0108-293 (ELEC) Geotechnical InvestigationGL OBA L GEO-E/V0//VEEM1JVG, //VC.
o2wireless Solutions
8300 Utica Avenue, Suite 245
Rancho Cucamonga, California 91730
Attention: Mr. Arthur Hayes
Construction Manager
Subject: Geotechnical Investigation
Verizon Wireless Site: La Quinta
State Highway I I I & Washington Street
La Quinta, California
References: (See Appendix A)
Dear Mr. Hayes:
1. INTRODUCTION
a) In accordance with your request, we have conducted a geotechnical investigation for the
proposed wireless development at the project location referenced above.
b) We understand that the proposed improvements will consist of installation of a new 65-
foot high monopalm cellular antenna and a new 12-foot by 20-foot equipment shelter.
c) This development will be utilized for wireless transmission and will not be inhabited.
d) The project plans, consisting of half size unsigned sheets prepared by Velocitel Inc.,
were provided to us and generally depict the proposed development and general
conditions of the Property.
CITY OF LA GUINTA
BUILDING & SAFETY DEPT.
APPROVED
FOR CONSTRUCT SON
U
DATE BY
2712 Dow Avenue, Suite B, Tustin California 92780
Office (714) 505-8040 Fax (714) 505-8043
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July 16, 2001
Project 1057-04
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2: SCOPE
The scope of services we provided is as follows:
a) Preliminary planning and preparation;
b) Review of available geotechnical reports and maps pertaining to the property;
c) Field exploration consisting of drilling one boring to a depth of 30 feet, using a
truck -mounted, 8-inch diameter, hollow -stem auger drill rig;
d) Obtaining in -situ and bulk samples for classification and laboratory testing;
e) Laboratory testing of selected samples considered representative of site conditioning
in order derive relevant engineering properties;
f) Geological and engineering analyses of the field and laboratory data;
g) Preparation of a final geotechnical report presenting our findings, conclusions and
recommendations pertaining to:
i) grading;
ii) processing of soils;
iii) foundation type(s);
iv) foundation depths;
v) bearing capacity;
vi) expansivity;
vii) corrosivity;
viii) resistivity;
ix) sulphate and chloride content and cement type;
x) shrinkage factor, subsidence;
xi) slabs -on -grade;
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Project 1057-04
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xii) settlement;
xiii) retaining walls (if proposed in the future):
• active pressure;
• at -rest pressure;
• passive resistance;
• coefficient of friction;
xiv) seismic characteristics;
xv) drainage and ground water;
xvi) liquefaction.
3. FIELD EXPLORATION
The field exploration program is given in Appendix B, which includes the Log of Boring.
4. LABORATORY TESTING
A description of the laboratory testing and the results is presented in Appendix C.
5. SITE DESCRIPTION
5.1 Location
a) The subject site is located north of Highway 111 approximately midway
between Washington Street and Adam Street in the City of La Quinta,
California. More specifically, the proposed development area is situated at
the northeastern corner of Coachella Valley Water District (CVWD) Well
Site No. 5712, which is located at the rear of an existing retail center. The
CVWD Whitewater Storm Channel exists approximately 50 feet north of the
subject site.
b) The approximate site location is shown on the Location Map, Figure 1.
5.2 Surface Conditions
a) The CVWD well site, which is enclosed by a 5+ foot high masonry block
wall and gate, is currently occupied by a 10 foot by 10 foot well house, an
above ground storage tank, a transformer and a few sheds.
LOCATIONMAP
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BASE MAP: USGS 7.5 Minute Topographic Map,
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La Quinta Quadrangle, 1980
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SCALE FEET
State Highway 111 and Washington Street
.JIMGLOBAL GEO-ENGINEERING, INC. La Quinta, California
GEOLOGIC AND SOILS ENGINEERING TUSTIN, CALIFORNIA Date: July 2001 Figure No:
Project No.: 1057-04 1
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July 16, 2001
Project 1057-04
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b) The well site pad is flat, but elevated approximately 1-2 feet above the
surrounding adjacent ground surfaces. The topography of the surrounding
area is relatively flat with a slight gradient to the southeast. Vegetation
within the proposed development area consists of scattered weeds and two
palm trees.
c) Drainage at the site consists of sheet flow run-off of incident rainfall derived
from within the property boundaries and surrounding up -gradient areas.
