HomeMy WebLinkAbout20210922124223465.pdf.pdfY1 rq GA @343 bra P&4s f. _s ra','
a,
M,uA01.1
Environmental
La6oratory
August 30, 1999
S & W Development
20547 Walnut Drive
Suite D
Walnut, California 91789
Attention: Mr. Simon Shum
Subject: Report of Geotechnical and Geological Investigation
Proposed Residential Development
2501 Crowfoot Lane
Diamond Bar, California
EGL Project No.: 99-181-006EG
Gentlemen:
In accordance with your request, Environmental Geotechnology Laboratory, Inc. (EGL) is
pleased to submit this Geotechnical Engineering and Geological Report for the subject site. The
purpose of this report was to evaluate the subsurface conditions and provide recommendations
for foundation designs and other relevant parameters of the proposed construction.
Based on the findings and observations during our investigation, it is concluded that the
proposed construction of the subject site for the intended use_ is feasible from the geotechnical
engineering and geological viewpoints, provided that specific recommendations set forth herein
are followed.
This opportunity to be of service is sincerely appreciated. if you have any questions pertaining
to this report, please call the undersigned.
Respectfully submitted,
Environmental Geotechnology Laboratory, Inc.
5k C. Lee, GE 2153
Principal
Dist: (4) Addressee
NO,2153 r,
0IC`''
CAO
Hank H. ,Jong, Ph.D,
Principal
164E
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670 d Tel: (562) 945-0689, Fax: (562) 945-0364
E-MAIL: EGL88@AOL.COM
REPORT OF GEOTECHNICAL ENGINEERING
AND ENGINEERING GEOLOGICAL
INVESTIGATION
Proposed Residential Development
At
2501 Crowfoot Lane
Diamond Bar, California
Prepared by
ENVIRONMENTAL GEOTECHNOLOGY LABORATORY, INC.
Project No.: 99-181-006EG
August 30, 1999
S & W Development EGL Project No.: 99-181-006EG
TABLE OF CONTENTS
1.0 INTRODUCTION.......................................................................................................I........................... 1
i
1
1.1 PURPOSE..................................................................................................
1.2 SCOPE OF SERVICES
1.3 PROPOSED CONSTRUCTION...................... ...............................................
1.4 SITE CONDITIONS
1
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING 2
2.1 SUBSURFACE EXPLORATION.................................................................................................................. 2
r.
2.2 LABORATORY TESTING..........................................................................................................................
2
3.0 GEOLOGIC SETTING........................................................................................................................... 2
3.1 REGIONAL GEOLOGY......................................................................................... 2
f
3.2 SITE GEOLOGY... ............. ............................. ........ ...............................................................
2
3.3 GEOLOGICAL STRUCTURES............................................................................................. 3
j3.4 GROUNDWATER............................................................................................................
3
4.0 SEISMICITY...........................................................................................................................................3.
4.1 FAULTING.............................................................................................................................
3
4.2 SEISMICITY........................................................................................................................................... 3
4.3 ESTIMATED EARTHQUAKE GROUND MOTIONS........................................................................................ 4
5.0 SLOPE STABILITY................................................................................................................................ 4
5.1 EXISTING SLOPES.................................................................................................................................
4
t
5.2 CUT SLOPE........................... .................................. .........................................................
5.3 SLOPE STABILITY AND LANDSCAPING..................................................................................................... 5
I6.0 CONCLUSIONS.................................................................................................................................... 5
6.1 SEISMICITY...............................................................,............................................................. 5
6.2 EXCAVATABILITY...................................................................................................................................
5
6.3 SURFICIAL SOIL REMOVAL AND RECOMPACTION..................................................................................... 6
6.4 GROUNDWATER......................................................................................................................I............. 6
7.0 RECOMMENDATIONS......................................................................................................................... 6
7.1 GRADING.............................................................................................................................................. 6
7.1.1 Site Preparation...........................................................................................................................
7.1,2 Surficial Soil Removals..................................................................................................I............. 6
7.1.3 Treatment of Removal Bottoms................................................................................................... 6
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: (562) 945-0689; Fax: (562) 945-0364
EGL Project No.: 99-181-006EG
S & W Development
7.1.4 Structural Backfill............................................ ................................
I ....... 1 6
7.1.5 Stabilization Fill .................................. .............................................
7
7
7.1.6 Benching
7.1.7 Fill Slopes ................................. ..............................................................
7
7.1.8 Cut Slopes ................................ ...........................................................
7
7.2 FOUNDATION DESIGN..........................................................................
7
7.2.1 Bearing Value ........ ....... ... .........................................................................
7
T2.2 Settlement ....................................... ..............................................
