HomeMy WebLinkAboutCT 01-13; LAGUNA POINT; REPORT OF GEOTECHNICAL INVESTIGATION; 1999-06-07June 7, 1999
_Geotechnics
Incorporated
RECEIVED
Principals:
Anthony F. Belfast
Michael P. Imbriglio
W. Lee Vanderhurst
MAY 26 2004 Architect Judson Pittam Project No. 0525-001-00
5658-11 Etiwanda Avenue D Document No. 9-0484 Tarzana, California 91356
Attention: Mr. Judson Pittam
SUBJECT: REPORT OF GEOTECHNICAL INVESTIGATION
Park Laguna Condominiums
Carlsbad, California
Dear Mr: Pittam:
The following report presents the findings, conclusions, and recommendations of our geotechnical
investigation of the subject site. It is our understanding that the proposed development is to consist
of a three story 10 unit condominium complex along with landscaped areas and associated parking.
In general, our findings indicate that the subject site is underlain by fill and Bay Point Formation
materials that are considered suitable to support the proposed structures, provided that the
recommended site preparation is performed. There were no unusual or special conditions apparent
in our investigation which would preclude development as planned.
1.0 PURPOSE AND SCOPE OF WORK
The purpose of our investigation was to evaluate the existing apparent geotechnical conditions at the
site as they relate to the proposed improvements, and to make recommendations regarding the
geotechnical aspects of site preparation, grading, foundation design, on-grade slabs, retaining walls,
and pavements. The recommendations contained herein are based on a surface reconnaissance,
subsurface explorations, laboratory testing, engineering evaluations, and professional experience in
the general site area. Our scope of work was limited to:
.9245 Activity Rd., Ste. 103 • San Diego, California 92126
Phone-(614) 536-1000 • Fax 6+9) 536-8311
ARCHITECT JUDSON PITTAM PROJECT NO. 0525-001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 2
Review of available literature related to general geologic conditions.
S Subsurface explorations consisting of drilling eight borings with a truck mounted 8-inch
diameter hollow stem flight auger. Relatively undisturbed, disturbed, and bulk samples were
collected for laboratory testing during our field explorations.
Laboratory testing of selected samples collected during the subsurface explorations to assist
in characterizing soil properties and assessing pertinent engineering properties.
Development of recommendations for site preparation, earthwork construction, remedial
earthwork, foundation design, on-grade slabs, earth retaining structures, and asphalt and
concrete pavement design.
S Assessment of general seismic conditions and geologic hazards affecting.the area, and their
likely impact on the project.
Preparation of this report.
2.0 SITE DESCRIPTION
The subject site is located on the southeast corner at the intersection of State Street and Laguna Drive
in Carlsbad, California, as shown on the Site Location Map, Figure 1. The site was previously
developed, however, there .are no structures currently at the site. The site is overlain with old asphalt
paving and gravel, except for concrete paving on the southeast corner. A retaining wall having a
maximum height of about 5'/2 feet is located on the northwest corner of the site. Current site
elevations vary from about 40 feet above mean sea level (MSL) at the northwest corner to about 42
feet MSL at the southeast corner.
An underground fuel storage tank was reportedly located on the northwest corner of the site. It is
our understanding that the storage tank was removed and that an environmental report was issued
at completion of the removal and associated cleanup.
Geotechnics Incorporated
ADAPTED FROM THE 1998
THOMAS BROTHERS GUIDE
AwAhl Geotechnjcs
mulabb Incorporated
1 Inch to 2400 Feet
o .25 . .5 .75 1.0
SITE LOCATION MAP
Park Laguna Condominiums
Architect Judson Pittam
Project No. 0525-001-00
Document No. 9-0484
FIGURE 1
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ARCHITECT JUDSON PITTAIvI PROJECT NO. 0525-001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 3
3.0 PROPOSED DEVELOPMENT
It is our understanding that the proposed development will consist of a three-story 10 unit
condominium complex with landscaped areas and associated parking. We anticipate that wood
framing with conventional slabs-on-grade and shallow foundations will be used. The proposed
buildings will be constructed at approximate current elevations. Asphalt concrete and Portland
cement concrete paving is anticipated in the proposed parking lot. The site layout, with the proposed
construction, is shown in relation to our exploratory borings on the Site Plan, Figure 2.
4.0 GEOLOGY AND SUBSURFACE CONDITIONS
Based on published geological maps and reports, and our borings, the site is underlain by topsoil,
fill and terrace deposits, specifically, the Bay Point Formation. Eocene age Santiago Formation was
encountered in one boring, below elevation 25 feet. The subsurface conditions observed during our
field explorations are described in the logs of borings presented in Appendix B. The approximate
locations of the exploratory borings drilled for this investigation are shown on Figure 2. A
description of the subsurface materials encountered during our investigation follows.
4.1 Santiago Formation
The Santiago Formation was encountered in Boring B-8 below elevation 24 feet (17 feet
below existing grade). The formation typically consists of very dense silty fine to medium
grained sandstone with interbedded claystone. The Santiago Formation will not likely be
exposed during development of the site.
4.2 Bay Point Formation
The Quaternary age Bay Point Formation underlies the entire site at depth and was
encountered in most of the borings at a depth of about 2 to 12 feet. The Bay Point Formation
was observed to consists of sand, clayey sand and sandy clay. The sand was poorly graded,
orangish brown to gray in color, medium to coarse grained and medium dense to very dense.
The clayey sand was orangish brown, medium to coarse grained, dense to very dense. A
Geotechnics Incorporated
ARCHITECT JUDSON PIT-TAM PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 4
layer of sandy clay was observed in one of our borings. The sandy clay was oli
v
e
g
r
a
y
w
i
t
h
a high plasticity, and was observed to be firm.
43 Topsoil
Topsoil was encountered in four of our borings below the old asphalt concre
t
e
a
n
d
g
r
a
v
e
l
.
The topsoil consisted of brown to dark brown poorly graded sand which was fine
t
o
m
e
d
i
u
m
grained and loose to medium dense.
4.4 Fill
Fill soils were encountered during our investigation and consisted of clayey sand
a
n
d
s
a
n
d
and extended to a depth of about 17 feet below existing grade. The sand a
n
d
c
l
a
y
e
y
s
a
n
d
were brown to orangish brown, fine to medium grained, and dense. Some g
r
a
v
e
l
s
a
n
d
cobbles were encountered in our borings. The fill soils are derived from undergr
o
u
n
d
t
a
n
k
removal activities as well as previous undocumented fill activities.
Black staining was observed in some of the fill materials in our borings. Addi
t
i
o
n
a
l
l
y
,
hydrocarbon odor was observed in boring eight. The odor was observed after co
m
p
l
e
t
i
o
n
of the boring, prior to backfill.
4.5 Groundwater
Groundwater was encountered in two of our borings at a depth of about 1 7Y2 to 18 f
e
e
t
b
e
l
o
w
existing grade. The groundwater is likely perched above the contact between t
h
e
B
a
y
P
o
i
n
t
and Santiago Formations. This is a typical condition throughout the Carlsba
d
a
r
e
a
.
T
h
e
perched groundwater is presently too deep to affect the proposed development.
C
h
a
n
g
e
s
i
n
rainfall, irrigation, site drainage or leaks in a utility line could cause the ground
w
a
t
e
r
l
e
v
e
l
to fluctuate. It should be recognized that excessive irrigation on the project site
c
o
u
l
d
a
l
s
o
result in increases to the existing perched groundwater at some future d
a
t
e
.
S
i
n
c
e
t
h
e
prediction of the location of such conditions is not possible, they are typic
a
l
l
y
m
i
t
i
g
a
t
e
d
i
f
and when they occur.
Geotechnics Incorporated
r
ARCHITECT JUDSON PITTAM PROJECT NO. 0525-001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 5
5.0 GEOLOGIC HAZARDS AND SEISMICITY
5.1 Geologic Hazards
The subject site is not located within an area previously known for geologic hazard
s
,
- including active faulting, nor was evidence of past soil failures or faulting noted in our
investigation.
5.2 Seismicity and Faulting
The nearest known active fault is the Rose Canyon fault zone, located approximately4 miles
west of the site. No faults were encountered during our exploration of the site.
