy Clay
Job No. 2002-017
By: LD
Date 3/1/2007
mm TEST SPECIMEN A B C Grain Size Distribution
m Compactor Air Pressure psi 160 55 80 Sieve As Rec'vd.
{%Pass.)
As Tested
(%Pass.)
mm Initial Moisture Content % 8.1 8.1 8.1 3"
m Water Added ml 60 80 70 21/2"
mm Moisture at Compaction % 13.5 15.3 14.4 2"
m Sample & Mold Weight gms 3146 3150 3147 11/2"
-Mold Weight gms 2114 2101 2106 1"
Net Sample Weight gms 1032 1049 1041 3/4"
Sample Height in. 2.47 2.531 2.502 1/2"
Dry Density pcf 111.5 108.9 110.2 3/8"
Pressure lbs 7170 2915 3960 #4
Exudation Pressure psi 571 232 315 #8
m Expansion Dial X 0.0001 31 10 20 #16
mm Expansion Pressure psf 134 43 87 #30
m Ph atlOOOIbs psi 28 50 39 #50
mm Ph at 2000lbs psi 57 117 85 #100
-Displacement turns 3.54 3.92 3.77 #200
R' Value 56 19 37 Sand Equivalent
m Corrected 'R' Value 56 19 37 (CTM 217)
FINAL "R" VALUE
By Exudation Pressure {@ 300 psi): 34
By Epansion Pressure 36
Tl= 5
GeoLogic Associates
'R' VALUE OA 301
Project VIP Partners / Adams street
Sample B-2/7
Soil Type Olive L. Brown, Clay (CH) / Sandy Clay
Job No. 2002-017
By: LD
Date 3/1/2007
TEST SPECIMEN A B C Grain Size Distribution
Compactor Air Pressure psi 30 40 30 Sieve As Rec'vd.
(%Pass.)
As Tested
(%Pass.)
Initial Moisture Content % 6.0 6.0 6.0 3"
Water Added ml 160 120 140 21/2"
-Moisture at Compaction % 20.1 16.6 18.4 2"
Sample & Mold Weight gms 3106 3187 3202 11/2"
mm Mold Weight gms 2104 2109 2108 1"
Net Sample Weight gms 1002 1078 1094 3/4"
Sample Height in. 2.518 2.628 2.71 1/2"
Dry Density pcf 100.4 106.6 103.3 3/8"
Pressure lbs 2650 6360 4300 #4
Exudation Pressure psi 211 506 342 #8
Expansion Dial x 0.0001 0 10 3 #16
Expansion Pressure psf 0 43 13 #30
-Ph atlOOOIbs psi 95 80 90 #50
Ph at 2000lbs psi 160+ 145 155 #100
m Displacement turns -3.93 4.8 #200
R' Value <5 6 2 Sand Equivalent
m Corrected 'R' Value <5 6 2 (CTM 217)
FINAL "R" VALUE
By Exudation Pressure (@ 300 psi): <5
By Epansion Pressure N/A
Tl= 5
GeoLogic Associates
Job No. 2007-020 DIRECT SHEAR TEST - ASTM D-3080 VIP Partners /Adams Street
peak shear strength strength at 1/4" displacement
4000
3750
3500
3250
3000
2750
.,2500
OT
_c2250
O)
c <D2000 i_ -I—'
CO
Jo 1750
0)
CO 1500
1250
1000
750
500
250
Sample
500 1000 1500 2000 2500
Normal Pressure (psf)
Strain Rate: 0.0042 in. / min.
3000 3500 4000
B-1/4
Normal Pressure (psf)
1000
2000
4000
Type Description
Undisturbed Sandy Clay
& Saturated
Drv Densitv (PCf) Initial Water Content i%)
123.8 10.3
Peak Shear Strength (psf) Ultimate Shear Strength (psf)
1130 @ 0.0600"
2140 (§) 0.0085"
3430(3)0.1050"
0= 400 psf
([)= 37 deg.
720
1380
2600
C = 100 psf
(t) = 32 deg.
GeoLogic Associates
Job No. 2007-020 DIRECT SHEAR TEST - ASTM D-3080 ViP Partners /Adams Street
4000
3750
3500
3250
3000
2750
.,2500
OT Q.
_c2250 +.* C3) c
<D2000
CO
1750
0)
CO 1500
1250
1000
750
500
250
Sample
-1/8
peak shear strength strength at 1/4" displacement
500 1000 1500 2000 2500
Normal Pressure (psf)
Strain Rate: 0.0042 in. / min.
3000 3500 4000
Type Description
Undisturbed Sandy Clay
& Saturated
Drv Densitv fpcf) Initial Water Content (%)
123.6 10.1
Normal Pressure (psf)
1000
2000
4000
Peak Shear Strength (psf) Ultimate Shear Strength (psf)
1460(3)0.0575"
2340 @ 0.0840"
3820 @ 0.1020"
0= 700 psf
(])= 38 deg.
760
1370
2690
C = 100 psf
(^ = 33 deg.