7
7.2.3 Foundation Setback .......................................... ..................
8
T2.4 Lateral Pressures— .......................... ...................... ..............................
8
7.3 FOUNDATION CONSTRUCTION .....................
I......... 8
7A CONCRETE SLABS.........................................................................
8
9
7.6 WALL BACKFILL.............................................................
7.7 TEMPORARY TRENCH EXCAVATION AND BACKFILL..................................................................................
9
8.0 CORROSION POTENTIAL...................................................................................................................
9
9.0 SEISMIC DESIGN...............................................................................................................................
10
10.0 111 STATEMENT..............................................................................................................................
10
11.0 INSPECTION............................................................. I.......................................................................
10
12.0 INVESTIGATION LIMITATIONS....................................................................................................
11
a
APPENDIX A FIELD INVESTIGATION
APPENDIX B LABORATORY TESTING
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: (562) 946-0689; Fax: (562) 945-0364
S & W Development
Page 1 of
EGL Project No.: 99-181-006EG August 30, 1999
1.0 INTRODUCTION
1.1 Purpose
This report presents a summary of our preliminary geotechnical engineering and engineering
geological investigation for the proposed construction at the subject site. The purposes of this
investigation were to evaluate the subsurface conditions at the area of proposed construction and
to provide recommendations pertinent to grading, foundation design and other relevant
parameters of the proposed development.
1.2 Scope of Services
Our scope of services included:
Review of available soil and geologic data of the area.
Subsurface exploration consisting of logging and sampling of three test pits. The test pits
were extended to a maximum depth of 4 feet below the existing ground surface. Test pit logs
are presented in Appendix A.
i • Laboratory testing of representative samples to establish engineering characteristics of the
l on -site soil. The laboratory test results are presented in Appendices A and B.
i • Engineering analyses of the geotechnical data obtained from our background studies, field
investigation, and laboratory testing.
Preparation of this report presenting our findings, conclusions, and recommendations for the
proposed construction.
1.3 Proposed Construction
It is understood that the proposed construction consists of cut and fill grading operation to create
a building site for the planned residential building and associated structures. Column loads are
unknown to us at this time, but are expected to be light to medium.
1.4 Site Conditions
The subject site is located at 2501 Crowfoot Lane in the City Diamond Bar, California. The
approximate regional location is shown on the attached Site Location Map (Figure 1). A westerly
descending slope occupies the property. The average slope ratio is approximately 2.5 to 1
horizontal to vertical). The slope area is generally covered with low grasses and weeds. No
major erosions were observed during our field investigation. Detailed configuration of the site and
existing topography are presented in the attached plan (Figure 2).
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
r.
Fibmr—
ENVIRONMENTAL Project Address:
GEOTECHNOLOGY
LABORATORY 1 2501 Crowfoot LaneIIiIIAVM
SITE LOCATION MAP
8/99. FIGURE 1
S & W Development Page 2 of 11
EGL Project No.: 99-181-006EG August 30, 1999
2.0 SUBSURFACE EXPLORATION AND LABORATORY TESTING
2.1 Subsurface Exploration
Three test pits were excavated to a maximum depth of 4 feet at the locations shown on the
attached Site Plan, Figure 2. The test pits were supervised and logged by an EGL's geotechnical
engineer and an engineering geologist. Relatively undisturbed and bulk samples were collected
for laboratory testing. Logs of test pit are presented in Appendix A.
2.2 Laboratory Testing
Representative samples were tested for the following parameters: in -situ moisture content and
density, consolidation, direct shear strength, and corrosion. Results of our laboratory testing
along with a summary of the testing procedures are presented in Appendix B. In -situ moisture
and density test results are presented on the boring logs in Appendix A.
3.0 GEOLOGIC SETTING
3.1 Regional Geology
The project site is located on the northeastern frank of the Puente Hills. The Puente Hills are
roughly bounded on the northwest by the Chino Fault zone and on the southwest by the Whittier
N. Elsinore Fault zone. The Chino Fault zone terminates at its north end into the Raymond/Sierra
Madre/Cucamonga Fault complex. This termination occurs several miles north of the site.
The Puente Hills are primarily underlying by Miocene and Pliocene sedimentary rock. These rock
have been folded and faulted as part of a compressional block between the above mentioned two
fault zones.
3.2 Site Geology
The project site is underlain by Puente Formation bedrock. This bedrock typically consists of
siltstone and lenses of sandstone. The bedrock is overlain by artificial fill and slopewash.