Active faults within 100km of the site are shown in the Fault Location Map, Figure 3. Table
1 presents the estimated peak ground accelerations for the site from regionally active faults
based on the distance between the site and the active fault, the maximum credible a
n
d
probable event associated with each fault, and published distance attenuation curves. In our
opinion, the most significant credible seismic event with respect to the subject site would be
a 7.0 magnitude event on the Rose Canyon fault zone, which would result in an estimated
peak ground acceleration of 0.42g. The most significant probable seismic event would be
a magnitude 6.4 earthquake along the Rose Canyon fault zone resulting in anestimatedpea
k
horizontal ground acceleration of approximately 0.36g. Design of structures should comply
with the requirements of the governing jurisdictions, building codes and standard practices
of the Association of Structural Engineers of California. Surface rupturing due to active
faulting is considered to have a low potential, due to the distance from known, active fa
u
l
t
traces.
5.3 Liquefaction and Dynamic Settlement
Soil liquefaction is typically associated with loose, cohesionless sands or silts below
groundwater. Given the relatively dense nature of the subsurface materials, the potential for
liquefaction to occur at the site is considered remote. Accordingly, the potential for dynamic
settlement to occur at the site is also considered remote.
Geotechnics Incorporated
0 10 20
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KILOMETERS CUCAMONGA FAULT
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Modified from Anderson, Rockwell, Agnew, 1,989
eotechnjcs
Incorporated
FAULT LOCATION MAP Project No. 0525-001-00
Park Laguna Condominiums Document No. 9-0484 Architect Judson Pittam FIGURE 3
FAULT'
DISTANCE
TO SITE
[MILES]
MAXIMUM CREDIBLE EVENT MAXIMUM PROBABLE EVENT
MOMENT
MAGNITUDE
PEAK HORIZ.
ACCEL.3 [g]
MOMENT
MAGNITUDE
PEAK HORIZ.
ACCEL.3 [g]
Coronado Banks 1.8.0 7.7 0.22 6.1 0.09 Elsinore 25.0 7.5 0.15 7.3 0.13
La Nacion 37.0 6.8 0.06 6.5 0.05 Rose Canyon 4.0 7.0 0.42 6.4 0.36 San Clemente 48.0 7.3 0.07 6.6 0.04 San Diego Trough 25.0 7.7 0.17 6.1 0.06 San Jacinto 49.0 7.5 0.07 6.6 0.04
Fault activity determined by CDMG (1992), Wesnousky (1986), and Jennings (1975).
Magnitudes modified from Mualchin, Jones (1992), Anderson, Rockwell, Agnew (1989), and Wesnousky (1986).
Peak horizontal accelerations: Idriss, Rock Site (1991).
Geotechnics
i=~~Incorporated
REGIONAL SEISMICITY
Park Laguna Condominiums
Architect Judson Pittam
Project Number 0525-001-00
Document Number 9-0484
TABLE I
ARCHITECT JUDSON PITTAM
PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 6
5.4 Landslides and Lateral Spreads
Evidence of ancient landslides at the site was not found. Recommendations are provi
d
e
d
i
n
the following sections of the report which will help to reduce the potential for future
s
l
o
p
e
instabilities. These recommendations focus on irrigation control and landscap
e
p
l
a
n
t
i
n
g
.
5.5 Tsunamis, Seiches, Earthquake Induced Flooding
The distance between the subject site and the coast, and the site's elevation abo
v
e
s
e
a
l
e
v
e
l
,
preclude damage due to seismically induced waves (tsunamis). Nearby bodies o
f
w
a
t
e
r
o
f
significantsize were not noted during this investigation, and accordingly, earthquake i
n
d
u
c
e
d
flooding is not anticipated to be a potential hazard.
Geotechnics Incorporated
ARCHITECT JUDSON PITAM PROJECT NO. 0525-001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 7
6.0 CONCLUSIONS
Based on the results of this investigation, it is our opinion that the proposed development is fea
s
i
b
l
e
from a geotechnical standpoint provided the following recommendations and accepted buildi
n
g
codes are followed. Some geotechnical constraints exist which require special design consideration
in order to decrease the likelihood of distress to the proposed improvements. The main geo
t
e
c
h
n
i
c
a
l
concerns at the site are the existence of undocumented fill and a transition from fill to formatio
n
a
l
materials. Geotechnical considerations for the design and construction of the project include
t
h
e
following:
There are no known active faults underlying the project site. The most likely seismic hazards
at the site would be associated with significant ground shaking from an event centered within
the Rose Canyon Fault Zone.
S The on-site topsoil materials and the existing fill materials, in their present state, are not
suitable for improvement areas. We recommend that these materials be removed, reworke
d
,
and placed as compacted fill.
The on-site fill and formational materials are, in general, suitable for re-use in compacted
fills. Any trash, demolition debris, or organic material encountered is considered unsuitable
for re-use in compacted fills. Clays having an Expansion Index greater than 20 are n
o
t
suitable for placement within the upper 5 feet of finished grade.
The site contains a transition from medium dense fill to very dense formational materials.
Transitions below foundations and slabs are not recommended due to the different settlement
characteristics of the materials, and the resulting potential for differential movements.
Consequently, we recommend that the cut portion of the building pads be excavated and
replaced as compacted fill.
Geotechnics Incorporated
ARCHITECT JUDSON PI11TAM PROJECT NO. 0525-001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 8
7.0 RECOMMENDATIONS
The remainder of this report presents recommendations regarding earthwork constructionand desig
n
of foundations, on-grade slabs, retaining walls, and pavements. These recommendations are based
on empirical and analytical methods typical of the standard of practice in southern California. If
these recommendations appear not to cover any specific feature of the project, please contac
t
o
u
r
office for additions or revisions to the recommendations.
7.1 Plan Review
We recommend that foundation and grading plans be reviewed by Geotechnics Incorporated
prior to plan finalization to evaluate conformance with the intent of the recommendations of
this report. Significant changes in the location of the proposed structures may require
additional geotecimical evaluation.
7.2 Excavation and Grading Observation
Foundation excavations and site grading should be observed by Geotechnics Incorporated.
During grading, Geotechnics Incorporated should provide observation and testing services
continuously. Such observations are considered essential to identify field conditions that
differ from those anticipated by the geotechnical investigation, to adjust designs to actual
field conditions, and to determine that the grading is accomplished in general accordance
with the recommendations of this report. Recommendations presented in this report are
contingent upon Geotechnics Incorporated performing such services. Our personnel should
perform sufficient testing of fill during grading to support our professional opinion as to
compliance with compaction recommendations.
(nt'hni'c nrr',tprl
ARCHITECT JUDSON PLUAM
PROJECT NO. 0525.001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 9
7.3 Earthwork
Grading and earthwork should be conducted in accordance with the Grading Ordinance of
the City of Carlsbad and Appendix Chapter 33 of the Uniform Building Code. The
following recommendations are provided regarding specific aspects of the proposed
earthwork construction. These recommendations should be considered subject to revision
based on field conditions observed by the geotechnical consultant during grading.
7.3.1 General
Site preparation should include the removal of deleterious materials, existing
structures or other improvements from areas to be subjected to fill or structural loads.
Deleterious materials include vegetation, trash, construction debris, and rock
fragments with greatest dimensions in excess of 6 inches. Existing subsurface
utilities that are to be abandoned should be removed and the trenches backfilled and
compacted as described in Section 7.4.
7.3.2 Site Preparation
To reduce the potential for adverse settlement beneath the proposed improvement
areas, we recommend that the existing topsoil and fill materials be removed to expose
undisturbed formational materials. Based on our borings, the depth of removals is
anticipated to be on the order of approximately 2 to 3
Meet below current grades for
the topsoil and approximately 17 feet below current grade for the undocumented fills.
The over-excavated areas should extend horizontally at least five feet beyond the
building perimeter. The excavated soils should then be replaced with fill material
consisting of on-site or imported non-expansive soil with an expansion index less
than 20.
