Trilogy TR 30023 10-0310 (SFD) (Plans 4515, 4520, 5500) 2008 Energy Code Update - Geotechnical InvestigationiT
A
EaOth".. SliAtems
Southwest:
CITY OF LA QUINTA
BUILDING & SAFETY DEPT.
APPROVED
FOR CONSTRUCTION
DATE BY
Consu'lting Engineers a_nd.'Geii'olo`_gists'-
14 [010'
4
SHEA LA QUINTA, LLC
60-311 TRILOGY PARKWAY
LA QUINTA, CALIFORNIA 92253
;GEOTECHNICAL ENGINEERING REPORT
AND INFILTRATION TESTING FOR STORM
WATER RETENTION
TRAVERTINE PARCEL - TTM 3$996
WEST OF LIVING STONE DRIVE
LA QUINTA, CALIFORNIA
December 30, 2008
0.2008 Earth Systems Southwest
Unauthorized use or copying of this document is strictly prohibited
without the express written consent of Earth Systems Southwest.
File No.: 07711-31
Doc. No.: 08-12-769
Earth Systems
1� Southwest 79-811B Country Club Drive
Bermuda Dunes, CA 92203
(760)345-1588
(800)924-7015
FAX (760) 345-7315
December 30, 2008
Shea Homes La Quinta, LLC
60-3.11 Trilogy Parkway
La Quinta, California 92253
Attention
Project:
Subject:
Mr. Ulrich Sauerbrey
Travertine Parcel — TTM 35996
West of Living Stone Drive
La Quinta, California
File No.: 07711-31
Doc. No.: 08-12-769
Geotechnical Engineering Report and Infiltration Testing for Stormwater
Retention
We take pleasure in presenting this geotechnical engineering report prepared for the proposed 36-
Lot residential development to be located west of Living Stone Drive in the City of La Quinta,
Riverside County, California.
This report presents our findings and recommendations for site grading, foundation design
criteria, and retention basin/dry well -design, incorporating the information provided to our office.
The site is suitable for the proposed development, provided the recommendations in this report
are followed in design and construction. This report should .stand as a whole and no part of the
report should be excerpted or used to the exclusion of any other part.
This report completes our. scope of services in accordance with our agreement, dated October 29,
2008 and authorized on November 4, 2008. Other services that may be required, such as plan
review and grading observation, are additional services and will be billed according to our Fee
Schedule in effect at the time services are provided. Unless requested in writing, the client is
responsible for distributing this report to the appropriate governing agency or other members of
the design team.
We appreciate the opportunity to provide our professional services. Please contact our office if
there are any questions or comments concerning this report or its recommendations.
Respectfully submitted,
EARTH SYSTEMS SOUTHWEST
Joseph E. McKinney
GP 1052, PG 8249
SER/jem/csh/ajm
Distribution: 6/Shea La Quinta, LLC
2BD File
Reviewed
n
Craig S. F
CE 38234
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Exp. 03/31f t1' M
CIVIL ��\P
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TABLE OF CONTENTS
`
Page,
EXECUTIVESUMMARY
..........................................................................................................
ii
,Section I
l.|
m± rnU Description ----.---.----------_-------------_--.'l
� 1.2
Site ---.------^-------_-----------------.-1
13
Purpose and Scope ofServices -,-------.----.-------------.-..2
Smu�*n 2
�KETD�K�D�S�
2.1
Field Exploration ------------'--'.—.------------.`�----
4
2.2Testing'
� -
-,—.-_---_.^---_-------------------..'4
2.3
bdlbratknn Testing ---''.-----------------.-..'-----..-----'5
Section 3
DISCUSSION ............... ;.-_-'..--~..~-_..~'. ~~,..-.--'~~~
8
J]
SoUCwndidmno-.--_-------.----_------..-----^---^--8
32
Groundwater--_---^''------_--_—'--''^-------_�--'0
3'3
8���u� m�nm�� ............................................................................................................
8
3.4
Geologic Hazards ...........................................................................................................
9
3.4.1 Seismic Hazards ..................................... -----...... ----------_.g
3.42 Hazards .................................. ..................... ...............................
lO
3.43 Site Acceleration and Seismic Cmcffioients...................................................
ll
Section 4
...............................................
13
Section
RECOMMENDATIONS '
5]
Slope Stability ofGraded Slopes ............ '�---'----------.----._-
... l6
STRUCTURES .........................-------_-----'^-'--------------16
' 5.4
Foundations ....................................... .......................................... .................................
/6
�
5�
8\ubm��n-��ud� '
__________.___.___.____-.-------'---.l7
5.6
��Uu
Re�umo& ........................................... ................. ..............................................
lR
` 5.7
Mitigation of Soil Corrosivitypn Concrete .................................... ...........................
l0 .
5.8
Seismic Design Criteria ....................................................................... ....................... 2O
��
P�cm�� ____....
Section 6
LIMITATIONSAND ADDITIONAL SERVICES ................................................23
6.1
Uniformity of Conditions and Limitations ............................................ ........................ 23
8.2
Additional Services ---~------......... ........... r----'''.--.................
'-' 24
� x«EFxuxmmNCES_.-'..~.--..~^..--^...-.^^.,~-'^~.^,~'_~~_'-^^^`"-~~`^~---^..`^---^^^^^^---`^`^^'^'25
^ABPENDDXA `
Figure 1 -Qde Location
`
Figure 2-Boring and Infiltration Test Louudmon
Table 1-Fault Peounzetem
Terms and Symbols used onBoring Logs
Soil Classification System
Logs of Borings
Infiltration Test Results
Table 2-Initial Estimated Conductivities
APPENDIX `
Laboratory Test Results
EARTH 8YSTEMSSO0THWEST
I
EXECUTIVE SUMMARY
Earth Systems Southwest has prepared this executive summary solely to provide a general
overview of the report. The report itself should be relied upon for information about the
findings, conclusions, recommendations, and other concerns_
The site is located west of Living Stone Drive in the. Trilogy development in the City of La
Quinta, Riverside County, California. The proposed development will consist of about 36
residential lots that will include a collector street and two cul-de-sac streets. We understand that
the proposed structures will be one- or two -stories and will be of wood -frame and stucco
construction supported with perimeter wall foundations and concrete slabs -on -grade.
The proposed project may be constructed as planned, provided that the recommendations in this
report are incorporated in the final design and .construction. Site development will include
clearing and grubbing of vegetation, site grading, building pad preparation, underground utility
installation, street construction, and concretedriveway and sidewalks placement. Based on the
non -uniform nature and hydrocollapse potential of the near surface soils, remedial site grading is
recommended to provide uniform support for the foundations. Due to the presence of a
relatively shallow, collapsible dry -silt layer beneath the eastern half of the project site, special
foundation recommendations. are specified for lots in that area (see Section 5).
Laboratory testing of the site soils indicate low levels of sulfate and chloride ion content,
therefore normal concrete mixes may be used. However, indications are that the on -site soils
exhibit moderate to very severe. resistivity resulting in,a severe corrosion potential for buried
metal pipes. Underground utilities and buried metal pipes will require corrosion protection from
the surrounding soil.
We consider the most significant geologic hazard to the project to be the potential for moderate
to severe seismic shaking that is likely to occur during the design life of the proposed structures.
The project site is located in the highly seismic Southern California region within the influence
of several fault systems that are considered to be active or potentially active. Structures should
be designed in accordance with the values and parameters given within the 2007 California
.Building Code [CBC] and ASCE 7-05. :The seismic design parameters are presented. in the
following table and within the report.
EARTH SYSTEMS SOUTHWEST
SUMMARY OF RECOMMENDATIONS
Design Item
Recommended
• Parameter ;
Reference Section
No.
Foundations
Allowable Bearing Pressure '
Continuous wall footings
Pad Column footings
1,500 psf
2,000 psf
5.4
Foundation Type
Spread Footing
5.4
,Bearing Materials •
Engineered fill
Allowable Passive Pressure
350 psf per foot
5.4 and 5.6
Active Pressure
35 pcf
5.6
At -rest Pressure.
55 pcf
5.6
Allowable Coefficient of Friction
0.35
5.4
Soil Expansion Potential
Very low EI<20
3.1
Geologic and Seismic Hazards
Liquefaction Potential
Low
3.4.2
Si nificant .Fault and Magnitude
San Andreas, M7.7
3.4.1
Fault Type and Distance
A, l4.7 km
3.4.1
Seismic Design Category
D
5.8
Site Class
D
5.8
Maximum Considered Earth uake CE
Short Period Spectral Response, SS
1.50 g
5.8
Second S ectral'Res onse, Sj_
0. . 609
5.8
Site Coefficient, F,,
1.00
5.8
Site Coefficient, F,,
1.50 _
5.8
Pavement
TI equal to 5.0 (Light Traffic)
3.0" AC / 4.0" AB '
5.9
TI equal to 6.0 (Residential Streets)
3.5" AC / 4.0" AB
5.9
Slabs
Building Floor Slabs
On engineered fill
5.5
Modulus of Subgrade Reaction
200 pci
5.5
Existing Site Conditions
Existing Fill
N/A
Soil Corrosivity
low sulfates
low chlorides
very severe resistivity
5.7
Groundwater Depth
Present) >50-100 feet
3.2
Estimated Fill and Cut
excludes over -excavation
6 to 9 feet - cut
1.1.
The recommendations contained within this report are subject to the limitations presented in
Section 6 of this report. We recommend that all individuals using this report read the Limitations.
EARTH SYSTEMS SOUTHWEST
P
0
December 30, 2008
GEOTEC1 NICAL ENGINEERING REPORT
AND INFILTRATION TESTING FOR STORM
WATER RETENTION
TRAVERTINE PARCEL — TTM 35996
WEST OF LIVING STONE DRIVE
LA QUINTA, CALIFORNIA
Section 1
INTRODUCTION
1.1 Project Description
File No.: 07711.-31
Doc. No.:08-12-769
This geotechnical engineering report has been prepared for the Travertine Parcel of the Trilogy
Development located west of Living Stone Drive in the City of La Quinta, Riverside County,
California.
The proposed development will include about 36 residential lots that will include a collector
street and two, cul=de-sac streets. We understand that the proposed structures will be one- or
two -stories and will be of wood -frame and. concrete slab -on -grade construction with stucco .
exterior. We further understand the structures will. be supported by conventional shallow
continuous or pad footings.
Approximately 6 to 9 feet of native soil will be excavated and exported to lower the overall site
elevation. The removed soils will be exported to the. adjacent Tract 30023-6, Phase 6B and 6C.
Stormwater runoff and nuisance water will be managed with two retention basins: one thirteen -
foot deep basin located slightly east of the center of the parcel, and one nine -foot deep basin
located at the northeast corner. At least one MaxWellTM or equivalent dry -well system will be
installed in the bottom of each retention basin.
Site development will include clearing and grubbing of vegetation, site grading, building pad
preparation, underground utility installation, street construction, and concrete driveway and
sidewalks placement. Based on existing site topography and ground conditions, site grading is
expected to consist. of .and cuts of about 10 feet (excluding over -excavation and depth of
retention basins).
We used maximum column loads of 20 kips and a maximum wall loading of 2 kips per linear
foot as a basis for the foundation recommendations. All loading is assumed to be dead plus
actual live load. If actual structural loading exceeds these assumed values, we would need to
reevaluate the given recommendations.
1.2 Site Description
The proposed residential development is to be constructed on the Trilogy at Coral Mountain —
Tentative Tract Map No. 35996 development, to be located west of Living Stone Drive in the
City of La Quinta, Riverside County, California. The project site presently consists mostly of
native, undeveloped land. An approximately 20-foot wide by 1.5-foot deep temporary drainage
channel has been constructed along the north and east boundaries of the parcel. This channel
EARTH SYSTEMS SOUTHWEST
a
December 30, 2008 2 File No.: 07711-31
Doc. No.: 08-12-769
will be backfilled and compacted during grading. To the north and east are earlier phases of the
Trilogy development, to the east is an existing United States Bureau of Reclamation Levee,
approximately 32 feet high (this will be increased. as a result of grading and.will include a 10-
foot terrace). To the south is undeveloped, native land. The site location is shown on Figure t in
Appendix A.
The history of past use and development of the property was not investigated as part of our scope
of services. Other than the temporary drainage swale, no evidence of past -development was
observed on the site during our reconnaissance. Nonetheless, some.previous development of the
site is possible. Buried remnants, such as old .foundations, slabs, or septic systems, may exist on
the site
There may be underground utilities near and within the building area. These utility lines include,
but are not limitedto, domestic water, electric, sewer, telephone, :cable, 'and irrigation lines:
1.3 Purpose and Scope of Services
The purpose for our services was. to evaluate the site soil conditions and to provide professional
opinions and recommendations regarding the proposed development of the site. The scope of
work included the following:
➢ A general reconnaissance of the site.
➢ Shallow subsurface exploration by drilling 5 exploratory borings to depths ranging from
about 21..5 to 61.5 feet,below existing grade.
➢ Laboratory testing of selected soil samples obtained from the exploratory borings.
➢ A review of selected published technical literature pertaining to the site and previous
geotechnical reports prepared for earlier phases.of the'Trilogy development.
➢ An engineering analysis and evaluation of the acquired data from the exploration and
testing programs.
➢ A summary of our -findings and recommendations in this written report.
This report contains the following:
➢ , Discussions on subsurface soil and groundwater -conditions.
➢ Discussions on regional and local geologic conditions.
➢ 'Discussions on geologic and seismic hazards.
➢ Graphic and tabulated results of laboratory tests and field studies
➢ Recommendations regarding:
• Site development and grading criteria.,
• Excavation conditions and buried utility installations.
• Structure foundation type and design.
• Allowable foundation bearing capacity and expected
settlements.
• Concrete slabs -on -grade.
• Lateral earth pressures.and coefficients.
• .Mitigation 'of ' the potential corrosivity of site soils
reinforcement.
