06-1176 (SFD) Geotechnical Engineering ReportLa Quinta, California 92253
Project The Hideaway - Lot 46.
53-783 Via -Palacio,
Quinta,'CalifoMiai
I a
•
Subject: Gpotechnical Update:
Ref: Report of ObservatibipS and'Testing ()Oriing Fine C rading prepared by Slaiden
Etgineering dated Aijgust 1 ,1200O, Pr
bject No. 544-2199y Report No. 4-225.
Ceote6nical Updatem'prepvo bV- Madden Engin" dated February 25. 2003,
Pioject No.;: 544-2199,:Report: No. 61M-406.
Report of Testing and Observation Duiing Rough Gra
dii g.prepared by Earth Systems
Southwest dated August 28,1602; -File ; No- 07117-11,,Report No- 01-07-718_
Geotechnical dated llnginem"Vg-.Rcsyst'ems Consultants
port preoreO by bath
September'.22, 2000, File NoA7117-1 0, keport No 004)9 -772 -
As requested, we have reviewed the ibove'refer'enced geotechnical as they relate to the
design and i onstructi'on of theprop-oso single family residence.- Ilie project site! is identified as
Lot 226 within:Phasi 18 of t1k Hideaway, �o# bub development d La Quinta,
OP t in the City f
California. It is our kinderstanoingi that the pro�dsed residence will be a relathielj lightweight
wood frame structure supp6roby conventional Apreaallow'; d ifcAings and concrete slabs on
grade.
The lot was! previotL41y gradedi
unng
.d the touA trading -of the Hideaway:site and was
recently regrad6d. The roughgra dinj includedincludedoverexciavki(in of the'native surface soils along
with 'the placeirient !of en eared! MU maieria I to construct th� building pads.. The recent
irIcluded Orocessing 'ffie surface fface $04 al6ng with 1111nor! cuts and fills
a to construct the
individual building pads.
Sorfie additional overexcavation was performed in aieas, where the
building envelopes vyere recu t figured Thi initial; site
;;;s marized in, the referenced
ng
Report of Obs"�,ons and i R46ugh Brading is
by rth Systems
.Testing :E)un
Soutfiwest and'the recent gradtng s�urnnd
in the Report of Observations and
Testing During Fine Grading prepared by our font'
r�7t,
January 6,2006: 2- Project, No. 544-6000
06-01-015
The referenced reports include recommendations pertaining to the construction of residential
structure foundations. Based upon our review of tate referenced reports, it is our opinion that the
structural values included in the referenced grading report remain applicable for the design and
construction of the proposed residential structure foundations.
Because the.lot has been previously graded, the remedial grading required at this, time should be
minimal. The building area should be cleared of surface vegetation~, scarified and moisture
conditioned prior to precise grading. The exposed surface should be compacted so that a
minimum of 90;percent relative compaction is attained prior to fill placement. Any fill material
should be placed in `thin lifts at near_ optimum. moisture Content and compacted to at least 90
percent relative compaction_.
Allowable Bearing Pressures:: The allowable bearing pressures; recommended in the grading
report prepared by':Sladden Engineering remain applicable. !Conventional shallow spread
footings should be bottomed into properly compacted fill materiala minimum of 12 inches below
lowest adjacent grade. Continuous. footings should be at least 12 inches wide acid isolated pad
footings should,be at least 2 feet wide. Continuous footings and isolated pad footings maybe
designed utilizing an'allowablc bearing pressure:of 2000 psf. An Alowable increase of 300 psf for
c--tch additi4nal.1 foot of width"and 300'psf for each additional 6 'inches of depth may be utilized
if desired. The maximum allowable bearing pressure should be 3000 psf. The recommended
allowable bearing pressures may be increased by one -Burd for wind and seismic loading.
The bearing soils are non -expansive. and :fall within the "yer}1 1'ow" expansion category in
accordance with Uniform Building Code (UBC): classification criteria. • Pertinent 1997 UBC
Seismic Design parameters are summarized on the attached, data sheet.