After making the recommended removals and prior to fill placement, the exposed
ground surface should be scarified to a depth of approximately 12 inches, brought to
approximately optimum moisture content as defined by ASTM D1557, and
ARCHITECT JUDSON PITTAM PROJECT NO. 0525-001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 10
compacted to 90 percent relative compaction compared to the maximum density as
defined by ASTM D1557.
A transition from fill to formational materials exist on the northwest corner of the
site, see Figure 2 for approximate location of transition line. Transitions below
foundations and slabs are not recommended due to the different settlement
characteristics of the materials, and the resultingpotential for differential movements.
For structures which have this transition, we recommend that the formational
materials of the building pad be over-excavated to minimum depth of 9 feet below
proposed finish grade elevation. The over-excavated portion of the pad should then
be brought back to finish grade with compacted fill as discussed in Section 7.4. Note
that the over-excavation envelope should extend a minimum of 5 feet beyond the
proposed building area. The intent of this recommendation is to provide a compacted
fill mat below the proposed structure with a minimum thickness of 9 feet. The lateral
extent of the remedial excavations for the cut/fill transition should be determined
during grading based on observations made by the geotechnical consultant.
As an alternative to over-excavation of the building pad, pier or other deep
foundation systems may be used for foundations within the fill materials. The
foundations should extend down to formational materials, approximately 17 feet
based on the borings. Geotechnics should be contacted to provide additional
foundation recommendations if deep foundations are used.
7.3.3 Temporary Excavations
Temporary excavations in fill should be inclined no steeper than 1:1 for heights up
to 10 feet. Temporary excavations within the formational material should be inclined
no steeper than 1/4:l for heights up to 10 feet. Geotechnics Incorporated should be
notified if deeper temporary excavations are required. Temporary excavations that
encounter seepage or other potentially adverse conditions should be evaluated by the
geotechnical consultant during grading. Remedial measures may include shoring or
reducing slope inclinations. All excavations should conform with Cal-OSHA
guidelines.
Geotechnics Incorporated
ARCHITECT JUDSON PITTAM
PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 11
7.4 Fill Compaction
All fill and backfill to be placed in association with site devel
o
p
m
e
n
t
s
h
o
u
l
d
b
e
accomplished at slightly over optimum moisture conditions using equ
i
p
m
e
n
t
t
h
a
t
i
s
c
a
p
a
b
l
e
of producing a uniform compacted product. The minimu
m
r
e
l
a
t
i
v
e
c
o
m
p
a
c
t
i
o
n
recommended for fill and backfill is 90 percent of maximum dry
d
e
n
s
i
t
y
b
a
s
e
d
o
n
A
S
T
M
D1557 guidelines. Prior to paving, the soil within the upper 12 inches of pave
m
e
n
t
s
u
b
g
r
a
d
e
should be scarified, moisture conditioned, and be compacted to at le
a
s
t
95 percent relative compaction based on ASTM D1557 guidelines. Sufficient observation and testing should
be performed by Geotechnics Incorporated so that an opinion can be
r
e
n
d
e
r
e
d
a
s
t
o
t
h
e
compaction achieved.
Imported fill sources, if needed, should be observed prior to ha
u
l
i
n
g
o
n
t
o
t
h
e
s
i
t
e
t
o
determine the suitability for use. Representative samples of impo
r
t
e
d
m
a
t
e
r
i
a
l
s
a
n
d
o
n
-
s
i
t
e
soils should be tested by Geotechnics Incorporated to evaluate their
a
p
p
r
o
p
r
i
a
t
e
e
n
g
i
n
e
e
r
i
n
g
properties for the planned use. Imported fill soils should have an Ex
p
a
n
s
i
o
n
I
n
d
e
x
o
f
n
o
more than 20 based on ASTM D 4829 guidelines.
-
During grading operations, soil types other than those analyzed in t
h
e
g
e
o
t
e
c
h
n
i
c
a
l
r
e
p
o
r
t
may be encountered by the contractor. Geotechnics Incorporated sh
o
u
l
d
b
e
n
o
t
i
f
i
e
d
t
o
evaluate the suitability of these soils for use as fill and as finish gr
a
d
e
s
o
i
l
s
.
7.5 Slopes
All slopes should be constructed at inclinations of 2:1 (horizontal to ver
t
i
c
a
l
)
o
r
f
l
a
t
t
e
r
.
T
h
e
surficial stability of slopes may be enhanced by providing go
o
d
s
i
t
e
d
r
a
i
n
a
g
e
.
T
h
e
s
i
t
e
should be graded so that water from the surrounding areas is not al
l
o
w
e
d
t
o
f
l
o
w
o
v
e
r
t
h
e
t
o
p
of the slope. Diversion structures should be provided where n
e
c
e
s
s
a
r
y
.
S
u
r
f
a
c
e
r
u
n
o
f
f
should be confined to gunite-lined swales or other appropriate devi
c
e
s
t
o
r
e
d
u
c
e
t
h
e
p
o
t
e
n
t
i
a
l
for erosion. It is recommended that slopes be planted with vegetati
o
n
t
h
a
t
w
i
l
l
i
n
c
r
e
a
s
e
t
h
e
i
r
stability. Ice plant is generally not recommended. We recommen
d
t
h
a
t
v
e
g
e
t
a
t
i
o
n
i
n
c
l
u
d
e
woody plants, along with ground cover. All plants should be adapte
d
f
o
r
g
r
o
w
t
h
i
n
s
e
m
i
a
r
i
d
Geotechnics Incorporated
ARCHITECT JUDSON PITTAM
PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 12
climates with little or no irrigation. A landscape architect sho
u
l
d
b
e
c
o
n
s
u
l
t
e
d
i
n
o
r
d
e
r
t
o
develop a specific planting palate suitable for slope stabilization.
7.6 Surface Drainage
Foundation and slab performance depends greatly on how well th
e
r
u
n
o
f
f
w
a
t
e
r
s
d
r
a
i
n
f
r
o
m
the site. This is true both during construction and over the
e
n
t
i
r
e
l
i
f
e
o
f
t
h
e
s
t
r
u
c
t
u
r
e
.
T
h
e
ground surface around structures should be graded so that w
a
t
e
r
f
l
o
w
s
r
a
p
i
d
l
y
a
w
a
y
f
r
o
m
t
h
e
'
structures without ponding. The surface gradient needed
t
o
a
c
h
i
e
v
e
t
h
i
s
d
e
p
e
n
d
s
o
n
t
h
e
prevailing landscape. In general, we recommend that paveme
n
t
a
n
d
l
a
w
n
a
r
e
a
s
w
i
t
h
i
n
f
i
v
e
feet of buildings slope away at gradients of at least two perce
n
t
.
D
e
n
s
e
l
y
v
e
g
e
t
a
t
e
d
a
r
e
a
s
should have minimum gradients of at least five percent awa
y
f
r
o
m
b
u
i
l
d
i
n
g
s
i
n
t
h
e
f
i
r
s
t
f
i
v
e
feet. Densely vegetated areas are considered those in which
t
h
e
p
l
a
n
t
i
n
g
t
y
p
e
a
n
d
s
p
a
c
i
n
g
is such that the flow of water is impeded.
Planters should be built so that water from them will not see
p
i
n
t
o
t
h
e
f
o
u
n
d
a
t
i
o
n
,
s
l
a
b
,
o
r
pavement areas. Roof drainage should be channeled by pipe to
s
t
o
r
m
d
r
a
i
n
s
,
o
r
d
i
s
c
h
a
r
g
e
at least 10 feet from building lines. Site irrigation shou
l
d
b
e
l
i
m
i
t
e
d
t
o
t
h
e
m
i
n
i
m
u
m
necessary to sustain landscaping plants. Should excessive irrig
a
t
i
o
n
,
s
u
r
f
a
c
e
w
a
t
e
r
i
n
t
r
u
s
i
o
n
,
water line breaks, or unusually high rainfall occur, saturated zon
e
s
o
r
"
p
e
r
c
h
e
d
"
g
r
o
u
n
d
w
a
t
e
r
may develop in the underlying soils.