• Seismic design parameters. '
EARTH SYSTEMS SOUTHWEST
total and differential
to concrete and steel
December 30, 2008 3 File No.: 07711.-31
Doc. No.: 08-1.2-769
• Preliminary pavement structural sections.
Not Contained in This Report: Although available through Earth Systems Southwest, the current
scope of our services does not include:
➢ A corrosive study to determine cathodic protection of concrete or buried pipes.
,➢ An environmental assessment.
➢ An investigation for the presence or absence of wetlands, hazardous or toxic materials in
the soil, surface water, groundwater, or air on, below, or adjacent to the subject property.
The client did not direct ESSW to provide any service to investigate or detect the presence of
moisture, mold, or other biological contaminates in or around any structure, or any service that
was designed or intended to prevent or lower the risk or the occurrence of the amplification of
the same. Client acknowledges that mold is ubiquitous to the environment, with mold
amplification occurring when building materials are impacted by moisture.. Client further
acknowledges that site conditions are outside of ESSW's control and that mold amplification
will likely occur or continue to occur in the presence of moisture. As such, ESSW cannot and
shall not be held responsible for the occurrence or recurrence of mold amplification.
EARTH SYSTEMS SOUTHWEST
December 30, 2008
Section 2
METHODS OF INVESTIGATION
2.1_ Field Exploration
4 File No.: 07711-31
Doc. No.: 08-12-769
Five exploratory borings were drilled to depths ranging from about 21.5 to 61.5 feet below the
existing ground surface to observe the soil profile and to obtain samples for laboratory testing.
The borings were drilled. on November 19 and 20, 2008 using 8-inch outside diameter hollow -
stem augers, powered by a Mobile B61 HDX truck -mounted drilling rig with an auto -hammer.
The boring locations are shown on the :Boring and Infiltration Test Location Map, Figure 2, in
Appendix A. The locations shown are approximate, established by a hand-held GPS receiver
combined with .pacing and sighting from existing topographic features. GPS-derived horizontal
locations are accurate to within about 10 to 15 feet.
Samples were obtained within the test borings using a Standard. Penetration [SPT] sampler
(ASTM D 1586) and a Modified California [M.C] ring sampler (ASTM D 3550 with shoe similar
to ASTM D 1586). The SPT sampler has a 2-inch outside diameter and a 1.38-inch inside
diameter. The MC sampler has a 3-inch outside diameter and a 2.37-inch inside diameter. The
samples were obtained by driving the sampler with a 140-pound automatic hammer, dropping
30 inches in general accordance with ASTM D 1586. Recovered soil samples were sealed in
containers and returned to the laboratory. Bulk samples were also obtained from auger cuttings,
representing a mixture of soils encountered at the depths noted.
The final logs of the borings represent our interpretation of the contents of the field logs and'the
results of laboratory testing performed on the samples obtained during the subsurface
exploration. The final logs "are included in Appendix A of this report. The stratification lines
represent the approximate boundaries between soil types, although the transitions may be
gradational. ,
2.2 Laboratory Testing
Samples were reviewed along with field logs to select those that would be analyzed further.
Those selected for laboratory testing- include soils that would be exposed and used during
grading and those deemed to be within the influence of the proposed structure. Test results are
presented in graphic and tabular form in Appendix B of this report. The tests were conducted in
general accordance with the procedures of the American Society for Testing and Materials
[ASTM] or other standardized methods as referenced below. Our testing program consisted of
the following:
➢ In -situ Moisture Content and Unit Dry Weight for the ring samples.
➢ Maximum density tests to evaluate the moisture -density relationship of typical soils
encountered.
➢ Particle Size Analysis to classify and evaluate soil composition.' The gradation
characteristics of selected samples were made by hydrometer and sieve analysis
procedures.
EARTH SYSTEMS SOUTHWEST
December 30, 2008 5 File No.: 07711-31
Doc. No.: 08-12-769
➢ Consolidation (Collapse Potential) to evaluate the compressibility and
hydroconsolidation (collapse) potential of the soil.
➢ Chemical Analyses (Soluble Sulfates and Chlorides, pH, and Electrical Resistivity) to
evaluate the potential adverse effects of the soil on concrete and steel.
2.3 Infiltration Testing
The purpose of the infiltration testing was to measure the ultimate infiltration rate to be used
with an appropriate factor of safety in designing the onsite storm water disposal facilities. The
infiltration test borings were located in the general vicinity of two proposed storm water
retention basins, to be located near the center of the parcel, and at the northeast corner. The
approximate test locations are shown on Figure 2 in Appendix A.
To aid .in designing the northeast retention basin; we conducted an open, double ring
infiltrometer test on November 21, 2008, in general accordance with ASTM D3385, at the
proposed basin location. The test was conducted at the bottom of the existing drainage swale, at
the approximate proposed bottom. elevation of the 'basin.. An outer steel ring (24-inch diameter)
and an inner steel ring (12-inch diameter) were driven about 5.5 to 6 inches into the soil. The
purpose of the outer ring is to create a hydraulic barrier so that the recorded drop in water level
of the inner ring measures the vertical infiltration without lateral spreading. Both rings were
filled with water to a depth of about 4 inches and maintained. Successive readings of infiltration
flow were made over 15-, 30-, and 60-minute periods until a stabilized flow was recorded. A
plot of infiltration rates over time is presented on the attached test results.
The ultimate infiltration rate measured is presented in the following in metric and equivalent
English units.
Test Location
Depth
(feet)
cm/hr
in/hr
galIsf/day
I-1
2
1.8
0.7
10
Two falling head percolation tests; one at each proposed retention basin, were performed within
exploratory Borings B-2 and B-4, drilled to depths of approximately 60 feet below the existing
ground surface. The tests were conducted to aid in the design of a MaxWell Plus, or equivalent
dry well system. A 3/4-inch diameter perforated pipe with sock was set in the boreholes and the
annulus was backfilled with'/4-inch sized gravel for Boring B-2. Soils within Boring B-4 caved
around the PVC pipe preventing backfil.ling of the annulus with gravel. The percolation testing
was accomplished on November 20 and 21, .2008. The tests were made in conformance to the
Riverside County percolation test method, as described in "Waste Disposal for Individual
Homes, Commercial and Industrial," published by the Riverside County Division of
Environmental Health (RCDEHJ. The boreholes were filled with water and presoaked.
Successive readings of drop in water level were made over several, 2- to 30-minute periods until
a stabilized drop was recorded. The field percolation test results are presented in the following
table:
EARTH SYSTEMS SOUTHWEST
December 30, 2008 6 File No.: 07711-31
Doc. No.: 08-12-769
Bottom of
Hydraulic Conductivity (k)
Hole
Test ID
feet
Inin/hr ft/da
B-2
60
0.00108
0.78
.1.6
B-4
60
..00056
0.40
0.8
To aid in designing the central retention basin, one shallow pump -in (constant head) infiltration
test was conducted within Boring B-5 in the vicinity of the proposed basin, as shown on Figure
2. The test was conducted within the 8-inch diameter, augered borehole made to a depth of 20
feet below existing ground surface. A 3'/4-inch diameter perforated pipe with sock was set in the
borehole and backf lled with gravel around the pipe. Water was injected at a relatively constant
rate until a stabilized head of water was established. The testing was completed on November
20, 2008 according to the guidelines of the U.S. Bureau of Reclamation Method for Unsaturated
Soils above Groundwater. The ultimate test results are presented in the table below:
Test
ID
Bottom of Hole
feet
Water Head
feet
Flow Rate
m
Hydraulic Conductivity
in/hr aUsf/da
B-5
20
3.32
0.36
0.99
14.8
Estimated Hydraulic Conductivity
In addition to the field infiltration- testing, sieve analyses performed on select boring samples
were used to estimate the hydraulic conductivity, of the soils near Borings B-2 and B-4. The
diameter of the finest 10 percent size -fraction of the soil (referred to as the D10) was used in the
Hazen formula to estimate the conductivity of the soils for which the sieve analyses were
performed. Multiple samples were tested from each soil horizon, and conductivities derived
from these sieve analyses that were deemed to be representative of the sand layers in the overall
soil horizon were used as the basis for the infiltration rate evaluation.
Drywell depths were identified that would best fit the soil stratigraphy encountered in the
borings. Hypothetical -water infiltration capacities were estimated using the identified drywell
designs. Note that conductivity rates are highly variable between soils types; highly conductive
layers can transmit orders -of -magnitude more water than low conductivity layers. Therefore, the
availability of high -conductivity layers is the "rate limiting step" from a water disposal
perspective. The distribution and thickness of the more -conductive soil layers and their position
in the soil column were used to evaluate the water -disposal characteristics in each area. This
was performed by characterizing the soil column at each boring location as generally fitting one
of three water disposal models: (A) uniform soils; (B) soils with an underlying boundary
condition; and (C) a pervious soil horizon with an overlying and underlying boundary condition.
The appropriate model was used to estimate the water disposal capacity of the soil at each
location using the conductivity and soil stratigraphy derived during this investigation. In
addition, the percent of impermeable soil in each soil horizon was estimated to model the
presence of interbedded silt and clay layers, and was used to decrease the effective thickness of
the receiving soil horizons.
EARTH SYSTEMS SOUTHWEST
December 30, 2008 7 File No.: 07711-31
Doc. No.: 08-12-769
Results of this analysis are included in Appendix A as Table 2; drywell-design recommendations
are included in Table 3.
Design Infiltration Rate
The designer of the storm water management systemsshould decide on an appropriate factor of
safety to apply to reported infiltration rate. Infiltration of storm water through drywells and the
bottom of the basin may be significantly less than the value given over time because of siltation
and development of films from road oils from paved streets. Maintenance of the storm -water
disposal facilities is crucial particularly if no factor of safety is applied. Maintenance may
include periodically scarifying the bottom of the basin to open soil pores clogged by siltation,
oils, or vegetation growth. A silt and oil trap placed at influent points may be considered to
reduce the potential for reduction in the infiltration rate of soils.
December.30, 2008 8 File No.: 07711.-31
Doc. No.: 08-12-769
Section 3
DISCUSSION
3.1 Soil Conditions
The .field exploration indicates that site soils in the upper 10 feet consist generally of medium
dense well graded sand with gravel and trace cobbles to medium dense to dense sand with silt
(Unified Soils Classification System symbols of SW-SM, SW, SP, and SP-SM). The upper 1.0
feet of soil were most likely deposited in an alluvial fan environment. Below 10 feet the soils
consist generally of medium dense sand with silt, silty sand, sandy silt and silt (SP-SM, SM, and
ML), probably deposited in the lacustrine environment of ancient Lake Cahuilla.
The boring logs provided in Appendix A include more detailed descriptions of the soils
encountered. The soils are visually classified to be in the very low expansion (E.I < 20) category.
Site soils are classified as Type C in accordance with CaIOSHA. Borehole elevations noted on
the boring logs are feet above mean sea level (NAVD29). Elevations were derived from the
Revised Rough Grading and Wall Plans provided by MSA Consulting, Inc. Please note that on
the rough grading plans, elevations are feet above mean sea level (NAVD29) plus 500 feet.
In arid climatic regions, granular soils may have a potential to collapse upon wetting. Collapse
(hydroconsolidation) may occur when the soluble cements (carbonates) in the soil matrix
dissolve, causing the soil to densify from its loose configuration from deposition. A dry silt
layer was observed .in Borings 2 through 5 at a depth of approximately 17 to 30 feet below
existing grade. This layer deepens to the west and may thin toward the west. It may be as much
as 5 feet. thick. One of the consolidation tests performed on this silt layer indicates a
3.6% collapse upon inundation and collapse is therefore considered a moderate to severe site
risk. Given the depositional environment of this silt layer, it is assumed to be present under at
least the east half of the project site, and probably under the entire site in varying thicknesses.
3.2 Groundwater
Free groundwater was not encountered in the borings' during exploration. The depth to
groundwater in the area is believed to be more than 100 feet using data from borings drilled by
ESSW at a site located approximateiy 0.75 miles east-southeast of the subject site; the depth to
groundwater at that site was measured to be about 40 feet below the ground surface. The
Travertine Parcel, which is farther up the alluvial fan, is approximately 100 feet higher in
elevation. Therefore, even though the water table slightly rises beneath the alluvial fan surface,
it does not rise at the same rate as the ground surface, and is most likely deeper than 100 feet.
However, there is uncertainty in the accuracy of short-term water level measurements.
Groundwater levels may fluctuate with precipitation, irrigation, drainage, regional pumping from
wells, and site grading. The absence of groundwater levels detected may not represent an
accurate or permanent condition. Groundwater should not be a factor in design or constriction
at this site.
3.3 Geologic Setting
Regional. Geology: The site lies within the Coachella Valley, a part of the Colorado Desert
geomorphic province. A significant feature within the Colorado Desert geomorphic province is
EARTH SYSTEMS SOUTHWEST
December 30, 2008 9 File No.: 07711-31
Doc. No.: 08-12-769
the Salton Trough. The Salton Trough is a large northwest -trending structural depression that
extends approximately 180 miles from the San Gorgonio Pass to the Gulf of California. Much of
this depression in the area of the Salton Sea is below sea level.
The Coachella Valley forms the northerly part of the Salton Trough. The Coachella Valley
contains a thick sequence of Miocene to Holocene sedimentary deposits. Mountains- surrounding
the Coachella Valley include the Little San Bernardino .Mountains on the northeast, foothills of
the San .Bernardino Mountains on the northwest, and the San Jacinto and Santa Rosa Mountains
on the southwest. These mountains expose primarily Precambrian metamorphic and Mesozoic
granitic rocks. The San Andreas fault zone within the Coachella Valley consists of the Garnet
Hill fault, the Banning fault, and the Mission Creek fault that traverse along the northeast margin
of the valley.
Local Geology: The project site is located approximately 15 to 30 feet below mean sea level in
the southwestern part of the Coachella Valley. The sediments within the valley consist of fine -
to coarse -grained sands with interbedded clays, silts, gravels, and cobbles of aeolian (wind-
blown), lacustrine (lake -bed), and alluvial (water -laid) origin.