If you have questionsregarding ; this letter or: the referenced reports, please contact the
undersigned. !
Respectfully sui mittw, ' E
SLADDENIGINEEIiING
a' C 4g9 T
�9h,0%OE
Fip.i 'M
Brett L. Anderson
Principal Engineer
SEWpc
!�FCA�tFO�
Copies. !4/Albers Construction
i Sladden. ,Engineering
MR. JOHN LANE
S
C/O A & A ARCHITECTS
Aom
3080 BRISTOL STREET
®®
• COSTA MESA, CALIFORNIA 92626
GEOTECHNICAL ENGINEERING REPORT
PROPOSED SINGLE-FAMILY RESIDENCE
LOT 226 AT THE HIDEAWAY
53-783 VIA PALACIO
LA QUINTA, CALIFORNIA
April 1.4, 2005
02005 Earth Systems Southwest
Y
Unauthorized use or copying of this document is strictly prohibited '
without the express written consent of Earth Systems Southwest.
File No.: 09902-02
' 05-04-747
Earth Systems , , .:.' - '5 •
`
Southwest 79-811 B Country Club Drive
_ •
y
-• I Indio, CA'92203'
g,
•+
(760) 345-1588
,,. (800)924-%015
• - . • FAX (760) 345-7315
T.
•..
File Nod: 09902=02
April 1'4; 2005 - -
w
-
MrAohn Lane y
f
c%o A& A Architects w
•
3080 Bristol Street r
'
Costa Mesa, Cali fornia 92626 ' t
Attention: Mr. Keith Reed
Project: _ Proposed Single -Family Residence
•.'-Lot 226 at The Hideawav: 53-783,Via Palacio
La' Qui.nta, California
r
h Subject:.. , Geotechnical Engineering Report
r
...Dear Mr.'Reed: - ,y
We take pleasure in .present. this geotechnical engineering reportprepared for the proposed—� <
#.,
single'family residence to be located at 53-783 Via Palacio, Lot 226 within The'Hideaway '
Country Club, in the City of,.La Quinta',-Riverside County, California. • ' a{ '+.
`
' This. report presents out findings and reconzme.ndat.ions for site grading and foundation design; r.w
incorporating the information provided,to our ofLice. The site is suitable Tor -the proposed
f
h
development, provided- the recommzndations` ih• thin. report are followed in design' and
construction. In general, the upper soils should'be compacted to improve bearing capacity and
reduce the potential for differential settlement. The site is sub ect to stron round motion from
,_•the. San Aridreas fault. .This report should stand as a.whole and no part of the report•shoul.d,,be '
excerpted or. used to the exclusion of any other part.' Y - ;'�•3
This report completes -our scope of services in acc6rdance with* our agreement dated jan.uar} 25, ,
2005,'and authorized on Marclt.l0, 2005. Other_se`rv:ices that mai- be required; such as plan. ,.
`
review and Grading observation. are additional seryices-and gill be billed �accordin to our.Fee
N'
Schedule in effect•at the time services are -provided. -Unless requested in writing, the client is + ''
responsible .for distributing this rep' rt. to the appropriate governing,agency or other members of s
the',desi?n team. ,. ,. ;.
"We appreciate the opportunity to provide our'professional services. Please. contact our office
t
there are any.qu.estions of comments concerning this•report or its reco nmendatioris.
t •..
R.espectful.ly.sub
'
EARTH SYS �L ST
.. ,�
CE 38234
:fi'
Craig.S 1:1111
E.XP. 3%.31/07
� �
.. • , . ;
. _ ,
CE 38234' `4
SERlcsh/reti-
Distribution: 6119 r. John Lane c/o A A Architects- r .
a
_ 1
1/RC File: 2:BD File _ ,
TABLE OF CONTENTS
}.
Page .
. EXECUTIVE SUMMARY
f
Section 1
INTRODUCTION... .......... ............................................................................
`
1.1
- Project Description.................................................•.•......1
1.2
Site Description ......................