Description of the subsurface materials from top down is provided as follows:
Artificial Fill (Af) — The relatively level pad area on the property are blanketed with a mantle of
artificial fill that consists of medium to dark brown, silty to clayey fine-grained
sand that is typically dry to damp and loose. Where observed in our exploratory
excavations, this material reached a maximum thickness of about 0.5 feet. Fill
has not been delineated on the attached geologic map (Figure 2)..
11823 Slauson Avenue, Unit 18. Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
n sw'2z'ne'E
ZM2.79' 519R2'06•E 200
1
vD_—_—_--_----'
a _
2
VF
Shako rAIF
Approximate Location ; y
of Recommended Key f5'
tg
ors FL'
X3' a
3 NH
z
I
7W UU3LZ"=Z rYWcrnzG a
W as ZZz y 00 DU=x YV
Q z'
r
W
0 - :
2 it W
j ?- 6 6z vi_i'S Ci 3 . y JLEGEND:
existing
contour new
contour 25
strike and dip of bedding approximate
location of
test pits T-
1 Scale
1 ":40' i
li
Address: Environmental
2601 crowfoot Lane 1 : .. .
Geoteahnology Diamond gar, California 0• -"""
Laboratory SITE (
Geology) PLAN 8/
99 i
FIGURE
2
S & W Development Page 3 of 11
EGL Project No.: 99-181-006EG August 30, 1999
Slopewash - Silty clay, gray to dark brown in color, soft to firm and slightly moist. Some
hairline roots were also observed within these soils. These deposits are typically
less than one feet thick, porous.
Siltstone — The subject site is underlain by the bedrock of Puente Formation. The test pits
encountered medium to yellowish brown siltstone with thin layer of silty
sandstone. The bedrock materials are generally medium hard and moist.
3.3 Geological Structures
Bedding orientation varies locally, but generally strikes northeast dipping to the east. The angles
of dip measured in our test pit. is approximate 5 to 14 degrees. No faulting was observed in the
test pits as well as in our surface mapping.
3.4 Groundwater
No ground water was encountered during our field investigation to a maximum depth of
approximately 4 feet. Groundwater is not expected to be a significant constraint during future
construction.
4.0 SEISMICITY
4.1 Faulting
By definition of the California Mining and Geology Board, an active fault is a fault that has had
surface displacement within Holocene time (about the last 11,000 years). A potentially active
fault is defined by the State Geologist as any fault that has been active during Quaternary time
the last 1,600,000 years). Based on our study, there are no known active faults crossing the
property. The known active regional fault is the Whittier -North Elsinore Fault zone located about
4 miles from the site.
4.2 Seismicity
The subject site is located in southern California, which is a tectonically active area. The type and
magnitude of seismic hazards affecting the site depend on the distance to causative faults, the
intensity, and the magnitude of the seismic event. Table 1 indicates the distance of the fault zones
and the associated maximum credible earthquake that can be produced by nearby seismic events.
11823 Slauson Avenue, unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
v
fI
f
cr7
Z
o O
J F-
L)
o
04
0
U
2ioo U
Z URN O
UM 0
LU
C7
Oi
aaf uvi ta Ia
S & W Development Page 4 of 11
EGL Project No.: 99-181-006EG August 30, 1999
TABLE 1
Characteristics and Estimated Earthquakes for Regional Faults
Fault Name Approximate Distance to
Site(mile)
Maximum Credible Earthquake
MCE)
Whittier-N. Elsinore 4 7.1
Chino 5 6.7
San Jose 6 6.5
Sierra Madre -San Fernando 10 6.7
Cucamonga 15 7.0
Raymond 17 6.5
Clamshell-Sawpit 17 6.5
San Gabriel 22 7.0
Verdugo 22 6.7
Newport -Inglewood 24 6.9
Newport -Inglewood (Offshore) 24 6.9
San Andreas (Mojave) 28 7.1
3
4.3 Estimated Earthquake Ground Motions
In order to estimate the seismic ground motions at the subject site, EGL has utilized the seismic
hazard map published by California Divisions of Mines and Geology (CDMG Open File Report
96-08) 1 U.S. Geological Survey (USGS Open File Report 97-706). According to this report, the
peak ground acceleration for at the subject site for a 10% probability of exceedance in 50 years is
at least 0.50-0.60g. This report also indicates that the subject site is location within a zone where
the magnitude range is 6.5-7.0.