3.4 Geologic Hazards
Geologic hazards that may affect the region include seismic hazards (ground shaking, surface
fault rupture, soil liquefaction, and other secondary earthquake -related hazards), flooding,
ground subsidence, and erosion. A discussion follows on the specific hazards to this site.
3.4.1 Seismic Hazards
Seismic Sources: Several active faults or seismic zones lie within 62 miles (100 kilometers) of
the project site as shown on Table 1. in Appendix A. The primary seismic hazard to the site is
strong ground shaking from earthquakes along the San Andreas and San Jacinto faults. The
Maximum Magnitude Earthquake (Mma.,) listed is from published geologic information available
for each fault (Cao et al., CGS,.2003). The Mmax corresponds to the maximum earthquake
believed to be tectonically possible.
Surface Fault .Rupture: The project site does not lie within a currently delineated State of.
California, Alquist-Priolo Earthquake Fault Zone (Hart, 1997). Well -delineated fault lines cross
through this region as shown on California Geological Survey [CGS] maps (Jennings, 1994);
however, no active faults are mapped in the immediate vicinity of the site. Therefore, active
fault rupture is unlikely to occur at the project site. While fault rupture would most likely occur
along previously established fault traces, future fault rupture could occur at other locations.
Historic Seismicity: Six historic seismic events (5.9 M or greater) have significantly affected the
Coachella Valley in the last 1.00 years. They are as follows:
• Desert Hot Springs Earthquake — On December 4, 1948, a magnitude 6.5 ML (6.OMW)
earthquake occurred east of Desert Hot Springs. This event was strongly felt in the La
Quinta area.
• Palm Springs Earthquake — A magnitude 5.9 ML (6.2MW) earthquake occurred on July 8,
1986 in the Painted Hills, causing minor surface creep of the Banning segment of the San
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Andreas fault. This event was strongly felt in the La Quinta area and caused structural
damage, as well as injuries.
Joshua Tree Earthquake — On April 22, 1992, a magnitude 6.1.ML (6.lMW) earthquake
occurred in the mountains 9 miles east of Desert Hot Springs. Structural damage and minor
injuries occurred in the La Quinta area as a result of this earthquake.
Landers and Big Bear Earthquakes — Early on June 28, 1992, a magnitude 7.5 Ms (7.3MW)
earthquake occurred near Landers, the largest seismic event in Southern California for
40 years. Surface rupture occurred just south of the town of. Yucca Valley and extended
some 43 miles toward Barstow. About three hours later, a magnitude 6.6 Ms (6.4MW)
earthquake occurred near Big Bear .Lake. No significant structural damage from these
earthquakes was reported in the La Quints area.
Hector Mine Earthquake — On October 16, 1999, a magnitude 7.1.MW earthquake occurred
on the Lavic Lake and Bullion Mountain faults north of Twentynine Palms. While this event
was widely felt, no significant structural damage has been reported in the Coachella Valley.
Seismic Risk: While accurate earthquake predictions are not possible, various agencies have
conducted statistical risk analyses. In 2002 and 2008, the California Geological Survey [CGS]
and the United States Geological Survey [USGS] completed of probabilistic seismic hazard
maps. We have used these maps in our evaluation of the seismic risk at the site. The recent
Working Group of California Earthquake Probabilities (WGCEP, 2008) estimated a 58%
conditional probability that a magnitude 6.7 or greater earthquake may occur between 2008 and
2038 along the southern segment of the San Andreas fault.
The primary seismic risk at the site is a potential earthquake along the Southern San Andreas
fault, located about 14.7 km (9.1 miles) from the site and is considered as fault type A (CGS).
Geologists believe that the San Andreas fault has characteristic earthquakes that result from
rupture of each fault segment. The estimated characteristic earthquake is magnitude 7.7 for the
Southern Segment of the fault (USGS, 2002). This segment has the longest elapsed time since
rupture of any part of the San Andreas fault. The last rupture occurred about 1680 AD, based on
dating by the USGS near Indio (WGCEP, 2008). This segment has also ruptured on about 1020,
1300, and 1450 AD, with an average recurrence interval of about 220 years. The San Andreas
fault may rupture in multiple segments, producing a higher magnitude .earthquake. Recent
paleoseismic studies suggest that the San Bernardino Mountain Segment to the north and the
Coachella Segment may have ruptured together in 1450 and 1690 AD (WGCEP, 1.995).
3.4.2 Secondary Hazards
Secondary seismic hazards related to ground shaking include soil liquefaction, ground
subsidence, tsunamis, and seiches. The site is far inland, so the hazard from tsunamis is non-
existent. At the present time, no water storage reservoirs are located in the immediate vicinity of
the site. Therefore, hazards from seiches are considered negligible at this time.
Soil Liquefaction: Liquefaction is the loss of soil strength from sudden shock (usually
earthquake shaking), causing the soil to become a fluid mass. In general, for the effects of
liquefaction to be manifested at the surface, groundwater levels must be within 50 feet of the
ground surface and the soils within the saturated zone must also be susceptible to liquefaction.
The potential for liquefaction to occur at this site is considered negligible because the depth of.
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groundwater beneath the site exceeds 50 feet. No free groundwater was encountered in our
exploratory borings. In addition, the project lies in a zone designated by Riverside County for
high susceptibility sediments, but deep groundwater resulting in low liquefaction potential.
Ground Subsidence: The potential for seismically induced ground subsidence is considered to
be low at the site. Dry sands tend to settle and densify when subjected to strong earthquake
shaking. The amount of subsidence is dependent on relative density of the soil, ground motion,
and earthquake duration. Uncompacted fill areas may be susceptible to seismically. induced
settlement.
Slope Instability: The site is relatively flat. Therefore, potential hazards from slope instability,
landslides, or debris flows are considered negligible.
Flooding: The project site does not lie within a designated FEMA 100-year flood plain, but is in
an area for which flood hazards are undetermined, but possible. The parcel is adjacent to the
Trilogy development, which is designated by FEMA as an area protected by levees from a 1%
annual chance flood. Given the USBOR levee located immediately to the west of the parcel, this
site will most likely be included with the rest of the Trilogy development flood hazard
designation. The project site may be in an area where sheet flooding and erosion could occur.
Appropriate design, construction, and maintenance by the project civil engineer can minimize
the site sheet flooding potential.
3.4.3 Site Acceleration and Seismic Coefficients
Site Acceleration: The potential intensity'of ground motion may be estimated by the horizontal
peak ground acceleration (PGA),' measured in "g" forces. Included in Table 1. are deterministic
estimates of site acceleration from possible earthquakes at nearby faults. Ground motions are
dependent primarily on the earthquake magnitude and distance to the seismogenic (rupture)
zone. Accelerations are also dependent upon attenuation by rock and soil deposits, direction of
rupture, and type of fault. For these reasons, ground motions may vary considerably in the same
general area. This variability can be expressed statistically by a standard deviation about a mean
relationship.
The PGA alone is an inconsistent scaling factor and is generally a poor indicator of potential
structural damage during an earthquake. ' Important factors influencing the structural
performance are the duration. and frequency of strong ground motion, .local subsurface
conditions, soil -structure interaction, and structural details.
The following table provides the probabilistic estimate of the PGA taken from the
2002 CGS/USGS seismic hazard maps/data.
Estimate of PGA from 2002 CGS/USGS
Probabilistic Seismic Hazard Man -./Data
Risk
Equivalent Return
Period ears
PGA ( t
10% exceedance in 50 years
475
z0.46
Notes:
I Based on Site Class B/C and soil amplification factor of 1.0 for Site Class D.
2007 CBC Seismic 'Coefficients: The California Building Code [CBC] seismic design
parameters criteria are based on a Design Earthquake that has an earthquake ground motion. 2/3 of
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the lesser of 2% probability of occurrence in.50 years or 150% of mean deterministic limit. The
PGA estimate given above is provided for information on the seismic risk inherent in the CBC
design. The seismic and site coefficients given in Chapter 1.6 of the 2007 California Building
Code are provided in Section 5,8 of this report.
Seismic Hazard Zones: The site lies in a low liquefaction potential zone designated by the
2003 Riverside County Integrated Project because of deep groundwater (>50-.100 feet), and high
susceptibility sediments. This portion of Riverside County has not been mapped by the
California Seismic Hazard Mapping Act (Ca. PRC 2690 to 2699).
December 30, 2008 13
Section 4
CONCLUSIONS
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The following is a summary of our conclusions and professional opinions based on the data
obtained from a review of selected technical literature and the site evaluation.
General:
➢ From a geotechnical perspective, the site is suitable for the proposed development,
provided'the recommendations in this report are followed in the design and construction
of this project.
Geotechnical Constraints and Miti ation
➢ The primary geologic hazard is severe ground. shaking from earthquakes originating on
nearby faults. A major earthquake above magnitude 7 originating on the local segment of
the, San Andreas fault zone .would be the critical seismic event that may affect the site
within the design life of the proposed development. Engineered design and earthquake -
resistant construction increase safety and allow development of seismic areas.
➢ The underlying geologic condition for seismic design is Site Class D. The site is about
1.4.7 km from'a Type A seismic source as defined in the California Geological Survey. A
qualified professional should design any permanent structure constructed on the site. The
minimum seismic design should comply with the 2007 edition of the California Building
Code.
➢ Ground subsidence from seismic events or hydroconsolidation is a potential hazard in the
Coachella Valley area. Adherence to the grading and structural recommendations in this
report should reduce potential settlement problems from seismic forces, heavy rainfall or
irrigation, flooding, and the weight of the intended structures'.
➢ The soils are susceptible to wind and water erosion.. Preventative measures to reduce
seasonal flooding and erosion should be incorporated into site grading plans. Dust
control should also be implemented during construction. Site grading should be in strict
compliance with the requirements of the -South Coast Air Quality Management District
[SCAQMD].
➢ Other - geologic hazards, including fault rupture, liquefaction, seismically induced
flooding, and landslides, are considered low or negligible on this site..
➢ The upper soils were found to be non -uniform, relatively medium dense to very dense
and are unsuitable in their present condition to support. structures, fill, and hardscape.
The soils within the .proposed building and structural areas will require moisture
conditioning and compaction to improve bearing capacity and reduce the potential for
differential settlement from static loading. Due to the presence of a collapsible dry -silt
layer beneath the site, special foundation recommendations are provided for lots located
in the easternhalf of the parcel. Soils can be readily cut by normal grading equipment.
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Section 5
RECOMMENDATIONS
SITE DEVELOPMENT AND GRADING
5.1 Site Development — Grading
A representative of Earth Systems Southwest [ESSW] should observe site clearing, grading, and
the bottoms of excavations before placing fill. Local variations in soil conditions may warrant
increasing the depth of recompaction and over -excavation.
Clearing and Grubbing: At the start of site grading, existing vegetation, trees, large roots,
pavements, foundations, non -engineered fill, construction debris, trash, and abandoned
underground utilities should be removed from the proposed building, structural, and pavement
areas. The surface should be stripped of organic growth and removed from the construction area.
Areas disturbed during clearing should be properly backf Iled and compacted as described
below.
Dust control should also be implemented during construction. Site grading should be in strict
compliance with the requirements of the South Coast Air Quality Management District
(SCAQM.D).
Building Pad Preparation: In order to lower the overall site elevation, approximately 6 to 9 feet
of native soil will be excavated and exported to the adjacent Tract 30023-6, Phase 6B and 6C.
This will effectively lower the overall site elevation from approximately -1.2 feet to -20 feet.
Due to the relatively non -uniform and under -compacted nature of the site soils, we recommend
recompaction of soils in the building areas. The proposed -surface soils within the building pad
and foundation areas should be scarified, moisture conditioned, and compacted to at Least 90%
relative compaction (ASTM D 1557) to a minimum of 2 feet below proposed grade or a
minimum of 1. foot below.the footing level (whichever is lower). The compaction should extend
for 5 feet beyond the outer edge of exterior footings, where possible. Moisture. penetration to
near optimum moisture should extend at least one foot below existing grade. Compaction should
be verified by testing.
Auxiliary Structures Subgrade. Preparation: Auxiliary structures such as garden or retaining
walls should have the foundation subgrade prepared similar to the building pad
recommendations given above. The lateral extent of the over -excavation needs to extend only 2
feet beyond the face of the footing.
Subgrade Preparation: , In areas to receive fill, pavements, or hardscape, the subgrade should be
scarified, moisture conditioned, and compacted to at least 90% relative compaction
(ASTM D 1557) for a depth of one -foot below finished subgrades or one foot below the bottom
of the foundation, whichever is deeper. Compaction should be verified by testing.
Engineered Fill Soils: The native soil is suitable for use as engineered fill and utility trench
backfill, provided it is free of significant organic or deleterious matter. The native soil should be
placed in maximum 8-inch lifts (loose) and compacted to at least 90% relative compaction
(ASTM. D 1557) near its optimum moisture content. Compaction should be verified by testing.
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Rocks larger than 6 inches in greatest dimension should be removed from fill. or backf ll
material.
Imported fill soils (if needed) should be non -expansive, granular soils meeting the
USCS classifications of SM, SP-SM, or SW-SM. with a maximum rock size of 3 inches and
5 to 35% passing the No. 200 sieve. The geotechnical engineer should evaluate the import fill
soils before hauling to the site. .However, because of the potential variations within the borrow
source, import soil will not be prequalified by ESSW. The imported fill should be placed in lifts
no greater than 8 inches in loose thickness and compacted to at least 90% relative compaction
(AST.M D 1557) near optimum moisture content.
Shrinkage: The shrinkage factor for earthwork is expected to be less than 10 percent for the
upper excavated or scarified site soils. This estimate is based on compactive effort to achieve an
average relative compaction of about 92% and may vary with contractor methods. Subsidence is
estimated to be less than 0.1 feet. Losses from site clearing and removal of existing site
improvements may affect earthwork quantity calculations and should be considered.