Surface drainage within the site area is predominantly to the southeast
toward the Salton Sea.
5.3 Geolo
5.3.1 Regional Geologic Setting
The project site is situated within the Peninsular Ranges Geomorphic
Province in Southern California. Geologic structures within this province are
characterized by a northwest -trending topographic range that terminates
directly against the Transverse Ranges to the north. The inland portions of
the province include several high mountain ranges, underlain by igneous,
metasedimentary, and metavolcanic rock of the Paleozoic and Mesozoic age.
The coastal portion is defined by clastic marine and non -marine terraces of
the upper Cretaceous, Tertiary, and Quaternary age. Structurally, the
province is regarded as an uplifted and westward tilted range, which has
been faulted and broken up into several smaller sub -parallel blocks. The
Peninsular Ranges province is both bounded and transected by several major
fault zones. Principal faults include the San Andreas, San Jacinto, Newport -
Inglewood and the Whittier -Elsinore Fault Zones.
5.3.2 Local Geologic Setting
In general, the project site area is underlain by recent -aged alluvium.
J5.4 Subsurface Conditions
5.4.1 Fill
a) Fill soils were encountered in the upper six feet of our drilled excavation.
I
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July 16, 2001
Project 1057-04
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5.4.2 Alluvium
a) Recent -aged alluvial soils, consisting of SAND and Sandy SILT, was
encountered below the fill to the maximum explored depth of 30 feet.
b) The SAND exposed in our exploration was generally observed to be
fine grained, tan to light brown, dry to slightly moist, and loose to
medium dense.
l c) A thin layer of Sandy SILT, encountered at a depth of 17 feet below
I ground surface, was found to be light brown, slightly moist and
medium stiff.
5.4.2 Groundwater
No groundwater or seepage was encountered in our boring during the course
of this investigation.
6. POTENTIAL SEISMIC HAZARDS
6.1 General
a) The property is located in the general proximity of several active and
potentially active faults, which are typical for sites in the Southern California
region. Earthquakes occurring on active faults within a 70-mile radius are
capable of generating ground shaking of engineering significance to the
proposed construction.
b) In Southern California, most of the seismic damage to manmade structures
results from ground shaking and, to a lesser degree, from liquefaction and
ground rupture caused by earthquakes along active fault zones. In general,
the greater the magnitude of the earthquake, the greater the potential damage.
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6.2 Ground Surface Rupture
The Property is not within an Alquist-Priolo Special Studies Zone; however, during
historic times, a number of major earthquakes have occurred along active faults in
Southern California. The closest active fault is the San Andreas Fault, located at a
distance of about 5.4 miles northeast of the project site. Other active faults include
the San Jacinto and Landers Faults, located at distances of about 21 and 32 miles,
respectively, from the Property. Due to the distance of the closest active fault to the
site, ground rupture is not considered a significant hazard at the site.
6.3 Deterministic Seismic Hazard Analysis
a) We performed a deterministic seismic hazard analysis using the computer
program EQFAULT, EQSEARCH, and UCSEIS (Blake, 2000). The
program computes the peak ground acceleration and the maximum
magnitude earthquakes on each of the faults found within a user specified
radius. The computation of the peak acceleration is based on the closest
distance between the site and each digitized fault and a user specified
attenuation relationship. For our analysis, we used a 70-mile radius and the
attenuation relationships developed by Boore, et al, (1997). Peak ground
acceleration for the Property is 0.43g.
b) Figure 2 shows the geographical relationships among the site locations,
nearby faults and the epicenters of significant occurrences. Figure 3 gives
the seismic parameters affecting the subject site. The project site is not
located within any Alquist-Priolo Fault Zone; however, during historic
times, a number of major earthquakes have occurred along the active faults
in Southern California. From the seismic history of the region and
proximity, the San Andreas Fault has the greatest potential for causing
earthquake damage related to ground shaking at this site.
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-7. LIQUEFACTION
a) Liquefaction is the phenomenon where saturated soils develop high pore water
pressures during seismic shaking and behave like a fluid. This phenomenon
generally occurs in coastal areas of high seismicity, where ground water is shallow
and loose granular soils or hydraulic fill soils subject to liquefaction are present.