5.0 SLOPE STABILITY
5.1 Existing Slopes
Existing slopes are at an average slope ratio of 2:1 or flatter. Existing slopes within the subject
site were observed and probed during our field investigation and are considered satisfactory and
should possess adequate factors of safety against instabilities provided they are properly
maintained.
Based on the relatively stable condition of the existing natural slopes, we recommend that the
existing slopes outside the proposed construction areas be left in their natural conditions (with a
moderate growth of vegetation). Should additional planting be desired, only moderate irrigation
should be applied.
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
S & W Development
EGL Project No.: 99-181-006EG
Page 5of11
August 30, 1999
5.2 Cut Slope
Cut slopes are currently planned at a ratio of flatter than 2.1 up to height of less than 10± feet.
Cut slopes should possess adequate factors of safety against deep seated failure providing
jointing, bedding, or other planar structure is favorably oriented.
The cut slope below the proposed building pad is generally composed of siltstone of Puente
Formation and oriented in the same direction as the low -angle bedding inclination. A stabilization
fill is recommended for this cut slope.
5.3 Slope Stability and Landscaping
All slopes will be subject to surficial erosion. Therefore, slopes should be protected from surface
runoff by means of top -of -slope compacted earth berms or concrete interceptor drains. All slopes
should be landscaped with a suitable plant material requiring minimal cultivation and irrigation
water in order to thrive. An irrigation system should be installed, Overwatering and subsequent
saturation of slope surfaces should be avoided.
6.0 CONCLUSIONS
Based on the results of our subsurface investigation and engineering analyses, it is our opinion
i
E
that the proposed construction is feasible from a geotechnical standpoint, provided the
recommendations contained herein are incorporated in the design and construction. The
following is a summary of the geotechnical design and construction factors that may affect the
I
development of the site:
6.1 Seismicity
Based on our studies on seismicity, there are no known active faults crossing the property.
However, the site is located in a seismically active region and is subject to seismically induced
ground shaking from nearby and distant faults, which is characteristics of all Southern California.
6.2 Excavatability
Based on our subsurface investigation, excavation of the subsurface materials should be able to
be accomplished with conventional earthwork equipment.
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
S & W Development
EGL Project No.: 99-181-OO6EG
6.3 Surficiial Soil Removal and Recompaction
Page 6 of 11
August 30, 1999
Based on our field investigation and laboratory testing results, the site is underlain by a layer of
slopewash and artificial fill which are relatively soft and dry. These soils should be removed to
expose competent bedrock.
6.4 Groundwater
Groundwater was not encountered during our field exploration. In our opinion, groundwater will
not be a problem during construction.
7.0 RECOMMENDATIONS
Based on the subsurface conditions exposed during field investigation and laboratory testing
program, it is recommended that the following recommendations be incorporated in the design
and construction phases of the project.
7.1 Grading
7.1.1 Site Preparation
Prior to initiating grading operations, any existing vegetation, debris, over -sized materials (greater
than 6 inches), and other deleterious materials within fill areas should be removed from the site.
7.1.2 Surficial Soil Removals
In order to provide a uniform support for the concrete slab, unsuitable surfacial materials,
including existing slopewash and fill should be removed to expose competent bedrock or to a
minimum depth of 18 inches below the final pad grade, whichever is deeper. The depth of
removals may vary with locations. The actual removal depths should be determined in the field as
conditions are exposed. Visual inspection and/or testing may be used to define removal
requirements.
7.1.3 Treatment of Removal Bottoms
Soils exposed within areas approved for fill placement should be scarified to a depth of 6 inches,
conditioned to near optimum moisture content, then compacted in -place to project standards.
7.1.4 Structural Backfill
The onsite soils may be used as compacted fill, provided they are free of organic materials and
debris. Fills should be placed in relatively thin lifts, brought to near optimum moisture content,
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
S & W Development
EGL Project No.: 99-181-006EG
Page 7of11
August 30, 1999
then compacted to. obtain at least 90 percent relative compaction based on laboratory standard
ASTM D-1557-91.
7.1.5 Stabilization Fill
Stabilization fills should be constructed at the location below the proposed building pad. Fill key
should be a minimum of 12 feet wide and extend a minimum of 3 feet into the competent bedrock.
The recommended location of the key is presented in the attached site plan (Figure 2). All keys
should be inspected and approved by the project geotechnical consultant.
7.1.6 Benching
Fills placed on slopes steeper than 5:1 should be keyed and benched into competent materials as
the fill is placed. Keys and benches should be observed by the project geotechnical consultant.