Site Drainage: Positive drainage should be maintained away from the structures (5% for 5 feet
minimum) to prevent ponding and subsequent saturation of the foundation soils. Gutters and
downspouts should be considered as a means to convey water away from foundations if adequate
drainage is not provided. Drainage should be maintained for paved areas. Water should not
pond on or near paved areas.
5.2 Excavations and Utility Trenches
Excavations should be made in accordance with CalOSHA requirements. Using the Cal/OSHA
standards and general soil information obtained from. the field exploration, classification of the
near surface on -site soils will likely be characterized as Type C. Actual classification of site
specific soil type per Cal/OSHA specifications as they pertain to trench safety should be based
on real-time observations and determinations of exposed soils by the Competent Person during
grading and trenching operations. .
Our site exploration and. knowledge of the general area indicates there is a potential for caving of
site excavations (utilities, footings, etc.). Excavations within sandy soil should be kept moist,
but not saturated, to reduce the potential of caving or sloughing. Where excavations over 4 feet
deep are planned, lateral bracing or appropriate cut slopes of 1.5:1. (horizontal:vertical) should be
provided. No surcharge loads from stockpiled soils or construction materials should be allowed
within a horizontal distance measured from the top of the excavation slope and equal to the depth
of the excavation.
Utility Trenches: Backfill of utilities within roads or public right-of-ways should be placed in
conformance with the requirements of the governing agency (water district, public works
department, etc.). Utility trench backfill within private property should be placed in
conformance with the provisions of this report. In general, service lines extending inside of
property may be backfilled with native soils compacted to a minimum of 90% relative
compaction. Backfill operations should be observed and tested to monitor compliance with these
recommendations.
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5.3 Slope Stability of Graded Slopes
Unprotected, permanent graded slopes shouldnot be steeper than 3:1. (horizontal:vertical) .to
reduce wind and rain erosion. IProtected slopes with ground cover may be as steep as 2:1.
However, maintenance with motorized equipment may not be possible at this inclination. Fill
slopes should be overfilled and trimmed back to competent material. Slope stability calculations
are not presented because of the expected minimal slope heights (less than 5 feet).
STRUCTURES
In our professional opinion, structure foundations can be supported on shallow foundations
bearing. on a -zone of properly prepared and compacted soils placed 'as recommended in
Section 5.1. The recommendations that follow are based on very low expansion category soils..
5.4 Foundations
To accommodate potential settlement due to hydrocollapse of the silt layer, separate
recommendations are provided for the west and east halves of the project site. We recommend
additional drilling to further constrain the areal extentof the silt layer. This may result in a
decrease in the number of adversely impacted building pads.
Footing design of widths, depths,and reinforcing are the, responsibility of the Structural
Engineer, considering the structural loading and .the geotechnical parameters given in this report.
A minimum footing depth of 12 inches below lowest adjacent grade should be maintained for
building pads located in the west half of the project site. For pads located in the east half. a
minimum footing depth of 15 inches below lowest ad'a1 cent grade should be maintained A
representative of ESSW should observe,foundation excavations before placement of reinforcing
steel or concrete. Loose soil or construction debris should be removed from footing excavations
before placement of concrete.
Conventional Spread Foundations: Allowable soil bearing pressures are given below for
foundations bearing on recompacted soils as described in Section 5.1. Allowable bearing
pressures are net (weight of footing and soil surcharge may be neglected).
Continuous wall foundations, 12-inch minimum width and 12 inches below lowest adjacent
grade for building pads located in the west half of the project site, 15 inches below lowest
adjacent grade for the east half:
1500 psf for dead plus design live loads
Allowable increases of 200 psf per each foot of additional footing width and 300 psf for each
additional 0.5 foot of footing depth may be used up to a maximum value of 2500 psf.
Isolated pad foundations, 2 x 2 foot minimum in plan and 18 inches below grade:
2000 psf for dead plus design live loads
Allowable increases of 300 psf per each foorof additional footing width and 400 psf for each
additional 0.5 foot of footing depth may be used up to a maximum value of 2500 psf.
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A one-third ('/3) increase in the bearing pressure may be used when calculating resistance to wind
or seismic loads. The allowable bearing values indicated are based on the anticipated maximum
loads stated in Section L 1. of this report. If the anticipated loads exceed these values, the
geotechnical engineer must reevaluate the allowable bearing values and the grading
requirements.
Minimum reinforcement for continuous wall footings for building pads located in the west half
of the project site should be two No. 4 steel reinforcing bars, one placed near the top and one
placed near the bottom of the footing. Minimum reinforcement for continuous wall footings for
pads in the east halfshould be four No. S steel reinforcing bars two placed near the top and two
placed near the bottom of the footing. This reinforcing is not intended to supersede any
structural requirements provided by the structural engineer.
Expected Settlement: Estimated total static settlement should be less than one -inch, based on
footings founded on firm soils as recommended. Differential settlement between exterior and
interior bearing members should be less than %2-inch, expressed in a post -construction angular
distortion ratio of 1:480 or less.
Settlement induced from hydrocollapse, based on a 5-foot thick silt layer and 3.6% settlement at
2.0 ksf, may be up to approximately 2.2 inches with surface reaction estimated to be about one-
half this value. Utility connections to structures should be flexible and able to accommodate this
potential movement.
Frictional and Lateral Coefficients: Lateral loads may be resisted by soil friction on the base of
foundations and by passive resistance of the soils acting on foundation walls. An allowable
coefficient of friction of 0.35 of dead load may be used. An allowable passive equivalent fluid
pressure of 350 pcf may also be used. These values include a factor of safety of 1.5. Passive
resistance and frictional resistance may be used in combination if the friction coefficient is
reduced by one-third. A one-third ('/3) increase in the passive pressure may be used when
calculating resistance to wind or seismic loads. Lateral passive resistance is based on the
assumption that backfill next to foundations is properly compacted.
5.5 Slabs -on -Grade
Subgrade: Concrete slabs -on -grade and flatwork should be supported by compacted soil placed
in accordance with Section 5.1 of this report.
Vapor Retarder: In areas of moisture sensitive floor coverings, an appropriate vapor retarder
should be installed to reduce moisture transmission from the subgrade soil to the slab. For these
areas, an impermeable membrane (1.0-mil thickness) should underlie the floor slabs. The -
membrane should be covered with 2 inches of sand to help protect it during construction and to
aid in concrete curing. The sand should be lightly moistened just prior to placing the concrete.
Low -slump concrete should be used to help reduce the potential for concrete shrinkage. The
effectiveness of the membrane is dependent upon its quality, the method of overlapping, its
protection during construction, and the successful sealing of the membrane around utility lines.
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The following minimum slab recommendations are intended to address geotechnical concerns
such as potential variations of the subgrade and are not to be construed as superseding any
structural design. The design engineer -and/or project architect should ensure compliance
with SB800 with regards to moisture and moisture vapor.
Slab Thickness and Reinforcement: Slab thickness and reinforcement of slabs -on -grade are
contingent on the recommendations of the structural engineer or architect and ,the expansion
index of the supporting soil. Based upon our findings, a modulus of subgrade reaction of
approximately 200 pounds per cubic inch can be used in concrete slab design for the expected
very low expansion subgrade.
Concrete slabs and flatwork should be a minimum of S inches thick (actual, not nominal). We
suggest that the concrete slabs be reinforced with a minimum of No. 3 rebars at 18-inch centers,
both horizontal directions, placed at slab mid -height to resist potential cracking. Concrete floor
slabs may either be monolithically placed with the foundations or doweled after footing
placement. The thickness and reinforcing given are not intended to supersede any structural
requirements provided by the structural engineer. The project architect or geotechnical engineer
should continually observe all reinforcing steel. in slabs during placement of concrete to check
for proper location within the slab.
Control Joints: Control joints should'be provided in all concrete slabs -on -grade at a maximum
spacing of 36 times the slab thickness (12 feet maximum. on -center, each way) as recommended
by American Concrete Institute [ACI] guidelines. Alt joints should form approximately square
patterns to reduce the potential for randomly oriented shrinkage cracks. Construction joints in
the slabs should be tooled at the time of the concrete placement or saw cut ('/4 of slab depth) as
soon as practical but not more than 8 hours from concrete placement. Construction (cold) joints
should consist of thickened butt joints with '/2-inch dowels at 18-inches on center or a thickened
keyed joint to resist vertical deflection at the joint. All construction joints in exterior flatwork
should be sealed to reduce the potential of moisture or foreign material intrusion. These
procedures will reduce the potential for randomly oriented cracks, but may not prevent them
from occurring.
Curing and Quality Control: The contractor should take precautions to reduce the potential of
curling of slabs in this and desert region using proper batching, placement, and curing methods.
Curing is highly affected by temperature, wind, and humidity. Quality control procedures may
be used, including trial batch mix designs, batch plant inspection, and on -site special inspection
and testing. Typically, for this type of construction and using 2500-psi concrete, many of these
quality control procedures are not required.
5.6 Retaining Walls
The following table presents lateral earth pressures for use in retaining wall design. The values
are given as equivalent fluid pressures without surcharge loads or hydrostatic pressure.
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Lateral Pressures and Sliding Resistance i
Granular Backfill
Passive Pressure
350 pcf - level ground
Active Pressure (cantilever walls)
Use when wall is permitted to rotate 0.1 to 0.2% of wall
35 pcf - level ground
height for granular backfill
At -Rest Pressure restrained walls
55 pcf - level ground
Dynamic Lateral Earth Pressure Z
Acting at 0.6H,
15 pcf
Where H is height of backfill in feet
Base Lateral Sliding Resistance
0.50
Dead load x. Coefficient of Friction:
Notes:
I These values are ultimate values. A factor of safety of 1.5 should be used in stability analysis
except for dynamic earth pressure where a factor of safety of 1.2 is acceptable.
2 Dynamic pressures are based on the Mononobe-Okabe 1929 method, additive to active earth
pressure. Walls retaining less than 6 feet of soil and not supporting inhabitable structures need
not consider this increased pressure (reference: CBC Section 1630A. 1. 1.5).
Upward sloping backfill or surcharge loads from nearby footings can create larger lateral
pressures. Should any walls be considered for retaining sloped backfill or placed next to
foundations, our office should be contacted for recommended design parameters. Surcharge
loads should be considered if they exist within a zone between the face of the wall and a plane
projected 45 degrees upward from the base of the wall. The increase in lateral earth pressure
should be taken as 35% of the surcharge load within this zone. Retaining walls subjected to
traffic loads should include a uniform surcharge load equivalent to at least 2 feet of native soil.
Drainage: A backdrain or an equivalent system of backfill drainage should be incorporated into
the retaining wall design, whereby, the collected water is conveyed to an approved point of
discharge. Our firm can provide construction details when the specific application is
determined. Backfill immediately behind the retaining structure should be a free -draining
granular material. Waterproofing should be according to the designer's specifications. Water
should not be allowed to pond near the top of the wall. -To accomplish this, the final backfill
grade should be such that all water is diverted away from the retaining wall.
Backfill and Subgrade Compaction: Compaction on the retained side of the wall within a
horizontal distance equal to one wall height should be performed by hand -operated or other
lightweight compaction equipment. This is intended to reduce potential locked -in lateral
pressures caused by compaction with heavy grading equipment. Foundation subgrade
preparation should be as specified in Section 5.1.
5.7 Mitigation of Soil Corrosivity on Concrete
Selected chemical analyses for corrosivity were conducted on soil samples from the project site
as shown in Appendix B.
Sulfate and other salts can attack the cement within concrete causing weakening of the cement
matrix and eventual deterioration by raveling. This attack can be in the form of a physical attack
or chemical attack whereby there may be a chemical reaction between the sulfate and the cement
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used in the concrete. According to ACI 318 as referenced by the 2007 California Building Code,
if sulfate concentrations exceed 1.000 ppm there will be special requirements. For this project,
the results of those samples tested suggesta low sulfate ion concentration (78-20 ppm). Normal
concrete mixes may be used.
Electrical resistivity is a process whereby metal (ferrous) objects in direct contact with soil may.
be subject to attack by electrochemical corrosion. This typically pertains to buried metal pipes,
valves, culverts, etc. made of ferrous metal. To avoid this type of corrosion or to slow the
process, buried metal objects are generally protected with waterproof resistant barriers, i.e.
epoxy corrosion inhibitors, asphalt coatings, cathodic protection, or.encapsulating with densely
consolidated concrete. Electrical resistivity testing of the soil suggests that the site soils may
present a moderate to very severe potential for metal loss from electrochemical corrosion
.processes.
Chloride ions can cause corrosion of reinforcing steel. For this project, the results of those
samples tested suggest a low chloride ion concentration (28-51 ppm). ACI 318 is referenced by
the California Building Code, and provides commentary relative to the effects of chlorides
present in the soil; from both internal and external sources. It is possible that long term
saturation of foundations with chloride rich water could allow the. chloride access to the
reinforcing steel. The soils encountered on this site consist of relatively free draining material
over fairly fractured bedrock. Therefore, if the site is adequately.. drained in accordance with
sound engineering practice and the applicable codes, this should be a low threat.
A minimum concrete cover, of cast -in -place concrete should be in accordance with Section 7.7 of
the 2007 edition of ACI 318. Additionally, the concrete should be thoroughly vibrated during
placement.
The information provided above should be considered preliminary. These values can potentially .
change based on several factors, such as importing soil from another job site and the quality of
construction water used during grading and subsequent landscape irrigation.
Earth Systems does not practice corrosion engineering. We , recommend that a qualified
corrosion engineer evaluate the corrosion potential on metal construction materials and concrete
at the site to provide mitigation of corrosive effects, if further guidance is desired.
5.8 Seismic Design Criteria
This site is subject to strong ground shaking due to potential fault movements along the
San Andreas and San Jacinto faults. Engineered design and earthquake -resistant construction
increase safety and, allow development of seismic areas. The minimum seismic design should
comply with the 2007 edition of the California Building Code and ASCE 7-05 using the seismic
coefficients given in the table below.