Liquefaction events may be manifested by formation of sand boils and mud spouts at
the ground surface, seepage of water through cracks in the ground and quicksand -
like conditions over large areas. For liquefaction to develop loose granular soils
below the ground water table need to be present and shaking of sufficient magnitude
and duration must occur. When liquefaction does occur, the surface structures may
settle in to the ground or tilt excessively or significant settlement of the structures
may occur.
b) A qualitative evaluation of liquefaction potential was not performed, as part of this
study, because no structures for human occupancy are proposed for the subject
development and no ground water was encountered within the upper 30 feet of the
surface. The potential for liquefaction is considered to be nil.
8. CONCLUSIONS AND RECOMMENDATIONS
8.1 General
a) It is our opinion that the site will be suitable for the proposed cellular
development from a geotechnical aspect, assuming that our
recommendations are incorporated in the project plan designs and
specifications, and are implemented during construction.
b) We are of the opinion that the monopalm antenna tower can be supported on
a drilled cast -in -place caisson and the shelter foundations may be supported
on competent fill soils.
c) We are also of the opinion that with due and reasonable precautions, the
required grading will not endanger adjacent property nor will grading be
affected adversely by adjoining property.
d) The design recommendations in the report should be reviewed during the
grading phase when soil conditions in the excavations become exposed.
e) The final grading plans and foundation plans/design loads should be
reviewed by the Soil Engineer.
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Rage 8
1 8.2 Gradinn
8.2.1 Processing -of On -Site Soils
a) The subgrade soils are not considered adequate as foundation
material and should not be overexcavated to a depth of 2 feet below
the footings and extending laterally for a distance of 2 foot beyond
the edges of the footings.
b) Wherever structural fills are to be placed, the upper 6 to 8 inches of
the subgrade should, after stripping or overexcavation, first be
scarified and reworked.
c) The slab -on -grades and pavement should be underlain by at least 12
inches of compacted fill.
d) Any loosening of reworked or native material, consequent to the
passage of construction traffic, weathering, etc., should be made
good prior to further construction.
_ 1 e) The depths of overexcavation should be reviewed by the Soil
Engineer during construction. Any surface or subsurface
obstructions, or any variation of site materials or conditions
encountered during grading should be brought immediately to the
attention of the Soil Engineer for proper exposure, removal or
} processing, as directed. No underground obstructions or facilities
1 should remain in any structural areas. Depressions and/or cavities
created as a result of the removal of obstructions should be backfilled
properly with suitable materials, and compacted.
8.3 Material Selection
a) After the site has been stripped of any debris, vegetation and organic soils,
J excavated on -site soils are considered satisfactory for reuse in the
construction of on —site fills, with the following provisions:
i i) the organic content does not exceed 3 percent by volume;
ii) large size rocks greater than 8 inches in diameter should not be
incorporated in compacted fill;
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I Project 1057-04
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iii rocks eater than 4 inches in diameter should not be incorporated in
� IP
_l compacted fill to within 1 foot of the underside of the footings and
I slabs.
b) All imported fills, if used, should have very low -to -low expansion potential,
should have less than 20 percent passing through #200 sieve, should have
plasticity index of less than 15 and should be free of any organic and
deleterious matter.
8.4 Compaction Reuirements
a) Reworking/compaction shall include moisture-conditioning/drying as needed
to bring the soils to slightly above the optimum moisture content. All
reworked soils and structural fills should be densified to achieve at least 90
percent relative compaction with reference to laboratory compaction
standard. The optimum moisture content and maximum dry density should
be determined in the laboratory in accordance with ASTM Test Designation
D1557.
- 1 b) Fill should be compacted in lifts not exceeding 8 inches (loose). A sufficient
J number of field and laboratory compaction tests should be performed during
construction to verify minimum compaction requirements. Jetting of trench
backfill is not recommended.
8.5 Excavating Conditions
a) Excavation of on -site materials will require special considerations and will
require standard to heavy-duty earthmoving or trenching equipment.
b) Seepage and ground water were not encountered. Dewatering will not be
required.
8.6 Shrinka-ge
For preliminary earthwork calculations, an average shrinkage factor of 5 to 10
percent is recommended for the subgrade soils (this does not include handling
Jlosses).