1.3
Purpose and Scope of Work..............................................................................2
Section 2
METHODS OF INVEST.IGA.TION............................:...:..............................3
'
2.1
Field Exploration...........................................................:,..................................3
{
2.2
Laboratory Testing...........................................................:.................................3
•
Section 3
DISCUSSION.........................:.......................................................................4
•
^
�.1
Soil, Conditions.... ....•.•.••,,................... •.,........:4:...:...... . ........ .........••
a
i
.y
3.2
Groundwater
4
3.3
Geologic Setting..................................:.............................:.:........:.......:............4
3.4
Geologic Hazards ................... ........................ :......................_...... .............. ........
5
3.4.1 Seismic Hazards...............................................................
5
3.4.2 Secondary Hazards..............................................:........:...... ...........6
( '
.3.4.3 Site Acceleration and Seismic Coefficients............................................7
Section 4
CONCLUSIONS...
9
+
Section 5
RECOMMENDATIONS .................:.......:.........:............:...............:........:....10
.
i
SITE DEVELOPMENT ANTI) G.RADING......:...............:..............
5.1
..:........,.............1D
. Site Development —Grading
5.2
Excavations and Utilit; Trenches ...................... ... ............I........
l-1
5.3
.Slope Stability of Graded Slopes.............................................................
`
ST:RU.CTURES ..........................
}
5.4
Foundations .....................................................................................:.....:.........12
.X
y{ s
Slabs -on -Grade
z
5.6
Mitigation of Sail Corrosivity on Concrete.....................................................14
a
5.7
Seismic Design Criteria .................... I ....................... ........14
'.
't.
t; •
Section 6
LIMITATIONS AND ADDITIONAL SERVICES...:................................16'
- r
61
Uniformity of Conditions a:1d Limitations
6.2
Additional Services ....... .. ... : ............................ .................. ..17'
k
t
REFER
ENCES ... ............................. ...................... ..................:........ .. .1.8
APPENDIX
A
G
Figure l — Site Location Map
Figure 2 —.Boring Location :Map
Table 1 —.Fault Parameters :
Terms and Symbols used on Boring Logs
C-1
Soil Classification System
'.
Logs of $ornes
APPENDIX
B
i
Laboratory Test Results ,
r-ARTH SYSTEMS SOUTHWEST
i
EXECUTIVE SUiIMMARY
z Earth Systems Southwest has prepared this executive summary solely to provide a general
4 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 at 63-783 Via Palacio, L,ot 226 within -The Hideaway Country Club, in the
E City of .La Quinta; Riverside County, California. The proposed development will include a
7,000 -square foot one-story single-family residence. We understand that the proposed structure
will be of wood -frame and stucco construction supported with perimeter. wall foundations and
• concrete slabs-on-erade.
' 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, and concrete driveway and sidewalks 'placement. Remedial. site grading is
recommended to provide uniform support .for the foundations.
We consider the most significant geologic hazard to the project to be the potential %r moderate
to severe seismic shaking that is likely to occur during the design life of the proposed strictures.
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." The site islocated
in Seismic Zone 4 of the 2001 California Building Code (CBC). Structures should be desib ed
in 'accordance with the values and parameters given within the CBC. 'The seismic design
parameters are presented in the following table and. within the report.
FARTH SYSTEMS SOUTHWEST
Desygii item `;
Recommended Nirfiieter
r
Reference, See tion No.:.
•
Foundations
Allowable Bearing Pressure
,Continuous wall footings
Pad (Column) footings
1;500 Psf 5.4
2,000 sf
E Foundation Type
Spread Footing t 5.4
Bearine Materials
Engineered fill.