7.1.7 Fill Slopes
Permanent fill slopes should be constructed no steeper than 2.1 (horizontal to vertical) and keyed
and benches into approved soil/bedrock materials. Fill materials should be placed and
compacted in accordance with the text of this report.
7.1.8 Cut Slopes
Cut slopes should be inspected by the project geotechnical consultant. Unanticipated conditions
could require corrective grading of cut slopes. Final determination of the need, location and extent
of any required stabilization should be determined based on conditions exposed during grading.
j 7.2 Foundation Design
7.2.1 Bearing Value
An allowable bearing value of 2000 pounds per square foot may be used for design of wall
footings 12 inches wide and 18 inches deep. This bearing value may be increased by 200 psf for
each additional foot of depth or width to a maximum value of 3000 psf. This value may be
increased by one-third when considering short duration seismic or wind loads.
7.2.2 Settlement
Settlement of the footings placed as recommended and subject to no more than allowable loads
is not expected to exceed 112 inch. Differential settlement between adjacent columns is not
anticipated to exceed 114 inch.
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
S & W Development Page 8 of 11
EGL Project No.: 99-181-006EG August 30, 1999
7.2.3 Foundation Setback
It is recommended that all settiement-sensitive foundations be located a minimum of 15 horizontal
feet from the descending slope face and setback per County's building code requirements.
7.2.4 Lateral Pressures
The active earth pressure to be utilized for cantilever retaining wall design may be computed as
an equivalent fluid pressure of 35 pounds per cubic foot (pcf) when the slope of the backfill
behind the wall is level. When the slope of the backfill is 2:1, an equivalent fluid pressure of 50 pcf
may be used.
Passive earth pressure may be computed as an equivalent fluid pressure of 250 pounds per
cubic foot, with a maximum earth pressure of 3,000 pounds per square foot. An allowable
coefficient of friction between soil and concrete of 0.35 may be used with the dead load forces.
When combining passive pressure and frictional resistance, the passive pressure component
should be reduced by one-third.
No passive pressure is allowed for the portion of the footings which maintain less than 5
horizontal feet between the face of the slopes and the edge of the footings.
7.3 Foundation Construction
All footings for structures and walls should be founded in competent bedrock materials and
should be founded at least 24 inches below the lowest adjacent ground surface. All continuous
Tootings should have a minimum of two No. 4 reinforcing bars placed at the top and bottom of the
footing. A grade beam reinforced as recommended above for footings and at least 12 inches
square should be utilized across the garage entrance. The base of the reinforced beam should
be at the same elevation as the bottom of the adjoining footings.
7.4 Concrete Slabs
All concrete slabs should be at least four inches in thickness. Concrete slabs in moisture sensitive
areas should be underlain with four inches of washed sand or crushed rock. In addition, a vapor
barrier consists of a minimum of six mil polyvinyl chloride membrane with all laps sealed should
i also be provided. A minimum of one inch of sand should be placed over the membrane to aid in
uniform curing of concrete.
11823 Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
Page 9 of 11
S & W Development August 30, 1999
EGL Project No.: 99-181-006EG
Concrete slabs should be reinforced with a minimum 6x6-616 welded wire mesh or its equivalent.
All slab reinforcement should be supported to ensure proper positioning during placement of
concrete. Garage slab should be pours separately from the residence footings. A positive
separation should be maintained with expansion joint materials to permit relative movement.
7.6 Wall Backfill
The wall backfill and any other structures should be compacted. All soil backfill should be
compacted to obtain a minimum relative compaction of 90 percent of the ASTM D-1557-91. No
flooding and/or jetting is allowed for the onsite soils. Adequate drainage system should be
provided behind the walls to prevent the build-up of any hydrostatic pressure. Observation and
l testing of all compaction should be performed under the direction of the project geotechnical
engineer.
l 7.7 Temporary Trench Excavation and Backfill
OSHA and local safety codes.. All utilities trenchAlltrenchexcavationsshouldconformtoCAL
backfill should be brought to near optimum moisture content and then compacted to obtain a
n minimum relative compaction of 90 percent of ASTM D-1557-91.
8.0 CORROSION POTENTIAL
Chemical laboratory tests were conducted on the existing onsite near surface materials sampled
during EGL's field investigation to aid in evaluation of soil corrosion potential and the attack on
l R concrete by sulfate soils. The testing results are presented below:
Chloride Sulfate iviin. Kesssuvity
Sample Location PH (ppm) (% by weight) (ohm/cm)
T-2 @ 0-3' 7.87 130 0.004 1010
According to UBC Table 19-A-3, a "negligible" exposure to sulfate can be expected for concrete
placed in contact with the onsite soils. Therefore, Type II cement or its equivalent may be used
for this project.
l Based on the resistivity test results, it is estimated that the subsurface soils are corrosive to
buried metal pipe. It is recommended that any underground steel utilities be blasted and given
high quality protective coating. Should additional protective measures be warranted, a corrosion
specialist should be consulted.