8.7 Expan sivity
a) The expansion potential for existing on -site soils is considered to be Low by
observation. Any imported material or doubtful material exposed during
grading should be evaluated for expansivity.
I
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b) The soil expansion potential for specific areas should be determined during
the final stages of rough grading.
8.8 Sulphate Content
a) The sulphate content of a representative sample of the soil resulted less than
0.2%. This does not typify a high sulphate condition. However, Type V
Portland cement is recommended for the construction.
b) The fill materials should be tested for their sulphate content during the final
stage of rough grading.
8.9 Utility Trenching
a) The walls of temporary construction trenches in fill should stand nearly
vertical, with only minor sloughing, provided the total depth does not exceed
4 feet (approximately). Shoring of excavation walls or flattening of slopes
may be required, if greater depths are necessary.
b) Trenches should be located so as not to impair the bearing capacity or to
cause settlement under foundations. As a guide, trenches should be clear of
a 45-degree plane, extending outward and downward from the edge of
foundations.
` c) Existing soils may be utilized for trenching backfill, provided they are free of
organic materials.
d) All work associated with trench shoring must conform to the state and
federal safety codes.
8.10 Surface Drainage Provisions
J Positive surface gradients should be provided adjacent to the buildings to direct
surface water run-off away from structural foundations and to suitable discharge
facilities.
J
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8.11 Grading Control
1 All grading and earthwork should be performed under the observation of a Soil
Engineer in order to achieve proper subgrade preparation, selection of satisfactory
materials, placement and compaction of all structural fill and installation of piles.
Sufficient notification prior to stripping and earthwork construction is essential to
make certain that the work will be adequately observed and tested.
8.12 Slab -on -Grade
l a) Concrete floor slabs may be founded on the reworked existing soils or
compacted fill. The subgrade should be proof -rolled just prior to
construction to provide a firm, unyielding surface, especially if the surface
has been loosened by the passage of construction traffic.
b) If a floor covering that would be critically affected by moisture is to be used,
a plastic vapor barrier is recommended. This sheeting should be covered
with two inches of SAND.
c) It is recommended that #3 bars on 18-inch center, both ways, be provided as
minimum reinforcement in slabs -on -grade. Joints should be provided and
slabs should be at least 4 inches thick.
d) Use a modulus of subgrade reaction of 150 lb/in3-
e) The FFL should be at least 6 inches above highest adjacent grade.
8.13 Spread Foundations
The proposed structures can be founded on shallow spread footings. The criteria
presented as follows should be adopted:
8.13.1 Dimensions/Embedment Depths
Number of Stories
Minimum Width
Minimum Footing
Minimum Embedment
(floors supported)
(ft.)
Thickness
Below Lowest Adjacent
(in.)
Finished Surface (ft.)
1
1.0
6
1.5
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8.13.2 Allowable Bearing Ca aci
Embedment Depth
(ft.)
Allowable Bearing Capacity
(Ib/A )
1.5
1,800
(Notes:
I • These values may be increased by one-third in the case of short -duration
loads, such as induced by wind or seismic forces.
• At least 2x#4 bars should be provided in wall footings, one on top and one at
the bottom.
• In the event that footings are founded in structural fills consisting of
imported materials, the allowable bearing capacities will depend on the type
1 of these materials, and should be re-evaluated.
• Bearing capacities should be re-evaluated when loads have been obtained
and footings sized during the preliminary design.
• Planter areas should not be sited adjacent to walls.
• Footing excavations should be observed by the Soil Engineer.
• It should be insured that the embedment depths do not become reduced or
adversely affected by erosion, softening, planting, digging, etc.
8.13.3 Settlements
Total and differential settlements under spread footings are expected to be
within tolerable limits and are not expected to exceed'/4 and''/z inches,
respectively.
8.14 Deep Foundations
a) It is anticipated that the monopole will be supported on a deepened
foundation system consisting of a cast —in -place caisson pile, founded into
competent native soils. It is estimated that the minimum diameter of the
caisson will be 36-inches.
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b) Caving of the exploratory boring did occur during the subsurface
exploration. Special provisions should be taken into account during the
drilling process of the caisson to mitigate the effects of caving.
c) If required, specific pile dimensions, recommendations and other
construction related procedures will be provided when design loads have
been finalized by others.