7.7 Foundation Recommendations
These recommendations are considered generally consistent
w
i
t
h
m
e
t
h
o
d
s
t
y
p
i
c
a
l
l
y
u
s
e
d
i
n
southern California. Other alternatives may be available. The
f
o
u
n
d
a
t
i
o
n
r
e
c
o
m
m
e
n
d
a
t
i
o
n
s
contained herein should not be considered to preclude more rest
r
i
c
t
i
v
e
c
r
i
t
e
r
i
a
o
f
g
o
v
e
r
n
i
n
g
agencies or by the structural engineer. The design of the fou
n
d
a
t
i
o
n
s
y
s
t
e
m
s
h
o
u
l
d
b
e
performed by the project structural engineer, incorporatin
g
t
h
e
g
e
o
t
è
c
h
n
i
c
a
l
p
a
r
a
m
e
t
e
r
s
described in the following sections.
Geotechnics Incorporated
ARCHITECT JUDSON PITTAM
PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 13
7.7.1 Bearing Capacity
The following design parameters assume that the foundations are underlain entirely
by compacted fill with a low expansion potential prepared as recommended in
Section 7.3.2.
Allowable Soil Bearing: 2,000 psf (allow a one-third increase for short-
term wind or seismic loads).
Minimum Footing Width: 18 inches.
Minimum Footing Depth: 24 inches below lowest adjacent soil grade.
Minimum Reinforcement: Two No. 5 bars at both top and bottom in
continuous footings.
Settlement: Total and differential settlement value of Y2-
inch over a distance of 40 feet.
7.7.2 Site Seismic Factors
Based on the subsurface conditions at the site, the following site seismic parameters
may be used in the design of the proposed structures. The values are derived from
Tables 16-I through 16-U of the 1997 Uniform Building Code.
Seismic Zone Factor, Z 0.4
Soil Profile Type, S Sc Seismic Coefficient, Ca 0.40Na Seismic Coefficient, C,, 0.56N,, Near Source Factor, Na 1.0
Near Source Factor, N 1.15 Seismic Source Type B
/
Geotechnics Incorporated
ARCHITECT JUDSON PITTAM PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 14
7.7.3 Lateral Loads
Lateral loads against structures may be resisted by friction between the bott
o
m
o
f
footings and slabs and the supporting soil, as well as passive pressure fro
m
t
h
e
portion of vertical foundation members embedded into compacted fill. A
c
o
e
f
f
i
c
i
e
n
t
of friction of 0.4, and a passive pressure of 350 lbs/ft3 is recommended.
7.7.4 Slope Setback
Foundations setbacks should conform with UBC Figure 18-I-1. As a minimu
m
,
t
h
e
foundations for all structures should be setback from any descending slo
p
e
a
t
l
e
a
s
t
8 feet. The setback should be measured horizontally from the outside bot
t
o
m
e
d
g
e
of the footing to the slope face. The horizontal setback can be reduced by deep
e
n
i
n
g
the foundation to achieve the recommended setback distance projected
f
r
o
m
t
h
e
footing bottom to the face of the slope. It should be recognized that the out
e
r
f
e
w
feet of all slopes are susceptible to gradual downslope movements due to slope cr
e
e
p
.
This creep can affect hardscape such as concrete slabs. We recom
m
e
n
d
t
h
a
t
settlement sensitive structures including concrete slabs not be constructed
w
i
t
h
i
n
5 feet of the slope toe without a specific review by Geotechriics Incorporated.
7.8 On-Grade Slabs
Conventional building slabs should be supported by compacted fill a
s
p
r
e
v
i
o
u
s
l
y
recommended. Slabs should be designed for the anticipated loading. If an ela
s
t
i
c
d
e
s
i
g
n
i
s
used, a modulus of subgrade reaction of 150 lbs/in3 should be suitable. As a minimum, slabs
should be at least 5 inches in thickness and be reinforced as recommended by the structural
engineer, but at least No. 3 rebars on 24 inch centers, each way, or equival
e
n
t
w
e
l
d
e
d
w
i
r
e
fabric.
Geotechnics Incorporated
ARCHITECT JUDSON PITTAM
PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 15
7.9 Moisture Protection for Slabs
Concrete slabs constructed on soil ultimately cause the moisture content t
o
r
i
s
e
i
n
t
h
e
underlying soil. This results from continued capillary rise and the termination
o
f
n
o
r
m
a
l
evapotranspiration. Because normal concrete is permeable, the moisture will e
v
e
n
t
u
a
l
l
y
penetrate the slab unless some protection is provided. Excessive moisture may
c
a
u
s
e
mildewed carpets, lifting or discoloration of floor tile, or similar problems. The amo
u
n
t
o
f
moisture transmitted through the slab can be controlled by the use of vario
u
s
m
o
i
s
t
u
r
e
barriers.
To decrease the likelihood of problems related to damp slabs, suitable moisture prot
e
c
t
i
o
n
measures should be used where moisture sensitive floor coverings or other fac
t
o
r
s
w
a
r
r
a
n
t
.
A commonly used moisture protection consists of about 4 inches of clean sand
c
o
v
e
r
e
d
b
y
"visqueen" plastic sheeting. In addition, 2 inches of sand are placed over the pl
a
s
t
i
c
t
o
decrease concrete curing problems associated with placing concrete di
r
e
c
t
l
y
o
n
a
n
impermeable membrane. However, it has been our experience that such sy
s
t
e
m
s
w
i
l
l
transmit from approximately 6 to 12 pounds of moisture per 1000 square feet per
d
a
y
.
T
h
i
s
may be excessive for some applications.
If more moisture protection is needed, Geotechnics Incorporated should be contacte
d
t
o
a
s
s
i
s
t
the architect in the design of the under-slab system. The project architect should revi
e
w
t
h
e
moisture requirements of the proposed flooring system and incorporate an appropriat
e
l
e
v
e
l
of moisture protection as part of the floor covering design. This may include w
a
t
e
r
p
r
o
o
f
i
n
g
the slab.
7.10 Exterior Slabs
Exterior slabs should be at least 5 inches thick, and should be reinforced with at least No. 3
rebars on 18 inch centers, each way, or alternatively 6"x6"xW2.9xW2.9 weld
e
d
w
i
r
e
f
a
b
r
i
c
(WWF) placed at mid-height. Crack control joints should be placed on a maximu
m
o
f
1
0
foot centers, each way, for slabs, and 5 foot centers for sidewalks.
Geotechnics Incorporated
ARCHITECT JUDSON PITTAM
PROJECT NO. 0525-001-00 JUNE 7, 1999
. DOCUMENT NO. 9-0484
PAGE 16
7.11 Expansive Soils
The soils observed during our investigation consisted primarily of sand and clayey sand.
Laboratory testing of representative samples indicates that these soils have a very low
expansion potential, based on UBC criteria. Figure C-3 in the appendix summariz
e
s
t
h
e
expansion index test results.
7.12 Soil Corrosivity
A soil sample was tested for water-soluble sulfate content in general accordance wi
t
h
t
h
e
Standard Method for Evaluation of Waste Water Test SMEWW450OSO4E, which is
conducted in general conformance with EPA Test Method 375.4. The test results are
reported in Appendix C in terms of the percentage by weight of the water soluble sulfate in
the soil. The project design engineer may use these test results in conjunction with Table
1
9
-
A-4 of the 1997 UBC in order to specify a suitable cement type, water cement ratio, an
d
minimum compressive strength for concrete used on site which will be in direct contact with
soil, including all foundations and slabs. However, the sulfate content tests results pres
e
n
t
e
d
in Appendix C represent the existing soil conditions at the site. It should be noted
t
h
a
t
soluble sulfate in the irrigation water supply, and/or the use of fertilizer may cause the sulfate
content in the surficial soils to increase with time. This may result in a higher sulfate
exposure than that indicated by the test results reported herein. Studies have shown th
a
t
t
h
e
use of improved cements in the concrete, and a low water-cement ratio will increase
t
h
e
resistance of the concrete to sulfate exposure.
A soil sample was tested for pH and resistivity in general accordance with CALTRAN
S
T
e
s
t
Method 643. Based on the resistivity test results, the on-site materials appear to be corrosive
to ferrous metals. A corrosion consultant should be contacted to provide corrosion co
n
t
r
o
l
recommendations.