GeoLogic Associates
APPENDIX C
SEISMIC ANALYSIS
CALIFORNIA FAULT MAP
VIP Partners/Adams Street Condos
1100
1000
900 --
800 --
700 --
600 --
500
400
300 --
200 --
100 --
-100
-400 -300 -200 -100 0 100 200 300 400 500 600
75 --
50 --
25 --
0 --
-25
-50 --
CALIFORNL\ FAULT MAP
VIP Partners/Adams Street Condos
190 200 210 220 230 240 250 260 270 280 290 300 310
* EQFAULT *
* *
* Version 3.00 *
DETERMINISTIC ESTIMATION OF
PEAK ACCELERATION FROM DIGITIZED FAULTS
JOB NUMBER: 2007-0020
DATE: 02-22-2007
JOB NAME: VIP Partners/Adams Street Condos
CALCULATION NAME: Test Run Analysis
FAULT-DATA-FILE NAME: C:\Program Files\EQFAULTl\CGSFLTE_2004.DAT
SITE COORDINATES:
SITE LATITUDE: 33.14 4 9
SITE LONGITUDE: 117.3261
SEARCH RADIUS: 100 mi
ATTENUATION RELATION: 2) Boore et al. (1997) Horiz. - NEHRP C (520)
UNCERTAINTY (M=Median, S=Sigma) : M Niimber of Sigmas: 0.0
DISTANCE MEASURE: cd_2drp
SCOND: 0
Basement Depth: 5.00 km Campbell SSR: Campbell SHR:
COMPUTE PEAK HORIZONTAL ACCELERATION
FAULT-DATA FILE USED: C:\Program Files\EQFAULTl\CGSFLTE_2004.DAT
MINIMUM DEPTH VALUE (km): 0.0
EQFAULT SUMMARY
DETERMINISTIC SITE PARAMETERS
Page 1
ABBREVIATED
FAULT NAME
APPROXIMATE
DISTANCE
mi (km)
================================ ====. === ==== === ===== ====== ==== ====== ======
ROSE CANYON 5 • 0( 8 .1) 7 .2 0 .335 IX
NEWPORT-INGLEWOOD (Offshore) 6 .0 ( 9 .7) 7 .1 0 .288 IX
CORONADO BANK 21 • 1 { 33 .9) 7 6 0 .156 VIII
ELSINORE (TEMECULA) 24 .1 ( 38 .8) 6 8 0 .093 VII
ELSINORE (JULIAN) 24 .2 ( 38 .9) 7 1 0 .108 VII
ELSINORE (GLEN IVY) 34 .4 ( 55 .4) 6 8 0 .070 VI
SAN JOAQUIN HILLS 36 .2 ( 58 .2) 6 6 0 .074 VII
tttMl PALOS VERDES 36 8 ( 59 .2) 7 3 0 .087 VII
EARTHQUAKE VALLEY 43 1 ( 69 .4) 6 5 0 .051 VI
SAN JACINTO-ANZA 46 8 ( 75 .3) 1 7 2 0 .069 VI
m NEWPORT-INGLEWOOD (L.A.Basin) 47 0 ( 75 .7) 1 7 1 0 .065 VI
SAN JACINTO-SAN JACINTO VALLEY 47 5 ( 76 .4)1 6 9 1 0 .058 VI
.mm CHINO-CENTRAL AVE. (Elsinore) 48 0 ( 77 .2) i 6 7 1 0 .063 VI
SAN JACINTO-COYOTE CREEK | 52 0 ( 83 .7) 1 6 6 1 0 .046 VI
WHITTIER 1 52 2 ( 84 .0) 1 6. 8 1 0 .051 VI
ELSINORE (COYOTE MOUNTAIN) | 57 2 ( 92 .0) 1 6. 8 1 0 .048 VI
mm SAN JACINTO-SAN BERNARDINO | 60 5 ( 97 .3) 1 6. 7 1 0 .043 1 VI
m PUENTE HILLS BLIND THRUST | 62 4 ( 100 .5) j 7. 1 1 0 .063 1 VI
SAN JACINTO - BORREGO j 65 6 ( 105 . 6) 1 6. 6 1 0 .039 1 V
SAN ANDREAS - San Bernardino M-l| 66 1 ( 106 .4) 1 7. 5 1 0 062 1 VI
SAN ANDREAS - Whole M-la | 66. 1 ( 106 .4)1 8. 0 1 0 080 1 VII
m SAN ANDREAS - SB-Coach. M-lb-2 | 66. 1 ( 106 .4) 1 7. 7 1 0 068 1 VI
SAN ANDREAS - SB-Coach. M-2b | 66. 1 ( 106 .4)1 7. 7 1 0 068 1 VI
mm SAN JOSE 1 69. 0 ( 111 .1)1 6. 4 1 0 041 1 V
CUCAMONGA j 71. 1 ( 114 .5) 1 6. 9 1 0 052 1 VI