8.15 Lateral Pressures
a) The following lateral pressures are recommended for the design of retaining
structures.
Pressure (lb/ft2/ft depth)
Lateral Force
Soil Profile
Unrestrained
Rigidly Supported
Wall
Wall
Active Pressure
Level
38
-
At -Rest Pressure
Level
-
65
Passive Resistance
Level
300
-
(ignore upper 1.5 ft.)
b) Friction coefficient: 0.35 (includes a Factor of Safety of 1.5).
c) These values apply to the existing soil, and to compacted backfill generated
from in -situ material. Imported material should be evaluated separately. It is
recommended that where feasible, imported granular backfill be utilized, for
a width equal to approximately one -quarter the wall height, and not less than
1.5 feet.
d) Backfill should be placed under engineering control.
e) Subdrains should be provided behind retaining walls.
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8.16 Seismic Coefficient
For seismic analysis of the proposed regeneration project in accordance with the
seismic provisions of UBC 1997, we recommend the following:
ITEM
VALUE
REFERENCE
Soil Profile Type
Sd
UBC Table 16J
Seismic Source Type
A
UBC Table 16U
Near Source Factor-Na
1.1
UBC Table 16S
Near Source Factor-N
1.3
UBC Table 16T
Seismic Coefficient -Ca
0.46
UBC Table 16Q
Seismic Coefficient-C
0.83
UBC Table 16R
Peak Ground Acceleration
0.43g
EQFAULT (Blake 1999)
8.17 Soil Corrosivity
a) Sulfate and chloride tests were performed on one sample of the near -surface
materials. The results of the tests indicate water-soluble sulfate content of
0.052% and chlorides of 0.031 %, suggesting that sulfate and chloride attack
hazard is low for the near -surface soils. Type V cement and a water to
cement ratio of 0.5 would be appropriate for design of the concrete slab -on -
grade.
b) The minimum electrical resistivity of the near -surface soils is less than 200
ohm -cm. To evaluate the corrosion potential of near -surface soils, we used
the following correlation between electrical resistivity and corrosion
potential:
Electrical Resistivity. ohm -cm
Corrosion Potential
Less than 1,000 Severe
J 1,000 to 2,000 Corrosive
2,000 to 10,000 Moderate
Greater than 10,000 Mild
lc) Based on these data, it is our opinion that general onsite near -surface soils
have a severely corrosive potential for buried metal. This potential should be
considered in the design of any underground metal utilities. Sulfate and
corrosivity test results are presented in Appendix C.
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1 9. LIMITATIONS
a) Soils and bedrock over an area show variations in geological structure, type, strength
and other properties from what can be observed, sampled and tested from specimens
-� extracted from necessarily limited exploratory borings. Therefore, there are natural
limitations inherent in making geologic and soil engineering studies and analyses.
Our findings, interpretations, analyses and recommendations are based on
observation, laboratory data and our professional experience; and the projections we
make are professional judgments conforming to the usual standards of the
profession. No other warranty is herein expressed or implied.
b) In the event that during construction, conditions are exposed which are significantly
different from those described in this report, they should be brought to the attention
of the Soil Engineer.
The opportunity to be of service is sincerely appreciated. If you have any questions or if we can be
of further assistance, please call.
Very truly yours,
GLOBAL GEO-ENGINEERING,
KA1r,
Mohan B. pasani
Principal Geotechnical E
RGE 2301
(Exp. March 31, 2003)
-A MBU/KBY:kby/dd
JEnclosures:
Location Map
References
Field Exploration
Unified Soils Classification System
Boring Location Plan
Log of Boring
Laboratory Testing
J
c
eevin B. Youn
Principal Geologist
RG 7225
(Exp. October 31, 2003)
- Figure 1
- Appendix A
- Appendix B
Figure B-1
Figure B-2
Figure B-3
- Appendix C
Project 1057-04
APPENDIX A
References
1. Blake, T. F., 1989, (Updated 2000) "EQFAULT: A Computer Program for the
Deterministic Prediction of Peak Horizontal Acceleration from Digitized California Fault, "
User Manual and Program;
2. Blake, T. F., 1989, (Updated 1999) "EQSEARCH.• A Computer Program for the Estimation
of Peak Horizontal Acceleration from California Historical Earthquake Catalogs, " User
Manual and Program;
3. Blake, T.F., 1999, UBCSEIS, 2000, "A Computer Program for the Estimation of Uniform
Building Code Coefficients Using 3-D Fault Sources ", User Manual and Program, 53p;
4. Boore, D.M., Joyner, W.B., and Fumal, T.E., 1997, "Equations for the Estimating
Horizontal Response Spectra and Peak Acceleration from Western North American
Earthquakes: A Summary of Recent Work": Seismological Research Letters, Vol. 68, No. 1,
pp. 128-153;
5. California Department of Water Resources, July 1964, "Coachella Valley Investigation",
Bulletin No. 108;
6. Greensfelder, Roger W., 1974, `Maximum Credible Rock Acceleration from Earthquakes in
California": California Division of Mines and Geology, M. S. 23, (explanation 12 pages);
7. United States Geological Survey, 1980, 7.5-Minute Topographic Map, La Quinta
Quadrangle.