7.13 Earth Retaining Structures
Backfilling retaining walls with highly expansive soil can increase lateral pressures well
beyond normal active or at-ret pressures. We recommend that retaining walls be bac
k
f
i
l
l
e
d
ARCHITECT JUDSON PITTAM PROJECT NO. 0525.001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 17
with soil having an expansion index of 20 or less. The backfill area should include the zone
defined by a 1:1 sloping plane, extending from the base of the wall. Retaining wall backfill
should be compacted to at least 90 percent relative compaction, based on ASTM D1557.
Backfill should not be placed until walls have achieved adequate structural strength. Heavy
compaction equipment which could cause distress to the walls should not be used.
For cantilever retaining walls, where the backfill is level or nearly level, an active earth
pressure approximated by an equivalent fluid pressure of 35 lbs/ft3 may be used. The active
pressure should be used for walls free to yield at the top at least 0.2 percent of the wall
height. Where the earth slopes upwards at 2:1, an equivalent fluid pressure of 50 lbs/ft3 may
be used. For walls restrained so that such movement is not permitted, an equivalent fluid
pressure of 55 lbs/ft3 should be used, based on at-rest soil conditions with level backfill. The
above pressures assume no hydrostatic pressures. Hydrostatic pressures will increase the
lateral pressures on the wall and we should be contacted for additional recommendations if
applicable. Walls should contain an adequate subdrain to reduce hydrostatic forces. Wall
drain details are given in Figure 4, Wall Drain Details.
7.14 Pavements
Prior to paving the site, the exposed pavement subgrade should be scarified 12 inches,
brought to approximately optimum moisture, and compacted. Aggregate base and the upper
12 inches of subgrade soil should be compacted to at least 95 percent of the maximum dry
density, determined in general accordance with ASTM D1557. Asphalt concrete should be
rolled to at least 95 percent relative compaction based on the Hveem unit weight. Asphalt
concrete should conform to the Standards Specification for Public Works Construction
(SSPWC), Section 203-6. Aggregate base should conform to SSPWC Section 200-2 for
crushed aggregate, crushed miscellaneous, or processed miscellaneous base.
7.14.1 Asphalt Concrete
The parking lots were assumed to have light traffic and passenger car parking, which
would correspond to a Traffic Index (T.I.) of 4.5. R-Value testing was not performed
for this investigation. Prior to paving, R-Value tests should be conducted on the
Geotechnics Incorporated
DAMP-PROOFING OR WATER-
PROOFIN AS REQUIRED ROCK AND FABRIC
•. ALTERNATIVE COIViPAÔED.
BACKFILL
12-INCH -. . . U. MINIMUM
0 .....
MINUS 3/4-INCH CRUSHED ROCK : ENVELOPED IN FILTER FABRIC
•. . .. . . (M1FAFI I40NL, SUPAC 4NP, OR
APPROVED SIMILAR)
..• DAMP-PROOFING OR WATER-' . . PROOFING AS REQUIRED 4-INCH DIAM. PVC
PERFORATED PIPE
GEOCOMPOSITE : 12" PANEL DRAIN
/
lI . COMPACTED.
1 CU. FT PER LINEAL FOOT OF LL
DRAIN MINUS 3/4-INCH CRUSHED
.. . . ALTERNATIVE ROCK ENVELOPED IN . . . FILTER FABRIC. .
4-INCH DIAM. PVC
PERFORATED PIPE
- 'T
NOTES
Perforated pipe should outlet through a solid pipe to a free gravity outfall.
P
e
r
f
o
r
a
t
e
d
p
i
p
e
a
n
d
o
u
t
l
e
t
pipe should have a fall of at least 1%.
As an alternative to the perforated pipe and outlet, weep holes may be inc
l
u
d
e
d
i
n
t
h
e
b
o
t
t
o
m
o
f
t
h
e
wall. Weepholes should be at least 2 inches in diameter, and be spaced n
o
g
r
e
a
t
e
r
t
h
a
n
8
f
e
e
t
.
Filter fabric should consist of Mirafi 140N, Supac 5NP, Amoco 4599, or similar a
p
p
r
o
v
e
d
f
a
b
r
i
c
.
Filter fabric should be overlapped at least 6-inches.
Geocomposite panel drain should consist of Miradrain 6000, J-DRain 400,
S
u
p
a
c
D
S
-
1
5
,
o
r
approved similar product.
5) Drain installation should be observed by the geotechnical consultant pr
i
o
r
t
o
b
a
c
k
f
i
l
l
i
n
g
.
G e o t e c h fl C S WALL DRAIN DETAIL Project No. 0525-001 -00 Incorporated Park Laguna Condominiums
Document No. 9-0484 Architect Judson Pittam
FIGURE 4
ARCHITECT JUDSON PITTAM
PROJECT NO. 0525-001-00 JUNE 7, 1999
DOCUMENT NO. 9-0484
PAGE 18
subgrade materials. An assumed R-Value of 20 was used for design purposes. Base
d
on the assumed T.I. and an R-Value of 20, the pavement section recommended in
accordance with the CALTRANS design method would be 3 inches of asphalt
concrete over 6 inches of aggregate base.
7.14.2 Portland Cement Concrete
Concrete pavement design was conducted in accordance with the simplified design
procedure of the Portland Cement Association. This methodology is based on a 20
year design life. For design, it was assumed that aggregate interlock joints will b
e
used for load transfer across control joints. Furthermore, the portland cemen
t
concrete was assumed to have a minimum 28 day flexural strength of 600 psi. A
"low" subgrade support (corresponding to a modulus of subgrade reaction less th
a
n
120 pci) was assumed for design purposes. Based on these assumptions, w
e
recommend that the pavement section consist of 5 inches ofportland cement concrete
over native subgrade. Crack control joints should be placed on at least 10 foot
centers, each way. Concentrated truck traffic areas, such as trash truck apron, should
be reinforced with at least number 4 bars on 18-inch centers, each way.
8.0 LIMITATIONS OF INVESTIGATION
This investigation was performed using the degree of care and skill ordinarily e
x
e
r
c
i
s
e
d
,
u
n
d
e
r
similar circumstances, by reputable geotechnical consultants practicing in this or simil
a
r
l
o
c
a
l
i
t
i
e
s
.
No other warranty, express or implied, is made as to the conclusions and professional o
p
i
n
i
o
n
s
i
n
-
cluded in this report. The samples taken and used for testing and the observations made ar
e
b
e
l
i
e
v
e
d
representative of the project site; however, soil and geologic conditions can
v
a
r
y
s
i
g
n
i
f
i
c
a
n
t
l
y
between field explorations. As in most projects, conditions revealed by exca
v
a
t
i
o
n
m
a
y
b
e
a
t
variance with preliminary findings. If this occurs, the changed conditions must be
e
v
a
l
u
a
t
e
d
b
y
t
h
e
geotechnical consultant and additional recommendations made, if warranted.
This report is issued with the understanding that it is the responsibility of the ow
n
e
r
,
o
r
o
f
h
i
s
representative, to ensure that the information and recommendations contained her
e
i
n
a
r
e
b
r
o
u
g
h
t
t
o
ceotechnics Incorporated
ARCHITECT JUDSON PITTAIvI PROJECT NO. 0525-001-00 JUNE 7, 1999 DOCUMENT NO. 9-0484
PAGE 19
the attention of the design consultants for the project and incorporated into the plans, and the
necessary steps are taken to see that the contractors carry out such recommendations in the field.
Changes in the condition of a property can occur with the passage of time, whether due to natural
processes or the work of man on this or adjacent properties. In addition, changes in applicable or
appropriate standards of practice may occur from legislation or the broadening of knowledge.
Accordingly, the findings of this report may be invalidated wholly or partially by changes outside
our control. Therefore, this report is subject to review and should not be relied upon after a period
of three years.
GEOTECHNICS INCORPORATED
,__s_ WCJ Sam E. Valdez, PE. 56226 W. Lee Vanderhurst, C.E.G. 1125
Project Engineer Principal
~'thony F. Belfast, P.E. 40333
Principal
Distribution: (4) Addressee
W. LEE \c.
/' VANDERHURST \ I No. 1125
'1 CERTIFIED )
ENGINEERING /
' \ G9 GIST J1
PC
OFESS,o.