11823 siauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
Page 10 of 11
S & W Development August 30, 1999
EGL Project No.: 99-181-006EG
9.0 SEISMIC DESIGN
The following 1997 Uniform Building Code (UBC) geotechnical related values may be used for
the subject structural design:
Seismic Zone 4
Seismic Zone Factor (Z) 0.4
Soil Profile Type — Table 16-J Sc
Seismic Coefficient Ca (16-Q) 0.40Na
Cv (16-R) 0.56Nv
Near Source Factor Na (16-S) 1.0
Nv (16-T) 1.2
Seismic Source Type (16-U) B
Uniform Building Code designs is intended to accommodate horizontal accelera ommod to
up to 0this
for Seismic Zone 4. The proposed structures should be designedsgdto should
be aware of the acceleration,
at a minimum. However, the Project Structural information
provided above to determine if any additional structural strengthening is warranted. 10.
0 111 STATEMENT it
is our opinion that the grading Based
on our field investigation and the laboratory testing results, a
settlement, or slippage and andproposedstructureswillbesafeagainsthazardfromlandslid , rseaffectonthegeologicstability of the adjacent theproposedconstructionwillhavenoadveproperties
provided our recommendations are followed. 11.
0 INSPECTION As
a necessary requisite to the use of this report, the following inspection is recommended: Temporary
excavations. Removal
of surficial and unsuitable soils. Backfill
placement and compaction. Utility
trench backfili. The
geotech nical engineer should be notified at least 2 day in advance of the start of construction. A joint meeting between the client, the contractor, and the geotechnical engineer is recommended
prior to the start of construction to discuss specific procedures and scheduling. 11823
Slauson Avenue, Unit 18, Santa Fe Springs, CA 90670; Phone: 562-945-0689; Fax: 562-945-0364
I
S & W Development Page 11 of 11
EGL Project No.: 99-181-006EG August 30, 1999
12.0 INVESTIGATION LIMITATIONS
The materials encountered on the subject site and utilized in our laboratory testing program are
believed to be representative of the area. However, soil materials may vary in characteristics
between excavations. Since our investigation is based on the site materials observed, selected
laboratory testing, and engineering analyses, the conclusions and recommendations are
professional opinion. These opinions have been derived in accordance with current standard of
practice, and no warranty is expressed or implied.
i
11823 Slauson Avenue, Unit 18, Santa Fe Springs, GA 90670; Phone: 562-945-0689; Fax: 562-945-0364
APPENDIX A
FIELD INVESTIGATION
Subsurface conditions were explored by excavating three test pits to a maximum depth of 4 feet
at approximate locations shown on the enclosed Site Plan, Figure 2.
The excavating of the test pits were supervised by an EGL geotechnical engineer and an
engineering geologist, who continuously logged the test pits and visually classified the soils in
accordance with the Unified Soil Classification System. Ring samples were taken at frequent
intervals. These samples were obtained by driving a ring sampler with successive blows of 32-
pound hammer dropping from a height of 48 inches.
Representative undisturbed samples of the subsurface soils were retained in a series of brass
rings, each having an inside diameter of 2.42 inches and a height of 1.00 inch. All ring samples
were transported to our laboratory. Bulk surface soil samples were also collected for additional
classification and testing.
APPENDIX B
LABORATORY TESTING
During the subsurface exploration, EGL personnel collected relatively undisturbed ring samples
and bulk samples. The following tests were performed on selected soil samples:
Moisture -Density
The moisture content and dry unit weight were determined for each relatively undisturbed soil
sample obtained in the test borings in accordance with ASTM D2937 standard. The results of
these tests are shown on the boring logs in Appendix A.
Shear Tests
Shear tests were performed in- a direct shear machine of strain -control type in accordance with
ASTM D3080 standard. The rate of deformation was 0.025 inch per minute. Selected samples
were sheared under varying confining loads in order to determine the Coulomb shear strength
parameters: internal friction angle and cohesion. The shear test results are presented in the
attached plates.
Consolidation Tests
Consolidation tests were performed on selected undisturbed soil samples in accordance with
ASTM D2435 standard. The consolidation apparatus is designed for an one -inch high soil filled
brass ring. Loads are applied in several increments in a geometric progression and the
resulting deformations are recorded at selected time intervals. Porous stones are placed in
contact with the top and bottom of each specimen to permit addition and release of pore fluid.