Project 1057-04
• APPENDIX B
Field Exploration
a) The site was explored on June 29, 2001 utilizing an 8-inch diameter truck -mounted, B-53
hollow stem auger drill rig, to excavate one boring to a maximum depth of 30 feet below the
l existing ground surface. The boring was subsequently backfilled.
J b) The soils encountered in the boring was logged and sampled by our Engineering Geologist.
The soils were classified in accordance with the Unified Soil Classification System
described in Figure B-1. The approximate location of the boring is shown on the Boring
Location Plan, Figure B-2. The Log of Boring for this investigation is presented in Figure
B-3. The log, as presented, is based on the field log, modified as required from the results of
the laboratory tests. Driven ring and bulk samples were obtained from the excavations for
laboratory inspection and testing. The depths at which the samples were obtained are
indicated on the logs.
c) The number of blows of the hammer during sampling was recorded, together with the depth
of penetration, the driving weight and the height of fall. The blows required per foot of
penetration for given samples are indicated on the logs. These blow counts provide a
] measure of the density and consistency of the soil.
d) No groundwater or seepage was encountered within the drilled boring.
e) Minor caving did occur as indicated on the log.
UNIFIED SOILS CLASSIFICATION (ASTM D-2487)
PRIMARY DIVISION
GROUP SYMBOL I SECONDARY DIVISIONS
w
Clean
GW
Well graded gravels, gravel -sand mixture, little or no fines
W N
N .N
L m >
w `—N° '°—°,'
Gravels
(<5% ones)
GP
Poorly graded gravels or gravel -sand mixtures, little or no fines
`0 _
! m a
i r o v
.. c
a) 2 .o c
Gravel with
GM
Silty gravels, gravel -sand -silt mixture. Non -plastic fines.
LUE'w
Z -
C7`o°i��
g -
Fines
o o
`�
GC
Clayey gravels, gravel -sand -clay mixtures. Plastic fines
m
O L `
m
m w c
Clean Sands
SW
Well -graded gravels, gravel -sand mixtures, little or no fines.
rwn L -
-- aD
0 E2 �' r >
m m o .?
(<5% fines)
SP
Poorly graded sands or gravelly sands, little or no fines.
< 21
OU `—°
Z L U U 0 N
o o ca E
Sands with
SM
Silty sands, sand -silt mixtures. Non -Plastic fines.
Fines
SC
Clayey sands, sand -clay mixtures. Plastic fines.
o
t- ¢
ML
Inorganic silts and very fine sands, rock flour, silty or clayey fine
N
Z U)
=
sands or clayey silts, with slight plasticity
U) •F U5
rn }
o
CL
Inorganic clays of low to medium plasticity, gravelly clays, sandy
O >
� U
5 w
clays, silt clays, lean clays.
OL
Organic silts and organic silty clays of low plasticity.
� N'�
E u
�oLU
C3J
� co
—
Z ° N
H 0_
MH
Inorganic silts, micaceous or diatomaceous fine sandy or silty
L
o
Q }
¢ Lb
soils, elastic silts.
CH
Inorganic clays of high plasticity, fat clays
CO co w
rn o w <
Z
_1U
o��
LL o
E
OH
Organic clays of medium to high plasticity, organic silts.
0
Highly Organic Soils
PT
Peat and other highly organic soils.