No. C566
t'4Qs'
Geotechnics Incorporated
APPENDIX A
REFERENCES
American Society for Testing and Materials (1996). Annual Book of ASTM Standards, Section 4, Construction, Volume 04.08 Soil and Rock (I): D420 - D4914, ASTM, West Conshohocken, PA, 998 pp.
Anderson, J. G. , Rockwell, T. K., Agnew, D. C. (1989). Past and Possible Future Earthquakes of
Significance to the San Diego Region, Earthquake Spectra, Vol. 5, No. 2.
pp 299-335.
Architect Judson Pittam AlA (1999). Site Plan, Park Laguna Condominiums, 1-inch equal 20 feet scale, May 24.
Benton Engineering, Inc. (1991). Final Report on Compacted Filled Ground, Hawthorne
Machinery Company, Carlsbad Facility, 2530 State Street, Carlsbad, California,
July 17.
California Division of Mines and Geology (1975). Recommended Guidelines for D
e
t
e
r
m
i
n
i
n
g
t
h
e
Maximum Credible and the Maximum Probable Earthquakes, California Divisi
o
n
o
f
M
i
n
e
s
and Geology Notes, Number 43.
California Department of Conservation, Division of Mines and Geology (19
9
2
)
.
Fault Rupture Hazard Zones in California, Alquist-Priolo Special Studies Zone Act of 1972: California Division of Mines and Geology, Special Publication 42.
Geotechnics Incorporated (1998). Proposal for Geotechnical Services, Geotechnical Investigation
for Foundation Recommendations, Park Laguna Condominiums, Carlsbad, C
a
l
i
f
o
r
n
i
a
,
Proposal No. 9-092, Document No. 9-0421, dated May 4.
International Conference of Building Officials (1997). Uniform Building Code (w
i
t
h
C
a
l
i
f
o
r
n
i
a
Amendments) Title 24.
Jennings, C. W. (1975). Fault Map of California, California Division of Mines and Geology,
California, Geologic Data Map Series.
Seed, H.B., and Idriss, I.M. (1982). Ground Motions and Soil Liquefaction during Earthquakes:
Berkeley, California, Earthquake Engineering Research Institute, 134p.
Trieman, J. A. (1984). The Rose Canyon Fault Zone --A Review and Analysis,
C
a
l
i
f
o
r
n
i
a
D
i
v
i
s
i
o
n
of Mines and Geology unpublished report, 106 p.
Wesnousky, S. G. (1986). Earthquakes, Quaternary Faults, and Seismic Hazar
d
i
n
C
a
l
i
f
o
r
n
i
a
:
Journal of Geophysical Research, v. 91, no. B 12, p. 12587-12631.
APPENDIX B
SUBSURFACE EXPLORATION
Field exploration consisted of a visual reconnaissance of the site, and t
h
e
d
r
i
l
l
i
n
g
o
f
e
i
g
h
t
e
x
p
l
o
r
a
t
o
r
y
borings with a truck-mounted, hollow stem, continuous flight drill rig o
n
M
a
y
2
0
,
1
9
9
9
.
T
h
e
b
o
r
i
n
g
s
were 8 inches in diameter, and were drilled to a maximum depth of
2
0
f
e
e
t
b
e
l
o
w
c
u
r
r
e
n
t
g
r
a
d
e
.
T
h
e
approximate locations of the borings are shown on the Site Plan,
F
i
g
u
r
e
2
.
L
o
g
s
d
e
s
c
r
i
b
i
n
g
t
h
e
subsurface conditions encountered are presented on the following
F
i
g
u
r
e
s
B
-
i
t
h
r
o
u
g
h
B
-
8
.
Disturbed samples were collected using a Standard Penetration Test (S
P
T
)
s
a
m
p
l
e
r
(
2
-
i
n
c
h
o
u
t
s
i
d
e
diameter). SPT samples were sealed in plastic bags, labeled, and
r
e
t
u
r
n
e
d
t
o
t
h
e
l
a
b
o
r
a
t
o
r
y
f
o
r
testing. Relatively undisturbed samples were collected using a Califor
n
i
a
(
C
A
L
)
s
a
m
p
l
e
r
.
T
h
e
C
A
L
sampler is a ring-lined tube with an inside diameter of 2-3/8 inches an
d
a
n
o
u
t
s
i
d
e
d
i
a
m
e
t
e
r
o
f
3
inches. The ring samples were sealed in plastic bags, placed in a r
i
g
i
d
p
l
a
s
t
i
c
c
o
n
t
a
i
n
e
r
s
,
l
a
b
e
l
e
d
,
and returned to the laboratory for testing. The drive weight for both
S
P
T
a
n
d
t
h
e
r
i
n
g
s
a
m
p
l
e
s
w
a
s
a 140-pound hammer with a free fall of 30 inches. For each sample,
w
e
r
e
c
o
r
d
e
d
t
h
e
n
u
m
b
e
r
o
f
blows needed to drive the sampler 6, 12, and. 18 inches. The number of blows needed to drive the
final 12 inches is shown on the attached logs under "blows per ft.
"
.
U
n
d
i
s
t
u
r
b
e
d
s
a
m
p
l
e
s
w
e
r
e
collected using a 3-inch diameter, 30-inch long, thin walled sample tub
e
(
S
h
e
l
b
y
T
u
b
e
)
.
T
h
e
S
h
e
l
b
y
Tubes (SHE) were sealed with plastic caps and taped. Portions
o
f
t
h
e
S
h
e
l
b
y
T
u
b
e
s
a
m
p
l
e
s
w
e
r
e
extruded for laboratory testing. Bulk samples were also obtaine
d
f
r
o
m
a
u
g
e
r
c
u
t
t
i
n
g
s
a
t
s
e
l
e
c
t
e
d
intervals.
Boring locations were established in the field by pacing and taping and
b
y
e
s
t
i
m
a
t
i
o
n
u
s
i
n
g
t
h
e
p
l
a
n
s
provided. The locations shown should not be considered more accu
r
a
t
e
t
h
a
n
i
s
i
m
p
l
i
e
d
b
y
t
h
e
method of measurement used. The lines designating the interface
b
e
t
w
e
e
n
s
o
i
l
u
n
i
t
s
o
n
t
h
e
b
o
r
i
n
g
logs are determined by interpolation and are therefore approximat
i
o
n
s
.
T
h
e
t
r
a
n
s
i
t
i
o
n
b
e
t
w
e
e
n
t
h
e
materials may be abrupt or gradual. Further, soil conditions at
l
o
c
a
t
i
o
n
s
b
e
t
w
e
e
n
t
h
e
f
i
e
l
d
explorations may be substantially different from those at the specific l
o
c
a
t
i
o
n
s
e
x
p
l
o
r
e
d
.
I
t
s
h
o
u
l
d
be recognized that the passage of time can result in changes in the soi
l
c
o
n
d
i
t
i
o
n
s
r
e
p
o
r
t
e
d
i
n
o
u
r
logs.
Geotechnics Incornorated
I I I I I I I 1) .- _. -•
I I I I I I I I I
-.j cr)
I I I I
DEPTH (FT)m i-
- _______
o
I I
BLOWS PER FT
CL a DRIVE SAMPLE 0 Cr
p
BULK SAMPLE D
DENSITY (PC F) C) __________
_
_
_
_
_
_
_
_
_
_
_
_
___ •
90 MOISTURE (%)
o
•
Q °!CD 10 3W O
-U 0 (C) C U) - 2 . ()) 000
wzz-i -
U) 11 fl) G) ?c0 CD
•
D) )
(n m m m c CD " U)
Q Q) 0 o CD
• CL 0
CD a- -u
III
Ri
0
-
z U)
ED 2 0 CD 0 o (_)
°- • :i
Z
Z
55 C)
2 w 0
o S
-U
0 5 0 - z o
6)
z Cr 3 CD 0
—I m
S
S 0
- 0 0. 0 - (C) CD
'< CD -
<0
- =
O(D
ca
C)
C fl)
CL (1)10 m
W
S Cl)
555S•• - S- S-S
LOG OF EXPLORATION BORING NO. 2
Logged by: CW Date Drilled: 5/20/99 Method of Drilling: 8"-Diameter Hollow Stem Auger Elevation: 41 MSL
LL -j c_s. _j - U.