EARTH SYSTEMS SOUTHWEST
December 30, 2008 21 File No.: 07711-3I
Doc. No.: 08-12-769
Seismic Category:
Site Class:
2007 CBC (ASCE 7-05) Seismic Parameters
91
Maximum Considered Earthquake [MCE] Ground Motion
Short Period Spectral Response SS:
1 second Spectral Response, Si:
Site Coefficient, Fa:.
Site Coefficient, F,,:
Design Earthquake Ground Motion
Short Period Spectral Response, SDs
1 second Spectral Response, SDI
Reference
Table 1613.5.6
Table 161.3.5.2
1.50 g Figure 1613.5
0.60 g Figure 1613.5
1.00 Table 1613.5.3(1)
1.50 Table 1613.5.3(2)
1.00 g
0.60 g
The intent of the CBC lateral force requirements is to provide 'a structural design that will resist
collapse to provide reasonable life safety from a major earthquake, but may experience some
structural and nonstructural damage. A fundamental tenet of seismic design is that inelastic
yielding is allowed to adapt to the seismic demand on the structure. In other words, damage is
allowed. The CBC lateral force requirements should be considered a minimum design. The
owner and the designer may evaluate the level of risk and performance that is acceptable.
Performance based criteria could be set. in the. design. The design. engineer should exercise
special care so that all components of the design are fully met with attention to providing a
continuous load path. An adequate quality assurance and control program is urged during
project construction to verify that the design plans and good construction practices are followed.
This is especially important for sites lying close to the major seismic sources. .
Estimated peak horizontal site accelerations based upon a probabilistic analysis (10% probability
of occurrence in 50 years) is approximately 0.46 g for a stiff soil site. Actual accelerations may
be more or less than estimated. Vertical accelerations are typically '/3 to % of the horizontal
accelerations, but can equal or exceed the. horizontal accelerations, depending upon the local site
effects and amplification.
5.9 Pavements
Since no traffic loading was provided by the design engineer or owner, we have assumed traffic
loading for comparative evaluation. The design engineer or owner should decide the appropriate
traffic conditions for the pavements. Maintenance of proper drainage is advised to prolong the
service life of the pavements. Water should not pond on or near paved areas. The following
table provides our preliminary recommendations for pavement sections. Final pavement sections
recommendations should be based on design traffic indices and R-value tests conducted during
grading after actual subgrade soils are exposed.
EARTH sYSTEMs SOUTHWEST
December 30, 2008 22 File No.: 07711.-31
Doc. No.: 08-12-769
PRELIMINARY RECOMMENDED PAVEMENTS SECTIONS
R-Value Suhgrade Soils - 50 (accnrneA) r)Pe;on MPthnri _ (`el TO AM4Z
Flexible Pavements
Rigid Pavements
Asphaltic
Aggregate
Portland
Aggregate
Traffic
Pavement Use
Concrete
Base
Cement
Base
Index
Thickness
Thickness
Concrete
Thickness
Assumed
Inches
Inches
Inches
Inches
5.0
Auto Parking Areas
3.0
4.0
4.0
4.0
6.0
Residential Streets
3.5
4.0
5.0
4.0
Notes:
1. Asphaltic concrete should be Caltrans, Type B, %2-in. or 3/4-in. maximum -medium grading and compacted to a
minimum of 95% of the 75-blow Marshall density (ASTM D 1.559) or equivalent.
2. Aggregate base should be Caltrans Class 2 (3/4 in. maximum) and compacted to a minimum of 95% of ASTM
131557 maximum dry density near its optimum moisture.
3. All pavements should be placed on 12 inches of moisture -conditioned subgrade, compacted to a minimum of 90%
of ASTM D 1557 maximum dry density near its optimum moisture.
4. Portland cement concrete should have a minimum of 3250 psi compressive strength at 28 days.
5. Equivalent Standard Specifications for Public Works Construction (Greenbook) maybe used instead of Caltrans '
specifications for asphaltic concrete and aggregate base.
December 30, 2008 23 File No.: 07711-31.
Doc. No.: 08-12-769
Section 6
LIMITATIONS AND ADDITIONAL SERVICES
6.1 Uniformity of Conditions and Limitations
Our findings and recommendations in this report are based, on selected points of field
exploration, laboratory testing, and our -understanding of the proposed project. Furthermore, our
findings and recommendations are based on the assumption that soil conditions do not vary
significantly from those found at specific exploratory locations. Variations in soil or
groundwater conditions could exist between and beyond the exploration points. The nature and
extent of these variations may not become evident until construction. Variations in soil or
groundwater may require additional studies, consultation, and possible revisions to our
recommendations.
Findings of this report are valid as of the issued date of the report. However, changes in
conditions of a property can occur with passage of time, whether they are from natural processes
or works of man., on this or adjoining properties. In addition, changes in applicable standards
occur, whether they result from legislation or 'broadening of knowledge. Accordingly, 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 one year.
In the event that any changes in the. nature, design, or location of structures are planned, the
conclusions and recommendations 'contained in this report shall not be considered valid unless
the changes are reviewed and the conclusions of this report are modified or verified in writing.
This report is issued with the understanding that the owner or the owner's representative has the
responsibility to bring the information and recommendations contained herein to the attention of
the architect and engineers for the project so that they are incorporated into the plans and
specifications for the project. The owner or the. owner's representative also has the
responsibility to verify that the general contractor and all subcontractors follow such
recommendations. It is further understood that the owner or the owner's representative. is
responsible for submittal of this report to the appropriate governing agencies.
As the Geotechnical Engineer of. Record for this project, Earth Systems Southwest [ESSW] has
striven to provide our services in accordance with generally accepted geotechnical engineering
practices in this locality at this time. No warranty or guarantee is express or implied. This
report was prepared for the exclusive use of the Client and the Client's authorized agents.
ESSW should be provided the opportunity for a general review of final design and specifications
in order that earthwork and foundation recommendations may be properly interpreted and
implemented in the design and specifications. If ESSW is not accorded the privilege of making
this recommended review, we can assume no responsibility for misinterpretation of our
recommendations.
EARTH SYSTEMS SOUTHWEST
December 30, 2008 24 File No.: 07711.-31
Doc. No.: 08-12-769
Although available through ESSW, the current scope of our services does not include an
environmental assessment 'or an investigation for the presence or absence of wetlands, hazardous
or toxic materials in the. soil, surface water_; groundwater, or air on, below, or adjacent to the
subject property.
6.2 Additional Services
This report is based on the. assumption that an adequate program of client consultation,
construction monitoring, -and testing will be performed during the`fnal design and construction
phases . to check compliance with these 'recommendations. Maintaining ESSW as the
geotechnical consultant from beginning to end of the project.will provide continuity of services.
The geotechnical engineering firm providing tests and observations shall assume the
responsibility of'Geotechnical Engineer of Record.
Construction monitoring and testing would be additional services provided by our firm. The
costs of these services are not included in our present fee arrangements, but can be obtained from
our office. The recommended review, tests, and observations include, but are not necessarily
limited to, the following:
• Consultation during the final design stages of the project.
• A review of the building and grading plans to observe that recommendations of our
report have been properly implemented into the design.
Observation and testing during site preparation, grading, and placement of engineered fill
as required by CBC Sections 170.4.7 and Appendix J or local grading ordinances.
e Consultation.as needed during construction:
-000-
Appendices as cited are attached and complete this report.
EARTH SYSTEMS SOUTHWEST
;A:
December 30, 2008 25 File No.: 07711-31
Doc. No.: 08-12-769
REFERENCES
Abrahamson, N., and Shedlock, K., editors, 1997, Ground motion attenuation relationships:
Seismological Research Letters, v. 68, no. 1, January 1997 special issue, 256 p.
American Concrete Institute [ACT], 2004, ACI Manual of Concrete Practice, Parts 1 through 5.
American Concrete Institute (2004) `Building Code Requirements for Structural Concrete (ACI
318-05) and Commentary (ACI 318R-05)."
American Society of Civil Engineers [ASCE], 2006, Minimum Design. Loads for Buildings and
Other Structures, ASCE 7-05.
California Department of Water'Resources, 1964, Coachella Valley Investigation, Bulletin No. 108,
1.46 pp.
California Geologic Survey (CGS), 1997, Guidelines for Evaluating and .Mitigating Seismic Hazards
in California; Special Publication:11.7..
Cao, T, Bryant, W.A., Rowhandel, B., Branum. D., and Wills, C., 2003, The Revised 2002
California Probabilistic Seismic,.Hazard Maps, California Geologic Survey [CGS], June
2003.
Frankel, A.D., et al., 2002, Documentation for the 2002 Update of the National Seismic Hazard
Maps, USGS Open -File Report 02420.
Hart, E.W., 1997, Fault:Rupture Hazard Zones in California: California Division of Mines and
Geology Special Publication 42.
International Code Council [TCC], 2007, California Building Code, 2007 .Edition.
Jennings, C.W, 1994;"Fault Activity Map of California and Adjacent Areas: California Division of
Mines and Geology, Geological Data Map No. 6, scale 1:750,000.
Petersen, M.D., Bryant, W.A., Cramer, C.H., Cao, T., .Reichle, M.S., Frankel, A.D., Leinkaemper,
J.J., McCrory, P.A., and Schwarz,.D.P., 1996,.Probabilistic Seismic Hazard Assessment for
the State of California: California Division of Mines and Geology Open -File Report 96-08.
Riverside County Planning Department, 2002, Geotechnical Element of the Riverside County
General Plan - Hearing Draft.
Rogers, T.H., 1966, Geologic Map of California - Santa Ana Sheet, California Division of Mines
and Geology Regional Map Series, scale 1:250,000.
Tokimatsu, K, and Seed, H.B., 1987, Evaluation of Settlements in Sands Due To Earthquake
Shaking, ASCE, Journal of Geotechnical Engineering, Vol. 113, No. 8, August 1987.
United States Department of Homeland Securities, FEMA Map Center, flood map number
06065C2925G, Riverside CO, dated August 28, 2008.
Wallace, R. E., 1990, The San Andreas Fault System, California: U.S. Geological Survey
Professional Paper 1515, 283 p.
Working Group on California Earthquake Probabilities, 1995, Seismic Hazards in Southern
California: Probable Earthquakes, 1994-2024: Bulletin of the Seismological Society of
America, Vol. 85, No.2, pp. 379-439.
EARTH SYSTEMS SOUTHWEST
APPENDIX A
Figure 1 — Site Location
Figure 2 —Boring and Infiltration Test Locations
Table I —Fault Parameters
Terms and Symbols used on Boring Logs
Soil Classification System
Logs of Borings
Infiltration Test Results
Table 2 — Initial Estimated Conductivities
Table 3 — Drywell. Design and Infiltration Model
EARTH SYSTEMS SOUTHWEST
11601522"1V 116014'22"IV
c 568000 568S00 569000 569500 570000 570500 571000 571500 po
o p
.- N
A
M ~
M
O p
C.
to
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r n
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27.if
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p
0 0
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n
M M
O O
U) p b
oCD
In M
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O CDo p
rn a,
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If
34
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O p
o
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569750 SRQann
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a
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LIP
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o +f `y��'j` > • r � f�
st Y �'Y�l` ,, �1M� • � .t �: �,..�- ` CIS � `�� rr� � Q o �•
., �� �' ��},�.. ,. * tel�,.� D 1 •A� - ;,ta^ _ ja���a� T �v1•� � ,
n T kw •', p..
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+- -1 v-
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0
' GJ
Y" /•i • ' .�fall3• ((, 11 J f �Q3-• Gr`.1 6.r1 C�:i �p C� See,,,,
�` �L•.• N' A* . d� 1 {'
tow-
30,
yill
u^t K ;
-1 `^ r •, ., S; . y� b- ti`rly --•B-3 if .., �� it 04
r 1 r t. r' ',-R-GIRRCR•C•OR• .R. •e - Y
--JIFS� v - C � fE. L._ r' �E .� z �1 r •,fE�al� �� 0.
eca•snn
econnn
pj iJ
R6
f-E d721
• 'fL uJ .' r SSSSIIIi � � ~
li
.. Ya. FF'td173C
O
1!f
co
co
r-
M
3
ft
n
D
0
Legend
■asa•
1 , Site Boundary
® Boring
® Infiltration Test
® Boring & Infiltration Test
NIN
0 25 50 100 150 200
Feet
JV.7• JV
DoaUuu
116'1452w
559350
569900
DESCRIPTIVE SOIL CLASSIFICATION
Soil classification is based on ASTM Designations D 2487 and D 2488 (Unified Soil Classification System). Information on each boring
log is a compilation of subsurface conditions obtained from the field as well as from laboratory testing of selected samples. The
indicated boundaries between strata on the boring logs are approximate only and may be transitional.
SOIL GRAIN SIZE
U.S. STANDARD SIEVE
12" 3" 3/4" 4 1 n an qnn
BOULDERS
COBBLES
GRAVEL v SAND v
,
SILT CLAY
COARSE I FINE I COARSE I MEDIUM I FINE
ouo 76.2 19A 4.16 2.00 0.42 0.074
SOIL GRAIN SIZE IN MILLIMETERS
0.002
RELATIVE DENSITY OF GRANULAR SOILS (GRAVELS, SANDS, AND NON -PLASTIC SILTS)
Very Loose
"N=04
RD=0-30
Easily push a 1/2-inch reinforcing rod by hand
Loose
N=5-10
RD=30-50
Push a 1/2-inch reinforcing rod by hand
Medium Dense
N=11-30
RD=50-70
Easily drive a 1/2-inch reinforcing rod with hammer
Dense
N=31-50
RD=70-90
Drive a 1/2-inch reinforcing rod 1 foot with difficulty by a hammer
Very Dense
N>50
RD=90-100
Drive a 1/2-inch reinforcing rod a few inches with hammer
`N=Blows per foot in the Standard Penetration Test at 60% theoretical energy. For the 3-inch diameter Modified California sampler,
140-pound weight, multiply the blow count by 0.63 (about 2/3) to estimate N. If automatic hammer is used, multiply a factor of
1.3 to 1.5 to estimate N. RD=Relative Density (%). C=Undrained shear strength (cohesion).