Allowable Passive Pressure
250 pcf 5.4
(-Allowable Coefficient of Friction
0.35 5.4
Soil; Ex ansion.Potential
Ve low JEl<20) 3.1
Geologic and Seismic Hazards
liquefaction. Potential Low to negligible ( 3.4.2
Si ni:ficant Fault and Magnitude San Andreas, M7•.7 ( 3.4.3; 5.7
Fault Ty e A. 3.4.3; 5.7
i
I Seismic Zone 4 14.3; 5.7
Soil Profile Tye _'SD;3.4.3; 5.7
Near -Source Distance 11.6 km 3.4.3; 5.7•
Near Source Factor, NA, :1.00 3.4.3; 5.7
Near Source Factor, Nv 1.13.3.4.3; 5.7
Slabs
Building Floor Slabs On engineered fill
5.5 -
Modulus of Suberade Reaction 1200 ci
5.5
-Existing Site Conditions
Existing Fill
Mass graded
Soil Corrosivity
low sulfates
low chlorides
5.6
Groundwater Depth
> 50 feet
3.2
'Estimated Fill and Cut
1 (i.ncludes over -excavation) _
IL
< 2 feet —cuts and fills
1.1
4 The •recommendations contained within this report are subject to the limitations presented in
t 4 . Section 6 of this report. We recommend that al.l individuals using this report read the limitations:
EARTH SYSTEMS SOLMHWEST:
y ?
E `.
rt; .
1
Apri1 14, 2005 1 File No.; 09902-02 .
05-04-747
GEOTECHNICAL ENG
Iti'E.ERING REPORT
PROPOSED SINGLE-FAMILY RESIDENCE
LOT 226 AT THE HIDEAWAY
i
53-783 VIA PALAC.10
LA QLINTA, CALIFORNIA
Section 1
INTRODUCTION
i
Ll Project Description
} This geotechnical engineering report has been prepared :for the proposed single-family residence .
to be located at 53-783 'Via Palacio, Lot 226 within The Hideaway Country Club, in the'City of
La Quinta, Riverside,County, California.
The. proposed custom home will be a single -story structure. We understand that the proposed
structure will be of wood -frame and stucco construction and will be supported by conventional _
shallow continuous or pad footings.
1
Site development will include clearing and grubbing of vegetation, site grading, building pad
preparation, underground utility installation, and concrete driveway and.* sidewalks placement.
Based on existing site topography and ground conditions, site grading is expected to consist of
minimal cuts and fills.
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 .
1.2 Site Description
The proposed custom home is to be constructed on the vacant lot on the west side of Via Palacio
within The Hideaway Country Club in the. City of La Quinta, California. The site location is
shown on Figure 1 in Appendix A.
The project site consists of an irregular-shaped lot that has been previously' rough graded in. t
conjunction with development of the tract. The proposed home site is relatively flat and level
with adjacent properties at an elevation of approximately 10 feet above .mean sea level. The site
is covered with a maintained brass lawn with a temporary underground irrigation system. The
site is bound by Via Palacio to the east, golf course to the west, a vacant lot to the south, and a
new home under construction to the north.
The histor-y of past use and development of the property was not investigated as part of our scope
of services. Some previous development of the site is possible. The site has been mass graded
r during construction .,of the tract. Buried remnants,. such as old foundations, slabs, or septic.
systems, that may have existed on the site were likely exposed and removed during grading, but
may still exist,
. i
There may be underground. utilities near and within the proposed building area. These utility
dines may include, but are not limited to, domestic water, electric; sewer, ,telephone, cable, and
Irrigation lines.
EARTH SYSTEMS SOUTHWEST �
ivy
April 14, 2005 2 File No.: 09902-02
05-04-747
1.3 Purpose and Scope of Work
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 three exploratory borings to depths ranging
from 14.5 to 31'.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 by ESSW for similar project in the vicinity.
> 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 geol.ogi.c and seismic hazards.
> Graphic and tabulated results of laboratory tests and field studies..
> Recommendations regarding:
Site development and gradnn criteria.
• Excavation conditions and. buried utility installations.
• Structure foundation type and design. - -
• Allowable foundation bearing capacity and expected total and differential settlements. r -
• Concrete slabs -on -grade.
• Mitigation of the potential corrosivity of site soils to concrete and steel reinforcement.
• Seismic design parameters.
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 fiirther
,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 SYSTE=MS SOUTI WEST `
r
April 1.4, 2005 3 Fileo.: 09902-02
05-04-747
Section 2
METHODS OF INIVESTIGATION .