CLASSIFICATION BASED ON FIELD TESTS
Clays and Silts .
PENETRATION RESISTANCE (PR)
'Numbers of blows of 140 lb hammer
Sands and
Gravels
Consistency
Blows/foot' Strength—
falling 30 inches to drive a 2-inch O.D.
(1 3/8 in, I.D.) Split Barrel sampler
(ASTM-1568 Standard Penetration Test)
Relative Density
Blows/foot
Very Soft
0-2 0-'/2
Very loose
0-4
Soft
2-4
'/.--'/z
Loose
4-10
Firm
4-8
'/r1
"Unconfined Compressive strength in
Medium
Dense
10-30
Stiff
8-15
J 1-2
tons/sq. ft Read from pocket
Dense
30-50
Very Stiff
15-30
2-4
penetrometer
Very
Dense
Over 50
Hard
Over 30
Over 4
CLASSIFICATION CRITERIA BASED ON LAB TESTS
60
GW and SW — C.= D6o/D,o greater than 4 for GW and 6 for SW; C°= (D30) 2/D,ox D6o
between 1 and 3
so
x
30
GP and SP — Clean gravel or sand not meeting requirement for GW and SW
Z30'
a 20
GM and SM — Atterberg limit below "A" line or P.I. less than 4
10
GC and SC — Atterberg limit above "A" line P.I. greater than 7
0
0 10
20 30 40 50
60 70 80 90
100 CLASSIFICATION OF EARTH MATERIAL IS BASED ON FIELD INSPECTION
Liquid Limit
AND SHOULD NOT BE CONSTRUED TO IMPLY LABORATORY ANALYSIS
Plasticity chart for laboratory
UNLESS SO STATED.
Classification of Fine-grained soils
Fines (Silty
or Clay)
Fine Sand Medium Sand Coarse Sand Fine Gravel Coarse Gravel Cobbles Boulders
Sieve Sizes 200
40
10 4 3/." 3" 10"
State Highway 111 and Washington Street
GEO-ENG/NEERING,
INC.
La Quinta, California
Date: July 2001
Figure No.:
GEOLOGIC AND SOILS ENGINEERING,
qMGLOBAL
TUSTIN, CALIFORNIA
, Project No.: 1057-04
B-1
BORING L O CA TION PLAN
ICE TAM Flo
o C �•�t
�i
C • ` \
r
� Dk .�
Dasmc ACCESS 1 : ti -, 7; ■
CATES
s. Aa7fF CwE - 1 1•�'ti� ,. +•. ':. o.�
A _ Wit•-••'".---«•.•. ...-_-••_ .•__ _ l 1= .�� "�7`
...Y•,•\1 j�: f �•�'S•
p t MOND== 6"-0- INOE N.I. G1TE , :. � �,�5.';�' .`ti l4
■ `. \-� � ="�•
PROPOSED 0'
CPS ARIENIA EOGTION �1 : '►. F
,
./• G PROPOSED SSrU
S' TYPR'x OF Z. (TO K f
-•
B-1
YNNTAWED By rEnIIRq �:a; _ ?a
--EIST.G mG. Cm -
-�� f VAT" UME -
a
-PROPOSED a'-0
X TO MATCH ErS
-vnoPpsED ,� -
t r :f • � 514w
TO
R,
I • �• '--PROPOSED 20'
.�' AREA EW-IQSCD
� � • SLWP �,pCK x
.� = U.C.
PROPOSED 65'-0" mC
, •. xANTENNAS wOUNTED Q
-i y
"I�Lv.x.P
`' I
\J4
�
J .�',•
/E/ ROPO%E TO S+STCm AT EA
M'8E WIMiAp1E0 BY T
KEY
N
I3 1 O
Boring Location, showing total depth R
30'
30 0 30 60 T
H
SCALE FEET
State Highway 111 and Washington Street
GLOBAL GE I -ENGINEERING, INC.
La Quinta, California
Date: July 2001
GEOLOGIC AND SOILS ENGINEERING
TUSTIN, CALIFORNIA
Figure No:
Project No.: 1057-04
B-2
GLO@AL GEO-ENG/NEER/NG, INC.