CONSISTENCY OF COHESIVE SOILS (CLAY OR CLAYEY SOILS)
Very Soft
"N=0-1
"C=0-250 psf
Squeezes between fingers
Soft
N=24
C=250-500 psf
Easily molded by finger pressure
Medium Stiff
N=5-8
C=500-1000 psf
Molded by strong finger pressure
Stiff
N=9-15
C=1000-2000 psf
Dented by strong finger pressure
Very Stiff
N=16-30
C=20004000 psf
Dented slightly by finger pressure
Hard
N>30
C>4000
Dented slightly by a pencil point or thumbnail
MOISTURE DENSITY
Moisture Condition: An observational term; dry, damp, moist, wet, saturated.
Moisture Content: The weight of water in a sample divided by the weight of dry soil in the soil sample
expressed as a percentage.
Dry Density:
The pounds of dry soil in a cubic foot.
MOISTURE CONDITION
RELATIVE PROPORTIONS
Dry .....................Absence
of moisture, dusty, dry to the touch
Trace ............. minor amount (<5%)
Damp................Slight
indication of moisture
with/some...... significant amount
Moist.................Color
change with short period of air exposure (granular soil)
modifier/and... sufficient amount to
Below optimum moisture content (cohesive soil)
influence material behavior
Wet....................High
degree of saturation by visual and touch (granular soil)
(Typically >30%)
Above optimum moisture content (cohesive soil)
Saturated ..........
Free surface water
LOG KEY SYMBOLS
PLASTICITY
'
Bulk, Bag or Grab Sample
DESCRIPTION
FIELD TEST
Nonplastic
A 1/8 in. (3-mm) thread cannot be rolled
Standard Penetration
at any moisture content.
Split Spoon Sampler
Low
The thread can barely be rolled.
(2" outside diameter)
Medium
The thread is easy to roll and not much
time is required to reach the plastic limit.
'
M
Modified California Sampler
High
The thread can be rerolled several times
outside diameter)
after reaching the plastic limit.
No Recovery
GROUNDWATER LEVEL
Water Level (measured or after drilling.)
Terms and Symbols used on Boring L
Water Level (during drilling)
Travertine Parcel-'1-I'M 35996
07711-31
Table 1
Fault Parameters
& Deterministic Estimates of Mean Peale Ground Acceleration (PGA)
Fault Name or
Seismic Zone .
Distance
front Site
(mi) (tun)
Fault
Type
Maximum
�tngnitude
Mmax
(Mw)
Avg
Slip
Rate
(mnt/Yr)
Avg
Return
Period
ON
Fault
Length
(lun)
Mean
Site .
PGA
(g)
Reference Notes: (1)
(2)
(3)
(4)
(2).
(2)
(2) ,
(5)
San Andreas - Southern
9.2
14.7
SS
A
7.7
24
220
199
0.33
San Jacinto (Hot Spgs - Buck Ridge)
12.2
19.6
SS
C
6.5
2
354
70
0.16
San Andreas - Banning Branch
12.3
19.9
SS
A
7.2
10
220
98
0.23
San Andreas - Mission Crk. Branch
12.3
19.9
SS
A
7.2
25
220
95
0.23
San Jacinto-Ania
. 16.5
26.6
SS
A
7.2
12
250
91
0.18
San Jacinto -Coyote Creck
18.1
29.2
SS
B
6.8
4
175
41
0.13
Blue Cut
21.0
33.8
SS
C
6.8
1
760
30
0.12
Burnt Mtn.
24.6
39.6
SS
B
6.5
0.6
5000
21
0.09
Eureka Peak
25.5
41.1
SS
B
6.4
0.6
5000
19
0.08
San Jacinto - Borrego
28.1
45.3
SS
B
6.6
4
'175
29
0.08
Earthquake Valley
35.6
56.4
SS
B
6.5
2
351
20
0.06
Morongo
'35.7
57.4
SS
C
6.5
0.6
1170
23
0.06
Brawley Seismic Zone
35.8
57.7
SS
B
6.4
25
24
42
0.06
Pinto Mountain
37.3
60.0
SS
B
7.2
2.5
499
74
0.09
Emerson So. - Copper Mtn..--.
38.3
61.6
SS
13
7.0
0.6
5000
54
0.08
Pisgah -Bullion Mtn. -Mesquite Lk
39.3
63.2
SS
B
7.3
0.6
5000
89
0.09
San Jacinto -San Jacinto Valley
39.6
63.8
SS
B
6.9
12
83.
43
0.07
Landers
39.7
63.9
SS
B
7.3
0.6
5000
83
0.09
GlSillOrC4ulian
39.8
64.0
-SS
'A
7.1
5
340
76
0.08
Elmore Ranch
43.4
69.9
SS
B
6.6
1
225
29
0.05
L-"lsinore-Coyote Mountain
44.7
72.0
. SS
B
6.8
4
625 ..
39
0.06
North Frontal I"ault Zone (fast)
45.8
73.6
RV
B
6.7
0.5
1727
27
0.07
Superstition Mtn. (San Jacinto)
46.2
744'
SS
B
6.6
5 • .
500 .
24.
0.05
E-1sinore- Temecula
46.9
.75.4
'SS
B
6.8
5
240
43
0.05
Superstition Hills (San Jacinto)
47.2
76.0
SS
B
6.6
4
250 .
23
0.05
Johnson Valley (Northern)
50.5
81.3
SS
B
6.7
0.6
5000
35
0.05
Calico - Hidalgo
52.0
83.6
SS
B
7.3
0.6
5000
95
0.07
Lonwood-Lockhart-Old Woman Spigs
56.3
90.5
SS
B
7.5.
0.6
5000
145 .
0:07
North Frontal fault Lone ( West)
56.4
90.8
RV
1.3 •
7.2
1
1314
50
0.07
Weinert (Superstition Hills),
59.5
95.7
SS
C-
6.6
4
250-!2;;y�
. 0.04
Imperial61.8
99.4
SS
A
7.0
20
79
62
0.05
I. Jennings (1994) and California Geologic Survey (CGS) (2003)
2. CGS (2003), SS = Strike -Slip, RV Reverse, DS = Dip Slip (normal), B•f = Blind'fhntst
3. 2001 CBC, where'fype A faults: Mmax> 7 & slip rate>5 nun/yr & Type C faults: Mmax <6.5 & slip rate<2 mm/yr
4. CGS (2003)
5. The estimates of the mean Site PGA are based on the following attenuation relationships:
Average of: (1) 1997 Boore, Joyner & Fumal; (2) 1997 Sadigh et at; (3) 1997 Campbell, (4) 1997 Abrahamson & Silva
(mean plus sigma values are about 1.5 to 1.6 times higher)
Based on Site Coordinates: 33.605 N Latitude, 116.247 W Longtude and Site Soil Type D
EARTI-I SYSTEMS SO(J7'NWEST
a
GRAPHIC
LETTER
MAJOR DIVISIONS'
SYMBOL
SYMBOL
TYPICAL DESCRIPTIONS
Well -graded gravels, gravel -sand
CLEAN
GW
mixtures, little or no fines
GRAVELS
r:'r:'r:'rr:•r:'r:'r:•
< 5% FINES
GRAVEL AND
r .r r••r• r• r• r• r
.•..•..•..•..• .•,.• .•.
7�r;r;.r;r�r�r�r�
-
GP
Poorly -graded gravels, gravel -sand
GRAVELLY
irk �• :r� r�:r� r�:r•
mixtures. Little or no fines
.
SOILS
'
GM
Silty gravels, gravel -sand -silt
COARSE
More than 50% of
GRAVELS
s
mixtures
GRAINED SOILS
coarse fraction
WITH
WITH FINES
retained on No. 4
> FINES
sieve
GC
Clayey gravels, gravel -sand -clay
mixtures
SW
Well -graded sands, gravelly sands,
SAND AND
CLEAN SAND
little or no fines
SANDY SOILS
(Little or no fines)
< 5%
SP
Poorly -graded sands, gravelly
More than 50% of
sands, little or no fines
material is larger
than No. 200
sieve size
SAND WITH FINE
SM
Silty sands, sand -silt mixtures
More than 50% of
(appreciable
coarse fraction
amount of fines )
passing No. 4 sieve
>12%
$C
Clayey sands, sand -clay mixtures
Inorganic silts and very fine sands,.
ML
rock flour, silty low clayey fine sands
or clayey silts with slight plasticity
Inorganic clays of low to medium
FINE-GRAINED-
LIQUID LIMIT
SOILS
LESS THAN 50
CL
plasticity, gravelly clays, sandy
clays, silty clays, lean clays
i
OL
Organic silts and organic silty
9 9
clays of low plasticity
SILTS AND
Inorganic silty, micaceous, or
CLAYS'
MH
diatomaceous fine sand or
Silty soils
50% or more of
material is smaller
LIQUID LIMIT
i
CH
Inorganic clays of high plasticity,
than No. 200
GREATER
�
j
fat clays
sieve size
THAN 50
OH
Organic clays of medium to high
plasticity, organic silts
.
• -
HIGHLY ORGANIC SOILS
.rrrrrrrrrrrr
ovvv.>a rrrrrr
aaarrraarraa
pT .
Peat, humus, swamp soils with
araryraaanrY
high organic contents
.rrrrrrr,Y.rrrr
VARIOUS SOILS AND MAN MADE MATERIALS
Fill Materials
MAN MADE MATERIALS
Asphalt and concrete
Soil Classification System
Earth Systems`
'
Southwest
OEarth Systems
W7 .Southwest 79-811 H Connny Club Drive, LXdSo, CA .
Phone (760)345-r588,Fax (760)345-7315
Boring No.: B-1
Exploration Date: November 19, 2008
Project Name: Travertine Parcel, TI'M 35996, La Quinta, CA
Drilling Method: 8" FISA
File Number: , 07711-31
Equipment Type: Mobile B61 HDX w m /Auto Hamer
I3ofing Location: See Figure 2 Elevation -11' MSL
Logged By: Joseph i3. McKinney
Sample
yp
Type
Penetration
J
o
61
,
Description of Units I age 1 of--] I
v
Resistance
o
rn
N
C
q Q
y
•o
Note: The stratification lines shown represent the
p
(131ows/6"
rn
G `
r;
approximate boundary bct%vecn soil and/or rock types Graphic'Crend
N
p
V
and the transition may be gradational. 131Ow Dry
Count Density
1-7
SM
SILTY SAND: light olive gray, dense, damp to
_
7,11,22
Its
4
moist, fine to coarse grained sand with silt
_ 5
12,13,15
113
2
Sp
SAND: moderate olive brown, medium dense, damp
-
to moist, fine to coarse grained sand with trace
SW
-- 10
8,11,13
112
2
gravel
-
24,31,40
_ _. _ _ __ _
WELL GRADED SAND: moderate olive brown,
8 12 12
SP/SM —
121
5
15
4 4
medium dense, damp to moist, fine to coarse
I
grained sand with gravel, cobble lenses
20
5 5 7
SAND WITH SILT: light olive gray, medium
-
dense, dry to darnp, fine to coarse grained sand with
silt, trace of gravel, 4-inch lenses of silty sand
25
` 30
Boring completed at 21.5 feet
13ackfilled'with cuttings
No groundwater encountered
— 35
— 40
— 45
— 50
— 55
-- 60
— 65
— 70
— 75
— 80
— tt5
_
0Earth Systems
Southwest 79-81113 Country Club 13rive, Aennuda Dunes, CA
Phone(760)345-I SBS_Va. n601145.711i
Boring No.: B-2
Exploration Date: November 20, 2008
Project Name: Travertine Parcel, 77M 35996, La Quinta, CA
Drilling Method: 8" HSA
File Number: 07711-31
Equipment Type: Mobile B61 I•IDX w/Auto 1•Iammcr.'
Boring Location: See Figure 2 Elevation -2T MSL
Logged By: Joseph E, McKinney
v
Sample—
r c
yp
Pench•ation
Pa e 1 of 1
Description of Units g
o
Resistance
o
E
Q
= �
p a
E!
•= r-i
Note: 'rhe stratification lines shown represent the
0
A
1
p
F„ q
N
(131ows/G")
>,
��
6a
2 o
U
approximate boundary between soil and/or rock types Graphic Trend
and the transition may be gradational. Blow Dry
_ Count Density
�1
10,14,34
SW-SM
123
3
WELL GRADED SAND WI'T H SILT: light olive
-
8,13,7
110
3
gray, dense, dry to damp, with cobbles
:,
SW
—5
'
4,5,5
l02
14
7
SW-SM
WELL GRADED SAND: light olive gray, medium
-
7,11,16
102
3
dense, damp to moist, with trace of cobbles
- 10
17,12,13
---
2
WELL GRADED SAND WITH SILT: light olive
gray, dense, dry to damp, with cobbles
- 15
(]
30,15,17
- 20
15,24,30
93
q
SM
SILTY SAND: light olive gray, very dense, dry,
fine to coarse grained sand
ML
- 25
4,8,19
•
-"—
SW-SM
SILT': yellowish gray, hard dty
Y g Y> >
- 30
WELL GRADED SAND WITH SILT: yellowish
SM
6,%12
gray, dense, dry, fine to coarse grained sand with
silt, trace of gravel
- 35
8,10,18
-
SILTY SAND: yellowish gray, dense, dry, fine to
coarse grained sand with I" well graded sand tense,
- 40
6" ML tense at tip
SW-SM
EN
9,13,26
WELL GRADED SAND WITH SILT: yellowish
I
- 45
gray, dense, dry, fine to coarse grained, with I" well
_
SM
[j;
12,18,21
graded sand tense, 3" ML lense
- 50
I
SILTY SAND: yellowish gray, very dense, dry, fine
16 24,29
to coarse grained sand with silt, 3" silt lenses, 3".
sand lenses, trace gravel
- 55
9,14,17
-
ML
SANDY' SILT: yellowish gray, dense, dry to damp,
fine grained sand, 4" dusky yellow silty clay tense, .