2.l Field Exploration '
Three exploratory borings were drilled to depths -ranging from .14.5 to 31.5 feet below -the
existing ground surface to observe the soil profile and to obtain samples for laboratory testing.
The borings were drilled on March .17, 2005 using•8-inch outside diameter hollow -stem augers,
powered by a CME 55 truck -mounted drilling rig. The boring locations are shown on the boring
location. map, Figure 2, in Appendix A. The locations shown are approximate, established by
pacing and sighting from existing topographic features.
Samples were . obtained within the test borings using a Standard. Penetration (SPT) sampler
(ASTM D 1586) and a Modified California (MC) 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 1.586.. 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 loos 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
nt 0,e t b d b�tti y l 1 h h h b�
I F..rese approxima e . ou.n arjes .. leen soI . types, -.a t oug t c tra".; L Vn5 m.aS
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
:i 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:
i 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.
> Consolidation (Collapse Potential) to evaluate the compressibility and hydroconsolidation
(collapse) potential of the soil. .
Chemical. Analyses (Soluble Sulfates and Chlorides, pl-1, and Electrical Resistivity) to
evaluate the potential adverse effects of the soil on concrete and steel.
EARTH SYSTEMS SOUTHWEST
-
April 14, 2005 4 ..
File No.: 09902-02
05-04- 747
f Section 3
DISCUSSION
j 3.1 Soil Conditions
7 he Feld .exploration indicates that site soils consist generally of medium dense interbedded
fine-grained sand and silty sand (Unified Soils Classification System symbols of SP -SM and SM)
with occasional silt layers (ML). 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
i expansion (El. < 20) categoiy.in accordance with Table 18A -I-13 of the California Building Code.
In. and climatic regions, granular soils may have a potential to collapse upon wetting. Collapse
(hydro -consolidation) may occur.whein the soluble cements '(carbonates) in the soil matrix
dissolve; causing the soil to density from its loose configuration from deposition. Consolidation
testing indicates 1.2% collapse, upon inundation and collapse is therefore considered a s•-
�ht site
1 risk. The hydro -consolidation potential is commonly mitigated by re -compaction of a zone
beneath building pads.
The site lies within a recognized blow sand hazard area.. Fine particulate matter (1'Mio) can'.
create an air quality hazard. if dust is blowing. Watering the surface; planting gn-ass or
landscaping, or placing hardscape normally mitigates this hazard.
3.2. Groundwater
Free groundwater was not encountered in the borings during exploration. Historic' high
groundwater is believed to lie about 50 feet below original ground surface (and approximately
r 55 feet below existing grade) based on water well levels published in the vicinity of the site.
Groundwater should not be a. factor in design or construction at this site.
3.3 Geologic Setting
Regional Geoloov: 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
the Salton, "I'rough. 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.
y ,
` 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.
EARTH SYSTEMS SOUTHWEST
r
April 14, 2005 5 File No.: 09902-02
05-04-747
Local Geology: The project site is located in the southern portion of the Coachella Valley near
the eastern flanks of the Santa Rosa Mountains at an elevation of approximately 10 feet above
'+ mean sea level. " The project is located in an area that was once covered by the ancient Lake
Cahuilla. The sediments in this area of the valley generally consist o:f.fiine-grained sands with
interbedded clays . and silts :of aeol.ian (u=ind-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), slope instability,
flooding, ground subsidence, and erosion. A discussion follows on the specific hazards to this
" site.
3.4.1 Seismic I iazards
Seismic Sources: Several active faults or seismic zones lie within 62 miles (100 kilometers) of
the project site as shown on "Table. l in Appendix A. The primary seismic hazard to the site is
stro.ng ground shaking from earthquakes along the San Andreas and San Jacinto faults. The
Maximum Magnitude Earthquake (MmaX) listed is from published geologic information available
for each fault (Cao et al., CGS, 2003). The M.max corresponds to the maximum earthquake
believed to be tectonically possible..