Inundation of samples were performed at a load of one kip per square foot, and the test results
are shown on the attached Figures.
Corrosion Potential
Chemical ,laboratory tests were conducted on the existing onsite near surface materials sampled
during EGL's field investigation to aid in evaluation of soil corrosion potential and the attack on
concrete by sulfate soils. These tests are performed in accordance with California Test Method
417, 422, 532, and 643. The testing results are presented below:
Chloride Sulfate Min, Resistivity
Sample Location PH (ppm) (% by weight) (ohm/cm)
0.004 1010
T-2 Cad 0-3' 7.87 130
EGL TEST PIT LOG T-3
DATE QRILLIED: E18-09.99
PROJECT LrQCATION: 2501 Crowfoot Lane, Diamond Bar, California SAMPLE METHOD: Hand r
PROJECT NO: 99-18 EG ELEVA nON: NIA
LOGGED BY: JL
Sample
o S: Standard Penetration Test
R: Fling Sample
Y o Description of Material
a Ca a m
76.3 18.7
Puente Formation: medium to yellowish brown, moist to very moist, stiff to hard, weatherR75Siltysandstone,
@ 3 feet, Bedding N6 E, Wt
R 100 0.3 21.6
1911
5
Total Depth 4 feet
i No Ground Water
Hole Backfilled
Hat-ner Driving Weight: 32 lbs
Hammer Drop Height: 48 inches
1aping
i
iss
PLATE A-1
EGL TEST PIT LOG T-1
PROJECT LOCATION: 2501 Crowfoot Lane, Diamond Bar, California
PROJECT NO: 99-181-006EG
Sample
O S: Standard Penetration Test
cj R: Ring Sample
DATE DRI LLI ED: 08-09-99
SAMPLE METHOD: Hand Sampler
ELEVATION: NIA
LOGGED BY: JL
gR
L) An
0 g a o Description of Material
2
Slopewash: Silty clay, medium to dark brown, slightly moist, soft, few fine roots
78.9 9.3 Puente Formation: Slltstone, medium to yellowish brown, moist, stiff to hard, weathered
@ 2.5 feet, Bedding WE, E14
5
Total Depth 3 feet
No Ground Water
Hole Backfilled
Hammer Driving Weight: 32 lbs
Hammer Dropping Height: 48 inches
10
1
35
PLATE A-1
0 500 1000 1500 2000 2500 3000 3500 4000
NORMAL PRESSURE (PSF)
BOREHOLE
SYMBOL NUMBER
T-1
A
LEGEND
Peak Shear Strength
A Reshear Shear Strength
SAMPLE DEPTH SAMPLE SOIL COHESION
TYPE (PSF) p,ARjGION
NUMBER (
FT) TYPE 460
26 NIA
2.0 RING ML 820
26 ENVARONMENTAL
Project
Address! GEOTECHAVOLOGY
2501 Crovufoot Lane LABORATORY
Diamond Bar, California DIRECT
SHEAR ASTM
D3080) FIGURE
u-
o-
U)
uJ
H
Q
W
0 500 1000 1500 2000 2500 3000 35UU Liu00
NORMAL PRESSURE (PSE)
BOREHOLE SAMPLE DEPTH SAMPLE
TYPE
SOIL I COHESION ANGLE (DEG)
SYMBOL NUMBER NUMBER (FT)
90 32
3.0 RING ML
T-2 NIA 240 30
0
ENVIRONMENTAL
Project Address:
GEOTECHNOLOGY 2501 Crowfoot Lane
LABORATORY Diamond Bar, California
LEGEND
Peak Shear Strength DIRECT SHEAR
o Reshear Shear Strength (ASTM D3080)
FIGURE
0 500 1000 1500 2000 2500 3000 35OU 4U00
NORMAL PRESSURE (PSF)
BOREHOLE SAMPLE DEPTH SIMPLE
TYPE
SOIL CO{
PSF)
HESION ANGLEO( DEG)
SYMBOL NUMBER NUMBER (FT)
70 42
1.0 RING ML
T_3 NIA 150 36
0
ENVIRONMENTAL
project Address:
GEOTECHNOLOGY 2501 Crowfoot Lane
LABORATORY Diamond Bar, California
LEGEND
Peak shear Strength DIRECT SHEAR
o Reshear Shear Strength (ASTM D3080)
FIGURE
SYMBOL BORING SAqNO EPTH SOIL INIT. MOISTURE INIT. DRY INIT. VOID
NO TYPE CONTENT DENSITY RAT70
PCBN3.0 ML 21.6 81.6 1.064
Project Address:
Bnvironmental
eotechno10gy 2501 Crowfoot
Diamond Bar, CaliforniaLaboratory
CONSOLIDATION
ASTM D2435)
FIGURE
1 8/99
GEOTECIINICAL REVIEW SHEET
LEIGHTON AND ASSOCIATES, INC.