<m SIERRA MADRE | 71. 7 ( 115 .4) 1 7. 2 1 0 060 1 VI
PINTO MOUNTAIN | 72. 0 ( 115 .8) 1 7. 2 1 0 049 1 VI
SAN ANDREAS - Coachella M-lc-5 | 73. 1 { 117 .6) 1 7. 2 1 0 049 1 VI
m NORTH FRONTAL FAULT ZONE (West) | 75. 1 ( 120 9) 1 7. 2 1 0 058 j VI
BURNT MTN. | 76. 9 ( 123 7) 1 6. 5 1 0 032 1 V
•mm. UPPER ELYSIAN PARK BLIND THRUST | 77. 9 ( 125 4) 1 6. 4 1 0 037 1 V
CLEGHORN | 78. 2 ( 125 8) 1 6. 5 1 0 032 1 V
SAN ANDREAS - 1857 Rupture M-2a | 79. 7 ( 128 3) 1 7. 8 1 0. 062 1 VI
SAN ANDREAS - Cho-Moj M-lb-1 | 79. 7 ( 128 3) 1 7. 8 1 0. 062 1 VI
SAN ANDREAS - Mojave M-lc-3 | 79. 7 ( 128 3) 1 7. 4 1 0. 050 1 VI
m NORTH FRONTAL FAULT ZONE (East) | 80. 1 ( 128 9) 1 6. 7 1 0. 042 1 VI
EUREKA PEAK | 80. 1 ( 128 9) 1 6. 4 1 0. 030 1 V
•mm RAYMOND 1 80. 2 { 129 0) 1 6. 5 1 0. 038 1 V
CLAMSHELL-SAWPIT I 81. 1 ( 130 5) 1 6. 5 1 0. 038 1 V
m SUPERSTITION MTN. (San Jacinto) | 81. 9( 131. 8) 1 6. 6 1 0. 032 1 V
ESTIMATED MAX. EARTHQUAKE EVENT
MAXIMUM
EARTHQUAKE
MAG.(Mw)
PEAK
SITE
ACCEL.
EST. SITE
INTENSITY
MOD.MERC.
DETERMINISTIC SITE PARAMETERS
Page 2
APPROXIMATE
40 ABBREVIATED | DISTANCE MAXIMUM PEAK 1 EST. SITE
FAULT NAME | mi (km) EARTHQUAKE SITE 1 INTENSITY
MAG.(Mw) ACCEL, g 1 MOD.MERC.
••
VERDUGO 1 83.3( 134 . 0) 6.9 0.046 1 VI
HOLLYWOOD I 85.3( 137. 2) 6.4 0.034 1 V
<m ELMORE RANCH I 85.5 ( 137. 6) 6.6 0.031 1 V
•Mm SUPERSTITION HILLS (San Jacinto)| 86. 6 ( 139. 3) 6.6 0.031 1 V
Wm LANDERS 1 87.4 ( 140. 6) 7.3 0.045 1 VI
LAGUNA SALADA I 88.4 ( 142. 3) 7.0 0.038 1 V
HELENDALE - S. LOCKHARDT | 88.7 ( 142. 8) 7.3 0.044 1 VI
m SANTA MONICA j 89.5( 144. 0) 6.6 1 0.037 1 V
LENWOOD-LOCKHART-OLD WOMAN SPRGS| 92. 6 ( 149. 0) 7.5 1 0.047 1 VI
•mi MALIBU COAST I 92.8 ( 149. 4) 6.7 1 0.038 1 V
BRAWLEY SEISMIC ZONE | 94.7 ( 152. 4) 6.4 0.026 1 V
m JOHNSON VALLEY (Northern) j 95.1 ( 153. 0) 6.7 j 0.030 1 V
EMERSON So. - COPPER MTN. | 96.1 ( 154. 7) 7.0 1 0.035 1 V
<«• SIERRA MADRE (San Fernando) i 96.3( 154 . 9) 6.7 1 0.037 1 V
m NORTHRIDGE (E. Oak Ridge) | 96.5 ( 155. 3) 7.0 1 0.043 1 VI
SAN GABRIEL I 98.1( 157. 8) 7.2 1 0.039 1 V
ANACAPA-DUME I 98.2 { 158. 0) 7.5 1 0.055 1 VI
m -END OF SEARCH- 57 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS.
ESTIMATED MAX. EARTHQUAKE EVENT
THE ROSE CANYON FAULT IS CLOSEST TO THE SITE.
IT IS ABOUT 5.0 MILES (8.1 km) AWAY.
LARGEST MAXIMUM-EARTHQUAKE SITE ACCELERATION: 0.3354 g
m
PROBABILITY OF EXCEEDANCE
BOORE ET AL(1997) NEHRP C (520)1
100
25 yrs 50 yrs
75 yrs 100 yrs
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
Acceleration (g)
PROBABILITY OF EXCEEDANCE
BOORE ET AL(1997) NEHRP C (520)2
100
25 yrs 50 yrs
75 yrs 100 yrs
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
Acceleration (g)