Surface Fault Rupture: The project site does not lie within a currently .del ineated..State,.ot:
California, Alquist-Privlo Earthquake Fault Zone (14art, 1997)., Fell -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
L
previously established fault traces, future fault rupture could occur at other locations. "
Historic Seismicitv: Six historic seismic events (5.9 M or greater) have significantly affected the
Coachella. Valley in the last 100 years. They are as follows:
• Desert Hot Springs Earthquake — On December 4, 1948, a magnitude 6.5 'MI.. (6.01'0w)
earthquake occurred east of Desert I=lot. Springs. This event was strongly felt in the Palm
Springs 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
Andreas fault. This event was strongly felt'in the :Palm Springs area and caused structural
damage, as well as injuries.
• Joshua Tree Earthquake — On April 22, 1992, a magnitude 6.1 til, (6. I Mw) earthquake
occurred in the mountains 9 miles east of Desert Hot Springs. Structural damage and minor
injuries occurred in the :Palm Springs area as a result of this earthquake.
Ladders and .Big Bear Earthquakes. — Early on June 28, 1992, a magnitude 7.5 Ms (7.3Mtiv):
.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 (6AMw)
EARTI SYS'T'EMS SOUTHWEST
a
April 14, 2005 6 File No.: 09902-02
05-04-747
earthquake occurred near Big Bear Lake. No significant structural damage from these
earthquakes was reported in the Palm Springs area.
• Hector Mine Larthquake — On October 16, 1999, a magnitude 7.1Mvi 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, the California Geological Survey (CGS) and the
United States Geological Survey (USGS) completed the latest generation of probabilistic seismic
hazard maps. We have used these maps in our evaluation of the seismic risk at the site. The
Working Group of California Earthquake Probabilities (WGCEP, 1995) estimated a 22%
conditional probability that a magnitude 7 or greater earthquake may occur between 1994 and
2024 along the Coachella segment of the San Andreas fault.
The primary seismic risk at the site is a potential earthquake along the San :Andreas fault.
Geologists believe that the Sari 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 1690 AD, based on
dating by the USGS near .Indio (WGCEP, 1995). This segment has also ruptured on about 1020,
1300, and 1450 AD, with an average recurrence interval of about 220 ;fears. 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 low to negligible because the
depth of groundwater beneath the site exceeds 50 feet. No .free groundwater was encountered in
our exploratory borings. The project site lies within the Riverside County Liquefaction
Susceptibility Zone, but has a low potential because of the depth to groundwater.
Ground Subsidence: The potential for seismically induced ground subsidence is considered to be
slight 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.
EARTH SYSTEMS SOUTHWEST
`L
' April 14, 2005 7 . _F:ile No.: 09902-02.
.05-04-747
1 Slope Instability: The site is relatively flat. Therefore, potential hazards from slope instability,
1 landslides, or debris flows are considered negligible.
Flooding: The project site does not lie within a designated FEMA 100 -year flood plain. The
,project site may be in an area where sheet flooding and erosion could occur. If, significant .
changes are proposed for the site, appropriate project design, construction, and maintenance can
minimize the site sheet flooding potential.
is
33.4.3 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 I 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 Wary 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 to compare to the CBC Z factor and is generally
a poor indicator of "potential. structural damage during an' 'earthquak.e. Important factors
influencinu 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/I.)SGS seismic hazard maps. '
Estimate of PGA from 2002 CGS/USGS
Probabilistic Seismic Hazard Nlaps
— — -! .Equivalent Return
Risk Period (years)
PGA (9)'
L 10% exceedance in 50 years"' 475 W
0.50
Nates:
1. Based on a soft rock site;S,3;,;, and soil ampli�ication factor of 1.0 For Soil Profile Type So.
2001 CBG Seismic Coefficients: The California Building Code (CBC) seismic design criteria
are based on a Design Basis Earthquake (DBE) that has an earthquake ground motion with a
10% probability of occurrence in 50 years. The PGA estimate given above is provided for `
s information on the seismic risk. inherent in the CBC design. The seismic and site coefficients.
given in Chapter 16 of the 2001 California Building Code are provided in Section 5.7.of this
report and below.