- 60
El
12 1a 20
trace of gravel
- 65
Boring completed at 61.5 feet
No groundwater encountered
70
Perforated PVC Pipe set with sock in boring; back(illed
with gravel
75
80
85
--
Earth Systems
WO Southwest 79-81111 Cowury Chub Drive, Bcnnuda Dunes, CA
Ph.n f7AM IAS_I "R Gnv /78(1\ 7AiR l <
Boring No.: B-3
1:xploration Date: November 19, 2008
Pro ect Name: Travertine Parcel, 7TM 35996, La Quinta, CA
Drilling Method: 8" HSA
Pile Number: 07711-31
Equipment Type: Mobile B61 14DX w/Auto Hammer
Boring Location: See Figure 2 Elevation -13 MSL
Logged By: Joseph E. McKinney
v
Sample
I'ypc
Penetration
E
- -
Description Of Units
Page 1 of 1
a
w
,3
Resistance
o
cn
N
q a
o
- c
Note: The stratification lines shown represent the
N
A
a
F_ 0
a o
(131o\vs/G")
>,
cn
�,�-
� o
approximate boundary between soil and/or rock types
Graphie'rrend
ct
N
A
V
and the transition may be gradational.
Blow Dry
Count Densily
Sl"l
SILTY SAND: yellowish gray, fine to coarse
-
N`
{ 6,6,1 l
7,12,21
116
I
grained sand, medium dense, dry, gravel near top
5
--
1
Sw-SM
GRAVELLY SAND WITH SILT: light olive gray,
dense, dry, fine to coarse grained sand, cobble in
- 10
��
8,17,19
I
sample
6,7,13
]
_
1
20,22.34
t
- 15
5,6,7
$p_SM
_
SAND WITH SILT: yellowish gray, medium dense,
fine to coarse grained sand, silty sand lense at tip
- 20
3,5,7
1.5" gravel lease
- 25Oj
7,7 8
SM
--
SILTY SAND WITH GRAVEL: yellowish gray,
medium dense, dry to damp, fine to coarse grained
- 30
s 8 t 7
sand, trace gravel
MI.
SILT: yellowish gray, dense, dry to damp, fine to
- 35
medium grained sand
_J
Boring completed at 31.5 feet
- 40
Backlilled with cuttings
- 45
No groundwater encountered
- 50
- 55
- 60
C5
70
75
80
85
Earth Systems
`Southwest 79-811B Cotuitry Club Drivo, nemwda Dimes, CA
Phone (760) 345-1588, Fax (760) 345-7315
Boring No.: B-4
Exploration Date: November 19, 2008
Project Name: 'Travertine Parcel, 'ITM 35996, La Quinta, CA
Drilling Method: 8" 14SA
File Number: 07111-31
Equipment Type: Mobile 1361 FIDX w/Auto I•lammer
Boring Location: See Figure 2 Elevation -15 MSL
Logged By: Joseph 17. McKinney
U.Type
Sample
Penetration
N
2 �
Description of Units M Page I of 2
A
Resistance
vUi
p o
.!a r
Note: The stratification lines shown represent the
m
Q
F p
0
(Blows/6")
�,
ai
Z
5 o
approximate boundary bctwcen soil and/or rock types Graphic Trent)
m N
Ca
U
and the transition may be gradational.. Blow Dry
Count Mnsity
SM
SILTY SAND: light olive gray, dense, dry, fine to _
10,15,23
105
1
medium grained sand, with gravel at top
I
5,12,17
T.
117
_5
- 10
7,8,13
,l
-
1
S1'-SM
SAND WITH SILT: yellowish gray, medium dense,
dry, fine to coarse grained sand with silt, trace of
Sw-Slut
8,15,12
1
gravel
-
112 14 22
WELL GRADED SAND WIT SILT: yellowish
gray, medium dense, dry, with silt,
- 15
668
,
S1 SM
SAND WITH SILT: light olive gray, medium
dense, dry, fine to coarse grained sand with silt, 3"
gravel lense
- 20
3,6,11
ML
_
SILT: yellowish gray, sitff, dry, fine to coarse
grained sand with trace of gravel
- 25
7,8,13
SM
SILTY SAND: yellowish gray, medium dense, dry,
fine to medium grained, trace of gravel
- 30
GG;IG
SM
SILTY SAND: yellowish gray, medium dense, dry,
fine grained sand, trace of gravel, 2" silty clay
lenses
-35
7813
T.
gM"
SILTY SAND: yellowish gray, medium dense, dry,
fine to corrse grained sand, 4" and 1" silty clay
lenses
- 40
7,16,19
NIL
SANDY CLAYEY SILT: dusky yellow, hard, dry,
fine grained
Sw-SM
WELL GRADED SAND WITH SILT: yellowish
- 45
gray, very dense, dry, fine to coarse grained sand,
15, 8,24
trace of gravel
Earth Systems —
WON, Southwest 79-811 B Counlry Club Drive, Bennuda Dines, CA
Phone (760) 345-1588. Fax (760) 345.7315
Boring No.: B-4
Exploration Date: November 19, 2008
Project Name: ,travertine Parcel, TfM 35996; La Quintal CA
Drilling Method: 8" I -)SA
File Number: 07711-31
f.•.quipment Type: Mobile1361 FIDX w/Auto Hammer
Boring Location: See Figure 2 Elevation -15 MSL
—
Logged By: Joseph E. McKinney
v
Satnple
Type
Penetration
�'
Description Of Units Page 2 of
Resistance
"
E
v
•-
Note: The stratification lines shown rcp resent the
G
�.
(Blows/6")
cn
Z
0 o
approximate boundary between soil and/or rock types Graphic'1'rend
a. 0
Q
U
and the transition may be gradational. 1310w Dry
Count DGuily
50
sM/Ml-
SILTY SAND: dusky yellow, dense, dry,. fine to
coarse grained sand to fine to coarse sandy silt,
trace of gravel
- 55
WELL GRADED SAND WITH SILT: yellowish
I0,13,27
sw-sM
gray, very dense, dry, fine to coarse grained sand
with silt, 3" silt lenses at tip, trace of gravel
- GO
_
12,20,38
ML
--
SANDY SILT: dusky yellow, hard, dry, fine to
coarse grained sand, trace of gravel, silty sand
lenses at tip
- 65
- 70
Boring completed at 61.5 feel
No groundwater encountered
Perforated PVC Pipe with sock set in boring; hole caved
around pipe; no gravel; backfilled
- 75
- 80
- 85
_
0 Earth Systems
Southwest 79-81113 Comtry Chub Drive, Bernunla Dunes, CA
Phone (760) 345-1588, ru (760).345-7315 '
Boring No.: B-5
Exploration Date: November 19, 2008
ProjectName: Travertine Parcel,'I-I'M 35996, La Quinta, CA
Drilling Method: 8" HSA
Pile Number: ' 07711-31
Equipment Type: Mobile B61 FIDX w/Auto I•lammer
Boring Location: See Figure 2 Elevation -16 MSL-
Logged By: Joseph 17. McKinney
Sample
Type
Penetration
Page f I
Description of Unitsi o
n
a
d
Resistance
E
q a
N
.
Note: •1'he stratification lines shown represent the
A
1
0
o
(Blowsl6")
>,
a
��
o
o.
approximate boundary between soil and/or rock types Graphic'I'rend
A
U
and the transition may be gradational. Blow Dry
Count Density
WELL GRADED SAND WITH SILT: light olive
sw-sM
6,8,9
7
gray, medium dense, dry, gravel
— 5
6,8,13
--
1.
gravel
- 10
7, I2,16
t
, -.
v
Sp-sM
-
1
-
SAND WIT14 SILT: light.olive gray, medium
16,20,23
123
1
dense, dry, fine to coarse grained sand, trace of
d
15
N
10,18,38
92
2
gravel
SW-SM
=
9,9,25
GRAVELLY SAND WITH SILT: yellowish gray,
- 20
-
0
1
4 7 9
M1"
very dense, dry, fine to coarse grained sand, cobbles
SILT: light olive gray, very stiff, dry, some with 1"
- 25
silty clayey tense, gastropod shells
- 30
- 35
Boring completed at 21.5 feet
No groundwater encountered
- 40
Perforated PVC Pipe with sock set in boring; hole cavcd
around pipe; no gravel; backlilled
- 45
- 50
- 55
- 60
- 65
- 70
- 75
- 80
- 85
EARTH SYSTEMS CONSULTANTS SOUTHWEST
DOUBLE RING INFILTRATION TEST DATA (ASTM D3385)
PROJECT: Travertine Parcel - TTM 35996
JOB NO: 07711-3.1
LOCATION: 1-1
Depth
of
Volume
Constants
O.D.
I.D.
Area
Liquid
Constant
in.)
in.
(sq cm)
(cm)
(cc/cm)
Inner Ring
12.4
12.0 1
730
11
670
Outer Ring
23.8
23.4 1
1993
1 11
670
Conversions:
1 in/hr = 2.54 cm/hr
5.89 gal/sf/day = 1'cm/hr
Infiltration Rate (cm/hr): [Flow (cc) x (60 minlhr)]/[Area (sq cm) x Incr Time (min)]
I es
t ti : KH Penetration of rings (cm): Inner: 14 Outer: 15
Trial
.No.
Date
Time
Elapsed Time
Flow Readings
Liquid
Temp
Incr. Infiltr. Rate
Inner
I Outer
Incr.
Total
Reading
Flow
Reading
Flow
Inner
Outer
1
S
11 /21 /08
8:25 AM
(min)
(cm)
67.0
cc
(cm)
68.5
(cc)
F
(cm/hr)
(cm/hr)
I 2
E
$
8:40 AM
15
15
66.9
67
65.5
2010
0.4
4.0
1 Infiltration Test Results
8.40 AM
66.9
65.5
4.5
E
8:55 AM
15
1 30
66.4
335
1 63.3
1474
1.8
3.0
3
S
8:55 AM
66.4
63.3
4.0
E
9:10 AM
15-
45
65.8
402
60.7
1742
2.2
3.5
4
S
9:10 AM
65.8
60.7
3.5
E
9:25 AM
15
60
65.4,
268
57.9
1876
1.5
3.8
5
S
9:25 AM
65.4
57.9
3.0
E
9:55 AM
30
90
64.5
603
1 53.4
3016
1.7
3.0
E
6
S
9:55 AM
64.5
53.4
22.5
E
10:25 AM
30
120
62.5
1340
49.4
2680
3.7
2.7co
7
S
10:25 AM
.
62.5
49.4
° z:o
E
10:55 AM
30
150
.61.4
737
45.2
2815
2.0 1
2.8
8
S
10:55 AM
61.4
45.2
S 1.5
E
11:25 AM
30 1
180
60.4
670
40.7
3016
1.8
3.0
9
S
11:26 AM
60A .
60.3
1.0
E
12:26 PM
60
241
59.0
638
51.1
6165 1
1.3
3.1
10
S
12:26 PM
59.0
51.1
0.5
E
1:26 PM
60
301
51.4
1072
42.0
6098
1.5 1
3.1
11
S
1:26 PM
57.4
42.0
0.0
E 2:26 PM 60 1 361 55.0 1608 1 32.8 6165 2.2 3.1 0 60 120 180 zoo 300 360
Hasped Time (min.) 1
Stabilized Infiltration Rate: 1.8 cm/hr = 0.7 in/hr - 10 gal/sf/day
Table 2 - Initial Estimated Conductivities
Boring 2
r Boring 4.
Reference Elevation
current gs
current gs
Interval 1
Top
25
25
Bottom
35
30
Thickness,
10
5
D,o Size (mm)
0.09
0.04
K Value (cm/sec)
8.1 E-03
1.6E-03
K Value (ft/day)
23.0
4.5
K Value (gal/day/fe)
172
34
Interval 2
Top
40
45
Bottom
55
50
Thickness
15
5
DIo Size (mm)
0.05
0.06
K Value (cm/sec)
2.5E-03
3.6E-03
K Value (ft/day)
7,
10
K Value (gal/day/ft2)
53
77
Interval 3
Top
d S"
55
Bottom
r60
Thickness
1�
5
D,o Size (mm)
99
0.06
K Value (cm/sec)
r
n
3.6E-03
K Value (ft/day)
1;
10
K Value (gal/day/ft2)
r
'
77
Table 3 - Drywell Design and Infiltration Model
Reference Elevation
Boring 2
Boring 4
Current gs
Current s
Drywell Construction Depth
Main Drywell
Pilot Hole
20
55
20
60
Upper Soil Interval
Top
feet
25
8
Bottom
feet
35
30
Thickness
feet
10
22
Estimated K Value
ft/da)
22.9
2.5
al/da /ft2
172
20
Model Type (see below)
C
C
Estimated Disposal Capacity
(gal/day)
103,184
11;098
Estimated Disposal Capacity
AF/da
0.32
0.03
Deeper Soil Interval (if an
Top
feet
.40
45
Bottom
feet
55
50
Thickness
feet
15
5
Estimated K Value
ft/da)
7.1
10.3
al/da /ftz
53
77
Model Type (see below)
C
C
Estimated Disposal Capacity
(gal ay)
80,408
58,648
Estimated Dis osal Ca acit
AF/da
0.25
0.2
Deeper Soil Interval (if an
Topfeet
h. ter, :..s:
is€k
55
Bottom
feet,'
60
Thickness
feet
5
Estimated K Value
ft/da_'
10.3
(gal/day/if)�_.