- LU
co
-
DESCRIPTION LAB TESTS
-J LU 0
0
Old asphalt concrete and gravel.
ELUi Clayey sand to sand (SC-SP), orangish brown, medium, moist, dense. 1
Gravels and cobbles at 1 to 2½ feet.
.3
4
32t
•
.
. Consol. 644 117 11.0 Black stains with hydrocarbon odor.
.7
Debris plastic. 8
10
11
30.
12
13
14
-15
- 16 120 12.3
- 17 -
Refusal at 17 feet.
- - - -
Total depth: 17 feet - 18
No groundwater encountered
No caving - 19
Backfilled: 5/20/99
-20
PROJECT NO. 0525-001-00 GEOTECHNICS INCORPORATED FIGURE B-2
LOG OF EXPLORATION BORING NO. 3
Logged by: CW Date Drilled: 5/20/99 Method of Drilling: 8"-Diameter Hollow Stem Auger Elevation: 42' MSL
-
I.- U. tu j CL
uj
_
-
U.' U.'
DESCRIPTION LAB TESTS a. LU . w 2-' E z - 0 -j CO IQ M M U.'
I Q 1 2 1
Old asphalt concrete and gravel.
TOPSOIL: Sand (SP), brown, medium, moist, loose to medium dense
,
s
o
m
e
asphalt.
- 2
pH Sulfate 14
- Resistivity
BAY POINT FORMATION: Sand (SP), orangish brown, medium, mo
i
s
t
,
d
e
n
s
e
.
Direct Shear 484i: 121 10.7
7
8
.9 Clayey sand (SC), orangish brown, medium to coarse, moist, dense:
10
11 33 i1
12
13
14 ----
-----------------------------
Sand to clayey sand (SP-SC), orangish brown, medium to coarse
,
m
o
i
s
t
,
v
e
r
y
15
dense.
16
52:
Cobbles. 7 - 17
- 18 - - - - -
Total depth: 18 feet 19
Boring hole open for 11/2 hours, water level measured at 17 feet
20 No caving
Backfilled: 5/20/99
PROJECT NO 0525-001-00 GEOTECHNICS INCORPORATED FIGURE B-3
LOG OF EXPLORATION BORING NO.4
Logged by: CW
Date Drilled: 5/20/99 Method of Drilling: 8'-Diameter Hollow Stem Auger
Elevation: 42 MSL
- I- U. Ujj _l _
- -
LU W
DESCRIPTION
LAB TESTS
-J LU 0
CD 0
6" Old asphalt concrete.
1
EJkL Clayey sand (SC) brown to orangish brown fine t
o
m
e
d
i
u
m
m
o
i
s
t
Expansion dense gravels and cobbles
Index
2
74 1i 126 9.4 .4
.5
6
7
3°
8
Dark brown.
10
Gradation
11
36 BAY POINT FORMATION Sand (SF) with silt light to medium orangish
brown, fine, moist, dense, friable.
12
13
--
Sand (SF), light gray to orangish gray, coarse, moist, very d
e
n
s
e
,
s
o
m
e
15
cobbles.
16
5 .I;
17
Total depth: 17 feet is
No groundwater encountered
No caving 19
Backfilled: 5/20/99
20
PROJECT NO. 0525-001-00 GEOTECHNICS INCORPORATED
FIGURE B-4
rE ; C7:3 CT ET CT TT) CTJ TT)
DEPTH (FT) ________________
_
_
_
_
_
_
_
_
_
________ _______________
_
_
_
_
_
_
_
_
_
BLOWS PER FT
CL CL 2 DRIVE SAMPLE o
1 -
BULK SAMPLE 0
DENSITY (PCF) co
oLrl
Ln MOISTURE (¼) (11
b
r
o
a 0 -u - 0
CI)3 0
(1,
0 -.
6)
CD
0
fl m 0 0. — (D m 0 —' o
.' a. >< —I Ln 0' 0 -u m
— C) (,
0 I
. 77 Cl)0 m en
CD z 0 —
C) a. — (I)
0 CL I -uzr - Z 1) —, — 0 0
-,
0 z
(0 - CD
-.
-
Z o — 3
2. G) 2.' . U,
- z 3 0 - a., CD (I) :
sm C m — CD
0
1- ..C.pI -n
w
(ow
C
—
m
IT!
cn
— I 1 I I I I I - - - -. - -
I I r
- - -
I I I I I I I I I I (C) C)) -) C)) (I) w() DEPTH (FT) o
—
BLOWS PER FT C)
O.. _________________________________________ i I 1 _______
DRIVE SAMPLE Cr o ____________________
_
_
_
_
_
_
_
_
_
— BULK SAMPLE D
DENSITY(PCF) co
MOISTURE (%) co
Q 9r
-0 g D 0
3 0 WZZ fl)OO9 ( (b
a-2 — 0 3 m 0 6) 5 m m 5CCD 0 a-
0 m 0)
C.) mo
a- o
5 . 5 -u m
— - '. I (1) CD j' j- 0 z a. Cl) I a-
- m ' 13 Z
3 -
0 P a- o - a- C)
C 0) CD 5 -
0 - a-
- .
-' z 2:
CL CD 0 C-) 0) 3 z r-..
- 2. 0 0 -u
(a 3 CD - Z Li w =r C a- S 3 a. CD —I
- m o
. -
H.
cyl I- L C)
W C
cn co m m
Cfl
Cl)
- -. - -. - - -
to 03 -'J 0) DEPTI-J(FT) o
to
L.
BLOWS PER FT CO C)
-
CL a DRIVE SAMPLE
- BULK SAMPLE cj
DENSITY (PCF)
Ln
MOISTURE (%) a
(D
fD
E
in r7 0
0 O(O LI) -
CD - m
-, a)
m
o
LI) 0 01 7-4 :E
(
En
0 lu
m
CD U CD z
. OL O) Cl) 3 - ç) 8 0 cr 0 1
01
CD
)_2.
CD
0
3 CD 2-. <0 C
3
116 cn G)
W cog r
m
Cl)
-u 0 CD 0) J - 0) 0) 0 w I -' U t, 1.J DEPTH (FT) ' '
BLOWS PER FT
- Ii ______________________
_
_
_
_
_________________________
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
_
DRIVE SAMPLE oCr
p
BULK SAMPLE
M.
o I
DENSITY (PCF)
CA
6 CD
MOISTURE ill<
_____________________
_______ CL 9
0
ct -.'
-
-- 0
IWZG - > 2 - -<
o a)
Dl 0OW
CDO
-Zn 0 tl.. M 0 a) = < CD
Ti
0 -. 0
(fl < 0
E 1 fl
UI I
0 2r
Cl) 5 PL a)g
-
I cr in ET 0 ><
0
o a) '< CD —
-,
-
cn
CD Q
—J
0 z
Zcr
o. to
2 W
0 -o
CD
=
—
U
z
Q CD 0
CD —48 m3
-
3
- O f CD CD
CL a)
3
3 CD - U 2.
(I)
CD -
CDi
(Cl
tn
1
C
m
m
APPENDIX C
LABORATORY TESTING
Selected samples of soils encountered during the investigation were tested usi
n
g
g
e
n
e
r
a
l
l
y
a
c
c
e
p
t
e
d
testing standards. The soils selected for testing are believed to be generally
r
e
p
r
e
s
e
n
t
a
t
i
v
e
o
f
t
h
e
materials encountered during the investigation at the site; however variati
o
n
s
m
a
y
o
c
c
u
r
i
n
t
h
e
s
o
i
l
s
at the site, and the materials tested may not be representative of the materi
a
l
s
e
n
c
o
u
n
t
e
r
e
d
d
u
r
i
n
g
construction.