EARTH SYSTEMS SOUTHW;,tST
is .._
April 14,2005
.8 File Na.: 09902-02
05-04-74.7
2001 CBC Seismic Coefficients for Chapter 1.6 Seismic Provisions "
Reference
Seismic Zone: 4 > Figure 16-2
Seismic Zone Factor, Z: 0:4 Table 16-1
Soil Profile Type:* ,So Table 16-J
k ` Seismic Source Type: A Table 16-G
Closest Distance to Known Seismic Source: 1. 1.6 km = 7.2 miles (San Andreas .fault)
Near Source Factor, Na: 1.00 Table 16-S
Near Sourcc :Factor, Nv: 1.13 Table 16-T
• Seismic Coefficient, Ca: 0.44 = 0.44Na Table 16-Q
Seismic Coefficient, Cv: 0.73 = 0.64Nv Table 16-R
Seismic Hazard Zones: The site lies within a liquefaction hazard area or zone established by the
2002 .Riverside Countv General Plan: however, the site is not located within a.recaonized
landslide or fault rupture hazard area or zone. Riverside County has not been napped by the.
California Seismic Hazard Mapping Act (Ca. PRC 2690 to. 2699).
EARTH SYSTEMS SOUTHWEST
April 14, 2005 9 File No.: 09902-02
r 05-04-747
Section 4
'
CONCLUSIONS
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:
x '
> , .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 Mitigation:
> 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
>r 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 project site is in seismic "Lone 4, is of soil profile Type So; and is about 11.6 km from
a Type A seismic source as defined in the California Building Code. A qualified
professional should design any permanent structure constructed on the site: The minimumA
seismic design should comply with the. 2001_ edition of the California Building Code.
Ground subsidence from seismic events or hydro -consolidation 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
r flooding; and. landslides; are considered low or negligible on this site.
i The soils within -the building and structural areas will require -moisture conditioning and
some compactive effort to fighten up the near surface soils. Soils can -be readily cut by
normal grading equipment.
EAR'Ct4 SYSTEMS SCLTIWEST
f
April. 14, 2005 10 File No.: 09902-02
05-04-747
Section 5
RECOMMENDATIO`S
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.
Cleariniz and Grubbing: At the start of site grading; existing vegetation and abandoned irrigation
pipes. 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 backfilled 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
(SCAQMD).
Building Pad. Preparation: We recommend that the pad be rolled with heavy equipment within
the building area. The applied compactive effort should extend at least 5 feet outside the
footprint of the proposed building and should include other portions of the site to be improved,
such as driveways, sidewalks, patios; etc. The bottoms of the foundation excavations should be
tested and probed to verify that the bearing soils have at least 90% relative compaction. It: soft- - -
areas are encountered, it will be necessary to compact the bearing soils as specified above. If a
pool is planned, then the bottom of the pool should be tested to verify that at least 2 feet meets at
least 90% relative compaction.
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.
Subgra.de 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. 1 foot below finished subgrades. 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.
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 sire 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 -
EARTH SYSTENTS SOUTHWEST
71r
April 14, 2005
File leo.: 09902-02
05-04-747
no greater than 8 inches in loose thickness and compacted to at least 90% relative compaction
(ASTIM 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. 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 Utilitv Trenches
Excavations should be made in accordance with Ca.IOSHA requirements. Our site exploration
and knowledge of the general area indicates there is .a potential .for -cavin, g 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.
Utilitv 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 confon-nance
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. Back ll
operations should be observed and tested to monitor compliance with these recommendations.
5.3 Slope Stability of Graded Slopes
Unprotected, permanent graded slopes should not be steeper than 3:1 (horizontal:vertical) to
reduce wind and rain erosion. Protected 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.
EARTH SYS TI NNIS SOUTH WEST
April 14, 2005 12 File No.: 09902-02
05-04-747
5.4 Foundations
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. 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 grade:
1500 psf for dead plus design live loads
_a
Allowable increases of 300 psf per each foot of additional footing width and 300 psf.for each
additional0.5 foot of footing depth maybe used up to a maximum value of 3000 psf.