GEOLOGIC! SOWS ENG-L,iCS}L,CwLIIOLIfA
Highway 111 and Washington
La Quinta, California
Project No. 1057-04
LOG OF TEST PIT B-1
Date
June 29, 2001
Logged By
KBY
Total Depth of Boring
. 30 feet
Diameter of Boring
8"
Drilling Company
Glodich Drilling
Drilling Rig
: B-53 HSA
Drilling Method
Hollow Stem Auger
Sampling Method
: Ring
Hammer Weight (lbs.)
: 140 lbs.
Hammer Drop (in.)
:30 in.
Depth to Groundwater
: None Encountered
Elevation
: -75 feet
N
°' L
T
rn
y
Depth
a)_
n
E
E
a o
o
3
r
v
DESCRIPTION
Feet
in
U)
o
��
o
m
O
D
0
0
Silty SAND/SAND: fine-grained, tan to light brown, dry to slightly
Bulk
moist, medium dense
Ring
1.9
103.6
30
SM/SP
5
Ring
1.8
82.8
67
FILL
j
SAND: fine-grained, tan to light brown, dry, loose to medium dense
®
Ring
N/R
N/R
18
10
®
Ring
66
99.1
12
SP
15—
® Ring 5.5 849 13
20
® Ring 1.0 90.2 21
25
30 II Ring I N/R I N/R 1 25
ML Sandy SILT: light brown, slightly moist, medium stiff
SAND: fine-grained, light brown, dry to slightly moist, medium dense
SP
ALLUVIUM
Bottom of Boring at 30 feet
Notes:
1) Caving to 25 feet
2) No Seepage or Groundwater Encountered
3) Boring backfilled and capped with AC patch
4) N/R - No Recovery
Figure B-3
Project 1057-04
APPENDIX C
Laboratory Testing Pro4ram
The laboratory testing program was directed towards providing quantitative data relating to the
relevant engineering properties of the soils. Samples representative of those obtained in the field
were tested as described below.
a) Moisture -Density
Moisture -density information usually provides a gross indication of soil consistency. Local
variations at the time of the investigation can be delineated, and a correlation obtained
between soils found on this site and nearby sites. The dry unit weights and field moisture
contents were determined for selected samples. The results are shown on the Log of Boring.
b) Compaction
A representative soil samples was tested in the laboratory to determine the maximum dry
density and optimum moisture content, using the ASTM D1557 compaction test method.
This test procedure requires 25 blows of a 10-pound hammer falling a height of 18 inches on
each of five layers, in a 1/30 cubic foot cylinder. The results of the test are presented below:
Sample Depth
Soil
Optimum Moisture
Maximum
Boring No.
(ft.)
Description
Content
o
Dry Density
( /o)
(Ib/ft�
B-1
0-3
Silty SAND/SAND
10.0
120.0
Appendix C
Project 1057-04
Page 19
c) Direct Shear
Direct shear tests were conducted on relatively undisturbed samples, using a direct shear
machine at a constant rate of strain. Variable normal or confining loads are applied
vertically and the soil shear strengths are obtained at these loads. The angle of internal
friction and the cohesion are then evaluated. The samples were tasted at saturated moisture
contents. The test results are shown in terms of the Coulomb shear strength parameters, as
shown below:
Angle of
FF
Sample Depth
Soil
Coulomb
Internal
Peak/
Boring No.
(ft.)
Description
Cohesion
(lb/ft')
Friction
(o
Residual
B-1
11
SAND
200 29
Peak
100 28
Residual
d) Sulfate Content
A representative soil sample was analyzed for their sulphate content in accordance with
California Test Method CA417. The results are given below:
Boring No.
Sample Depth
Soil
Sulphate
Content
(ft.)
Description
/o
B-1
0-3
Silty SAND/SAND
0.052
Appendix C
Project 1057-04
Page 20
e) Chloride Content
A representative soil sample was analyzed for chloride content in accordance with
California Test Method CA422. The results are given below:
Boring No.
Sample Depth
Soil
Chloride
Content
(ft.)
Description
B-1
0-3
Silty SAND/SAND
0.031
f) Resistivity
A representative soil sample was analyzed in accordance with California Test Method
CA643 to determine the minimum resistivity. The result is provided below:
Boring No.
Sample Depth
Soil
Minimum Resistivity
(ft.)
Description
(Ohm -cm)
B-1
0-3
Silty SAND/SAND
<200