77
Model Type (see below)
F;
' ,�•�� I.;.;_;;'�"��
C
Estimated Disposal Capacity
(gal/day )a
rrMi
75,404
Estimated Disposal Ca a
AF/da
r. Y���q'
Y.�,LZK55'
0.2
Model Types A = Unconfined with no underlying barrier
B = Unconfined with underlying barrier
C = Overlying and underlying barrier
APPENDIX B
Laboratory Test Results
EARTH SYSTEMS SOUTHWEST
File No.: 07711-31 December 30, 2008
Lab No.: 08-0465
UNIT DENSITIES AND MOISTURE CONTENT ASTM D2931 & D2216
Job Name: Travertine Parcel, TTM -35996
Unit
Moisture
USCS
Sample
Depth
Dry
Content
Group
Location,
(feet)
Density (pco
. (%)
Symbol
131
2
115
.4
SM
Bl
4
1.13
2
SP
B1
9
112
.2
SP
B1
13
121
5
SW
B2
1
123
3
SW-SM
B2
3
110
3
SW
B2
6'
102
14
SW-SM
B2
8
102
3
SW-SM
B2
10
---
2
SW-SM
B2
20
93
4
ML
B3
2
116
1
SM
B3
4
---
T
SM
B3
9
---
1
SP-SM
B3
11
---..
1
SP-SM
B3
13
---
1
SW-SM
B4
1..
105
1
SM
B4
3
117
1
SM
B4
9.
---
1
SP-SM
B4
• 11
---
1
Sw-SM
B5
2
---
7
SP-SM
B5
4
---
1
SP-SM
B5
10.
---
1
SP-SM
B5
14
123
1
SW-SM
B5
17
92
2
ML
EARTH SYSTEMS SOUTHWEST
File No.:.07711-31
December 30, 2008
Lab No.: 08-0465
PARTICLE SIZE ANALYSIS
ASTM D-422
Job:Name: Travertine Pareel,.TTM 35996
Sample ID: B2 @ 25 feet
Description: Yellow Brown Well Graded Sand w/Silt (SW-SM)
Sieve Percent
Size Passing
1-1/2" 100
1" 100
3/4" 100
1/2" . 98
3/8" 98
#4 93
#8 83
#16. 69 % Gravel:
7
#30 45 % Sand:
85
#50 25 % Silt:
7
#100 14 % Clay (3 micron):
1
#200 8 (Clay content by short hydrometer
method)
100 ,
� I �
90
80
70
go
30
I
20
10
0 Lf L iLLLI
10 1 0.1 Particle Size ( mm) 0.01 0.001
EARTH SYSTEMS SOUTHWEST
File No.: 07711-31
December 30, 2008
Lab No.. 08-0465
PARTICLE SIZE ANALYSIS ASTM'D-422
Job Name: Travertine Parcel, TTM 35996
Sample ID: B2 @ 30 feet
Description: Yellowish Brown Silty Fine to Coarse Sand w/Gravel (SM)
Sieve
Percent
Size
Passing
1-1 /2"
1.00
1"
100
3/4"
89
1 /2"
89
3/8"
89.
#4
84
#8
78
#16.
68 % Gravel: 16
#30
54 % Sand: 59
#50
43 % Silt:- 17
#100
32 % Clay (3 micron): 8
#200
25 (Clay content by short hydrometer method)
100
so
so
70
&0
N
30
go
a
30
20
10
0
10 1. 0.1 0.01 0.001
Particle Size (mm)
EART14 SYSTEMS SOUTHWEST
Pile No.: 07711-31
December 30, 2008
Lab No.: 08-0465
PARTICLE SIZE ANALYSIS
ASTM D-422
Job Name: Travertine Parcel, TTM 35996
Sample ID: B2. @ 40 feet
Description: Brown Well Graded Sand w/Silt & Gravel (SW-SM)
Sieve Percent
Size Passing
1-1 /2" 100
1" 100
3/4" 100
1/2" 97
3/8" 96
#4 89
#8 76
#16 63 % Gravel:
11
#30 46 % Sand:
77
#50 30 % Silt:
12
# 100 •1,8 % Clay (3 micron):
0
#200 12 (Clay content by short hydrometer method)
100
90
80
70
&o
c
a0
Po
a
30
20
10
0
10 1 0.1 Particle Size (mm) 0.01 0.001
EARTH SYSTEMS SOUTHWEST
File No.: 07111-31
December 30, 2008
Lab No.: 08-0465
PARTICLE SIZE ANALYSIS
ASTM D-422
Job Name: Travertine Parcel, TTM 35996
Sample ID: B2 @ 45 feet
Description: Yellowish Brown Silty. Fine to Coarse Sand w/Gravel (SM)
Sieve
Percent
Size
Passing
1-1/2"
100
1"
100
3/4"
100
1/2"
98
3/8"
97
#4
92
#8
81
#16
70 % Gravel:
8
#30
56 % Sand:
78
950
40 % Silt:
12
#100
24 % Clay (3 micron):
2
#200
14 (Clay content by short hydrometer method)
100
90
80
70
,q0
c
ao
90
a_
30
20
10
0
10 1 Particle Size ( mm) 0.01 0.001
EARTH SYSTEMS SOUTHWEST
File No..: 07711-31
December 30, 2008
Lab No.: 08-0465
PARTICLE SIZE ANALYSIS
ASTM D-422
Job Name: Travertine Parcel, TTM 35996
Sample ID: B4 @ 25 feet
Description: Brown,Silty Fine to Coarse Sand w/Gravel (SM)
Sieve Percent
Size Passing
1-1/2" 100
1 ff 100
3/4" 100
1 /2" 95
3/8" 95
#4 92
#8 85
# 16 76 % Gravel:
8
#30 57 % Sand:
78
#50 37 % Silt:
11
#100 24 % Clay (3 micron):
3
#200 14 (Clay content by short hydrometer method)
100
90
80
70
30
c
810
a
30
20
10
0
i
10 1 0.1 Particle Size ( mm) 0.01 0.001
EARTH SYSTEMS SOUTHWEST
File No.: 07711-31
December 30, 2008
Lab No.: 08-0465
PARTICLE SIZE ANALYSIS
ASTM D-422'::
Job Name: Travertine. Parcel; TTM 35996
Sample ID: B4 @ 35 feet.
-
Description: Brown Silty Fine to Medium Sand (SM) .
Sieve Percent
Size Passing
1-1 /2" 100
11, 100
3/4" 100
1 /2" 100
3/8" 100
#4 98
#8 94
#16 88 % Gravel:
2
#30 79 % Sand:
63
#50 65 % Silt:
35
#100 49 % Clay (3 micron):
0
#200 35 (Clay content by short hydrometer method)
100
90
80
70
&0
c
.N
30
C
PO
a
30
N1
10
a
i
Particle Size ( MM) 0.01 0.001
EARTH SYSTEMS SOUTHWEST
File No:: 07711-31
December 30, 2008
Lab No:: 08-0465
PARTICLE SIZE ANALYSIS
ASTM D-422
Job Name: Travertine Parcel, TTM 35996
Sample ID: B4 @ 45 feet
Description: Yellowish Brown Well Graded Sand w/Silt (SW-SM)
Sieve Percent
Size Passing
14/2" 100
111 100 -
3/4" 100
1/2" 100
3/8" 100
#4 96
#8 87
#16 74 % Gravel:
4
#30 58 % Sand:
84
#50 39 % Silt:
10
#100 23 % Clay (3 micron):
2
#200 12 (Clay content by short hydrometer method) .
i
S0
V)
a0
c
PO
a
30
20
10
0
10 1 Particle Size ( mm) OA1 O.Q01
EARTH SYSTEMS SOUTHWEST
File No.: 07711-31
December 30, 2008
Lab No.: 08-0465
PARTICLE SIZE ANALYSIS
ASTM D-422
Job Name: Travertine Parcel, TTM 35996
Sample ID: B4 @ 55 feet
Description: Yellowish Brown Well Graded Sand w/Gravel (SW-SM)
Sieve
Percent
Size
Passing
1-1/2"
100
1"
100
3/4"
100
1/2"
100
3/8"
98
#4
96
#8
90
#16
81 % Gravel:
4
#30
65 % Sand:
84
#50
42 % Silt:
12
#100
22 % Clay (3 micron):
0
#200
12 (Clay content by short hydrometer method)
100
90
80
70
s0
in
3o
ci.
�o
n�.
30
20
10
0
10 1 Particle Size (mm)
0.1
0.01 0.001
EARTH SYSTEMS SOUTHWEST
Fide No.: 07711-31 December 30, 2008
Lab No.: 08-0465
CONSOLIDATION TEST ASTM D 2435 & D 5333
Travertine Parcel, TTM 35996
132 @ 20 feet
Yellowish Gray Silt (ML)
Ring Sample
2
1
0
-1
-2
r
rn -3
c -4
a)
c 5
z
V -6
c
m
as
-7
IL
-8
-9
-10
-11
-12
Initial Dry Density: 88.6 pcf
Initial Moisture; %: 3.9%
Specific Gravity (assumed): 2.67
Initial Void Ratio: 0.881
Hydrocollapse: 3.6% @ 2.0 ksf
% Change in Height vs Normal Presssure Diagram
—9 Before Saturation Hydrocollapse
Rebound
After. Saturation
......... . .....
.�-�
it
0.1 1.0 10.0
Vertical Effective Stress, ksf
EARTH SYSTEMS SOUTHWEST
File No.: 07711731 December 30, 2008
Lab No.: 08-0465
CONSOLIDATION TEST ASTM D 2435 & D 5333
Travertine Parcel, TTM 35996
135 @ 17 feet
Grey Fine Silt (ML)
Ring Sample
2
1
0
-1
-2
rn -3
c -4
m
-5
.c
U 6
c
a
-7
a
-8
-9
-10
-11
-12
Initial Dry Density: 90.4'pcf
Initial Moisture, %: 1.6%
Specific Gravity (assumed): 2.67
Initial Void Ratio: 0.844
Hydrocollapse:. 1.1 % @ 2.0 ksf
% Change in Height vs Normal Presssure Diagram
-* Before Saturation Hydrocollapse ■ After Saturation
* Rebound
0.1 1.0
Vertical Effective Stress, ksf
10.0
EARTH SYSTEMS SOUTHWEST
File No.: 07711-31 December 30, 2008
Lab No.: 08-0465
MAXIMUM DENSITY / OPTIMUM MOISTURE ASTM D 1557-91 (Modified)
Job Name: Travertine Parcel, TTM 35996 Procedure Used: A
Sample ID: 1 Preparation Method: Moist
Location: B 1 @ 1-4 feet Rammer Type: Mechanical
Description: Brown Pine to Coarse Sand w/Silt Lab Numbe 08-0465
& Gravel (SM)
Sieve Size % Retained
Maximum Density: 130 pef 3/4" 1.4
Optimum Moisture: 9% 3/8" 4.4
##4 9.0
140
135
130
125
0 115
110
105 -
100
0
!Ir
5 10 15 20 25
Moisture Content, percent
30 35
EARTH SYSTEMS SOUTHWEST
File No.: 07711-31 December 30, 2008
Lab No.: 08-0465
MAXIMUM DENSITY OPTIMUM MOISTURE ASTM D 1557-91 (Modified)
Job Name: Travertine Parcel, TTM 35996 Procedure Used:A
Sample ID: 2 Preparation Method: Moist
Location: BI @8-11 feet Rammer.Type: Mechanical
Description: Olive Will Graded Sand w/Gravel Lab N imbe 08-0465
(SW)
Sieve Size % Retained
Maximum Density: 128.5 pcf 3/411 4.3
Optimum Moisture: 8% 3/8" 9.5
#4 16.3
140
135
130
125
CL
120
0
115
110
105
r1111
I
I
----- Zero
sg
Air Voids Lines,
=2.65, 2.70, 2.75
100 -
1 0
5 10 15 20 25 30 35
Moisture Content, percent
EARTH SYSTEMS SOUTHWEST
Pile No.: 07711-31 December 30, 2008
Lab No.: 08-0465
MAXIMUM DENSITY / OPTIMUM MOISTURE AST'M D 1557-91 (Modified)
Job Name: Travertine Parcel, TTM 35996 Procedure Used: A
Sample ID: 3 Preparation Method: Moist
Location: B4 @ 1-4 feet Rammer Type: Mechanical
Description: Brown Silty Pine to Medium Sand Lab Numbe 08-0465
w/Gravel (SM)
Sieve Size % Retained
Maximum Density: 115 pef 3/4" 0.0
Optimum Moisture: 11.5% 3/8" 0.1
#4 1.0
140
135
130
125
110
105
100
IN
I
lull
No
loll
0 5 10 15 20 1 25
Moisture Content, percent
30 35
EARTH SYSTEMS SOUTHWEST
File No.: 07711-31
December 30, 2008
Lab No.: 08-0465
SOIL CHEMICAL'ANALYSES
Job Name: Travertine Parcel, TTM 35996
.lob No.: 07711-3 F
Sample ID: B1 B4
Sample Depth, feet: 1-4 1-4
Dl- RL
Sulfate, mg/Kg (ppm): 78 20
1 0.50
Chloride, mg/Kg (ppm): 51 28
0.20
pHj (pH Units): 8.70 8.20
1 0.41
Resistivity, (ohm -cm): 650 2,800
N/A N/A
Conductivity, (µmhos -cm):
I 2.00
Note: Tests performed by Subcontract Laboratory: '
Surabian AG Laboratory
DF: Dilution Factor
105 Tesori Drive
RL: Reporting Limit
Palm Desert, California 0211 Tel: (760) 200-4498
General Guidelines for Soil
Corrosivity
Chemical Agent
Aniount in' Soil
De yree.of Corrosivity
Soluble
0 -1000 mg/Kg (ppn) [ 0-.1%]
Low
Sulfates
1000 - 2000 mg/Kg (ppm) [0.1-0.2%)
Moderate
2000 - 20,000 mg/Kg (ppm) [0.2-2.0%) .
Severe
> 20,000 mg/Kg ( m) [>2.0%
Very Severe
Resistivity
1-1000 ohni-cm
Very Severe
1000-2000 ohm -cm
Severe
2000-10,000 ohni-cm
Moderate
10,000+ ohm -cm
Low
EARTH SYSTEMS SOUTHWEST