FOR
CITY OF DIAMOND BAR
DEPARTMENT OF ENGINEERING
2910164-134
Tract(s) Lot 61. Tract 23483 Date March 21, 2000
Parent Tract Location/Owner
Site Address 2501 Crow Foot Lane
Geologist Environmental Geotechnical Laboratory Developer
Soils Engineer Environmental Geotechnical Labojggg Engineer/Arch.
REVIEW OF:
Grading P.C. No.
Geologist Report(s) Dated
Soils Report(s) Dated
X Geology and Soils Report(s) Dated August 30, 1999 -m-
X Other Grading and Drainage Plan dated Februa 16 2000
Previous Submittals Dated
ACTION:
Plan/Report is geotechnically approved
Plan/Report is geotechnically approved
subject to conditions below.
REVIEW COMMENTS:
X Plan/Reportnot approved for reasons below X
Submit Plan/Report for recheck. Include a cony
of this review. 1.
Shallow test pits (3 to 4 feet in depth exposing a maximum depth of 2 feet of bedrock) are insufficient to evaluate
the bedrock conditions underlying the site. Deeper geologic data must be obtained to evaluate the geologic
and slope stability conditions. 2.
The geologic cross-section must be shown on the Site Geology Plan. The geologic cross-section must be appropriately
labeled and. include the subsurface data and the proposed structures. The section must be extended
beyond the property line, to include slopes above or below the property limits.
2910164-134
3, The geotechnical consultant should review unpublished and published geotechnical maps and reports from
appropriate sources to further evaluate the site conditions. In addition, aerial photographs of the site should
be reviewed to evaluate site geologic conditions. Reference all material reviewed.
4. The geologic map and cross-section indicate that adversely oriented bedding planes may be present beneath
the slopes onsite. Stability analysis of these slopes must be provided. The consultant must review the need
for subdrainage behind slope stability fills.
5. Provide specific recommendations for the construction of the recommended retaining wall subdrain system.
6. The geotechnical consultants must review foundation and retaining wall plans and provide appropriate
recommendations.
7. Provide Expansion Index test results for the site. Foundations in expansive soils must be designed in
accordance with Section 1815 or 1816 of the current UBC.
S. All remedial measures (keys, estimated removal depths, etc.) must be shown on the grading plan. The
grading plan must include a cut/fill line. The notes on the grading plan must be updated to current standards
Note 18, Section 111 Statement).
9. Both the Soils Engineer and the Engineering Geologist must sign the grading plan indicating they have
reviewed the plans from a geotechnical viewpoint.
Reviewed by __ _Date March 21 2000
David C. Smith
Reviewed by Date March 2I 2000
Philip A. Buchiarelli
2 MIS MUM
21660 EAST COPLEY DRIVE, SUITE 100
DIAMOND BAR, CA 91765-4177
909-860-2489 9 FAX 909-861-3117
COMMUNITY & DEVELOPMENT SERVICES DEPARTMENT
LETTER OF TRANSMITTAL
TO: Leighton & Associates
WE ARE SENDING YOU: Attached
Shop drawings
X Copy of Letter
Prints
DATE: 3/2/00 JOB NO.: G-00-407
ATTENTION: David Smith
RE: 2501 CROW FOOT LN.
Under separate cover via the following items.
Plans Samples
Change Order X Other Report
COPIES DATE NO, DESCRIPTION
1 8/25/99 Grading & Drainage Plan
1 8/30/99 Report of Geotechnical and Geological Investigation...
THESE ARE TRANSMITTED as checked below:
For approval
For your use
As requested
X Review/comment
FOR BIDS DUE
Approved as submitted
Approved as noted
Returned for corrections
Other (see remarks)
Resubmit — copies for approval
Submit — copies for distribution
Return corrected prints
PRINTS RETURNED AFTER LOAN TO US
REMARKS: IS` Sub. P.O. in process. P.O. not-to-excded $1640 00
Specs.
Jahn L. Basin,
COPY TO: FILE SIGNED: Engineering T.. cian