Laboratory testing was conducted in a manner consistent with that level of
c
a
r
e
a
n
d
s
k
i
l
l
o
r
d
i
n
a
r
i
l
y
exercised by members of the profession currently practicing under similar cond
i
t
i
o
n
s
a
n
d
i
n
t
h
e
s
a
m
e
locality. No other warranty, expressed or implied, is made as to the correctnes
s
o
r
s
e
r
v
i
c
e
a
b
i
l
i
t
y
o
f
the test results or the conclusions derived from these tests. Where a spec
i
f
i
c
l
a
b
o
r
a
t
o
r
y
t
e
s
t
m
e
t
h
o
d
has been referenced, such as ASTM, Caltrans, or AASHTO, the refere
n
c
e
a
p
p
l
i
e
s
o
n
l
y
t
o
t
h
e
specified laboratory test method and not to associated referenced test method(
s
)
o
r
p
r
a
c
t
i
c
e
s
,
a
n
d
t
h
e
test method referenced has been used only as a guidance document for the
g
e
n
e
r
a
l
p
e
r
f
o
r
m
a
n
c
e
o
f
the test and not as a "Test Standard." A brief description of the tests perfor
m
e
d
f
o
l
l
o
w
s
:
Classification: Soils were classified visually according to the Unified Soil Classification
S
y
s
t
e
m
as established by the American Society of Civil Engineers. The resultant soil
c
l
a
s
s
i
f
i
c
a
t
i
o
n
s
a
r
e
shown on the Boring Logs in Appendix B.
In-Situ Moisture/Density: The in-place moisture content and dry unit weight of selected soil
samples were determined using relatively undisturbed samples from th
e
l
i
n
e
r
r
i
n
g
s
o
f
a
C
A
L
sampler. The dry unit weight and moisture content are shown on the boring l
o
g
s
i
n
A
p
p
e
n
d
i
x
B
.
Particle Size Analysis: Particle size analyses were performed in general accordance with the
laboratory procedures outlined in ASTM test method D 422. The grain si
z
e
d
i
s
t
r
i
b
u
t
i
o
n
w
a
s
u
s
e
d
to estimate presumptive soil strength parameters and foundation design criter
i
a
.
T
h
e
r
e
s
u
l
t
s
a
r
e
given in Figures C-i and C-2.
Expansion Index: The expansion potential of a selected soil was estimated in general accordance
with the laboratory procedures outlined in ASTM test method D 4829. Fig
u
r
e
C
-
3
p
r
o
v
i
d
e
s
t
h
e
results of the test.
Sulfate Content: To assess the potential for reactivity with below grade concrete, a selected
s
o
i
l
sample was tested for water-soluble sulfate content in general accordance with
t
h
e
S
t
a
n
d
a
r
d
M
e
t
h
o
d
for Evaluation of Waste Water Test S MEWW45 00 S 04E. which is conducted in general conformance with EPA Test Method 375.4. The results are presented on Figure C-3.
Geotechnics Incornorated
I
APPENDIX C
LABORATORY TESTING (continued)
pH and Resistivity: To assess the potential for reactivity with buried metal pipe and below grade
ferrous materials, selected soil samples were tested for pH and resistivity in gene
r
a
l
a
c
c
o
r
d
a
n
c
e
w
i
t
h
the laboratory procedures outlined in Caltrans test method 643. The results are show
n
o
n
F
i
g
u
r
e
C
-
3
.
Direct Shear: The shear strength of selected soil samples was assessed through direct shear test
i
n
g
performed in general accordance with the laboratory procedures outlined in AST
M
t
e
s
t
m
e
t
h
o
d
D 3080. The results are summarized in Figure C-4.
Consolidation Test: In order to evaluate the compressibility of the soils at the site, one-dimensional
consolidation properties of a selected soil sample was evaluated in general accord
a
n
c
e
w
i
t
h
t
h
e
laboratory procedures outlined in ASTM test method D 2435. The soil sample was saturated at
approximately the overburden stress and then subjected to incrementally applied c
o
n
t
r
o
l
l
e
d
s
t
r
e
s
s
loading. The soil samples were restrained laterally and drained axially, while loa
d
e
d
.
T
h
e
t
e
s
t
results are summarized on Figure C-5.
L
U.S. Standard Sieve
3' 1-1/2" 3/4" 3/8" #4 #8 #16 #30 #50 #100 #200
Hydrometer IUU
80
60
>
.0
CD
30
.
90
::ji
iIiiI 5 IT
----.
5O ------------.-.---
---.- --------------
10-
IIITTL J] ___ IIEEEUJ I I 100 10 1 0.1 0.01 0.001 Grain Size in Millimeters
COARSE FINE COARSE MEDIUM FINE
SILT AND CLAY GRAVEL SAND
SAMPLE UNIFIED SOIL CLASSIFICATION:
ATTERBERG LIMITS EXPLORATION NUMBER: B-i
LIQUID LIMIT: SAMPLE DEPTH: 10' DESCRIPTION: BAY POINT FORMATION: Sand (SP) with silt PLASTIC LIMIT.-
PLASTICITY INDEX:
Geo technics Project No. 0525-001-00 I n c o r p o r a t e d SOIL CLASSIFICATION Document No. 9-0484
FIGURE C-I
rev. 3-98
U.S. Standard Sieve
3" 1-1/2" 3/4 3/8 #4 #8 #16 #30 #50 #10
0
#
2
0
0
Hydrometer
10 1 0.1 0.01 0.001 Grain Size in Millimeters
COARSE FINE COARSE MEDIUM FINE
SILT AND CLAY GRAVEL SAND
SAMPLE UNIFIED SOIL CLASSIFICATION:
ATTERBERG LIMITS
EXPLORATION NUMBER: B-4
LIQUID LIMIT: SAMPLE DEPTH: 10' DESCRIPTION: BAY POINT FORMATION: Sand (SP) with silt
PLASTIC LIMIT.-
PLASTICITY INDEX:
Geotechnics
Project No. 0525-001-00 1 n c o r p o r a t e d SOIL CLASSIFICATION Document No. 9-0484
FIGURE C-2
rev. 3-98
EXPANSION INDEX TESTS
(ASTM D4829)
SAMPLE I SAMPLE DESCRIPTION EXPANSION EXPANSION NUMBER INDEX POTENTIAL
B4 at 1' to 3' [_Brown to orangish brown Clayey sand (SC) ] 17 1 VeryLow
UBC TABLE NO. 29-C, CLASSIFICATION OF EXPANSIVE SOIL
EXPANSIONINDEX POTENTIALEXPANSION
0-20 Very Low
21-50 Low
51-90 Medium
91-130 High
Above130 VeryHigh
SULFATE CONTENT TEST RESULTS
(SMEWW450OSO4E)
SAMPLE I SULFATE[%]
83at2' I .0086
CORROSIVITY TEST RESULTS
(Caltrans Test Method 643)
SAMPLE pH RESISTIVITY
B3 at 2' to 3' 8.39 1256
Ge o t e c h n i c s Laboratory Test Results Project No. 0525-001-00 Incorporated Park Laguna Condominiums Document No. 9-0484 Architect Judson Pittam FIGURE C-3
rann
SAMPLE: B3@5 PEAK ULTIMATE
BAY POINT FORMAITON: Sand (SP) 47 ° 40 0
OPSF OPSF
___ IN-SITU AS-TESTED STRAIN RATE: 0.0100 IN/MIN 1 Yd 120.5 PCF 120.5 PCF (Sample was consolidated and drained) w 10.7 % 16.8 %
G e o t c h n i c s DIRECT SHEAR TEST RESULTS Project No. 525-001-00
Incorporated Park Laguna Condominiums Document No. 9-0484
Architect Judson Pittam FIGURE C-4
0.00%
1.00%
2.00%
U)
4-
U
3.00%
4.00%
500%
10.0 100.0 1000.0 10000.0 Stress [psf]
B2 @ 5' Water added to sample after consolidation under a load of 1,97
3
p
s
f
.
INITIAL FINAL
SAMPLE HEIGHT [IN]
I DRY DENSITY [PCF] I SPECIFIC GRAVITY
. I VOID RATIO I WATER CONTENT [%]
DEGREE OF SATURATION [%]
I
,g=6,.Geotechnics I Consolidation Test Results Project No. 0525-001 -00 1 Park Laguna Condominiums Document No. 9-0484 I Incorporated
I Architect Judson Pittam FIGURE C-5
1.0000 0.9757
116.6 119.5
2.70 2.70
0.45 0.41
11.0 13.9
66.7 91.6