> Isolated pad foundations. 2 x 2 foot minimum in Man and 18 inches below grade:
2000 ps;f for dead plus design live loads
Allowable increases of 200 psf per each foot of additional footing width and 400 psf for each
additional 0.5 foot of footing depth may be used up to a maximum value of 3000 psf.
A one-third (Yx) 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 1.1 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 (as specified in the California Building
Code) should be two No 4 steelreinforcing bars one placed near the top and one 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 1 inch, based on
footings founded on firm soils as recommended. Differential settlement between exterior and
interior bearing members should be less than Yz inch, expressed in a post -construction angular
distortion ratio ol: 1:480 or less.
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 250 pcf may also be used. These values include a factor of safety o:,: 1.5. Passive
resistance ani :frictional resistance may be used in combination if the friction coefficient is
reduced by one-third. A one-third (1/3) 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.
EARTFI SYSTEMS SOUTHWEST
April 14, 2005 13 File No.: 09902-02
05-04-747
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 (10 -mil thickness) should underlie the floor slabs. The
membrane should be covered with 2 inches o san 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.
The following minimum slab recommendations are intended to address geotechnical concerns
such as potential variations of the Subgrade and rare not to be construed as superseding any
structural design.
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 sub.2rade 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 4 inches thick (actual, not nominal). We
suggest that the concrete slabs be reinforced to resist 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. All joints should form approximately square
patterns to reduce the potential for randomly oriented contraction cracks. Contraction joints in
the slabs should be tooled at the time of the pour or saw cut ('h of slab depth) within 8 hours of
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 scaled 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 arid 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
EARTH SYSTEMS SOUTHWEST
April 14, 2005 14 File No,:. 0902-02 is
s 05-04-747
testing., Typically, for this type of construction and using 2500 -psi concrete, many of these
I quality control. procedures are not required. r.
1 5.6 - 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.',. The native soils were found to have a low sulfate ion concentration
l (145 'ppm) and a low chloride ion concentration (1.87 ppm). Sulfate ions can attack the
cementitious material' in concrete, causing }weakening of the cement matrix and eventual '-
�' r, deterioration by raveling. Chloride ions can cause corrosionof reinforcing steel. Th California
l Building Code does not require any special provisions for concrete For these low concentrations
astested.. Normalconcrete mixes may be used.
A minimum concrete cover of,three (3).inches should be -provided around steel reinforcing or
$ embedded components exposed to native soil or landscape water. .Additionally, the concrete
should be thoroughly vibrated during placement.
Electrical resistivity testing of the soil suggests that the site soils,Finaypresent a "very severe
potential for metal loss from electrochemical corrosion.processes. Corrosion protection'of steel
can be achieved by using epoxy corrosion inhibitors, asphalt coatings, cathodic protection; or
encapsulating with densely consolidated concrete.
t
The information provided above should be considered preliminary. These values can potentially'
a change based on several factors; such as importing, Soil from anotherjob. site and the- quality of
construction. water used during grading and subsequent landscape irrigation.
Earth Systems does not practise corrosion engineering. We recommend that a qualified
corrosion engineer evaluate the corrosion potential on rneta.l construction materials and concrete
at the site to provide mitigation of corrosive etffects, if further guidance is desired. -
5.7 Seismic Design Criteria.
t This situ 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 minimian seismic design should
comply with the 2001 edition of the California Building Code using the seismic coefficients
u given .in the table below.. ,
i
April 14; 2003 15 File No.: 09902-02
`. 03-04-747
i
2001 CBC Seismic Coefficients for Chapter 16 Seismic Provisions
Reference
Seismic Zone: 4 . Figure 16-2
Seismic Zone Factor, Z:, 0.4 Table 16-I. .
i Soil Profile Type: So Table 16-J
Seismic Source Type.: A Table] 6-U
-' Closest Distance to Known Seismic Source: 11.6 km = 7.2 miles (San Andreas fault)
Near Source Factor, Na: 1.00 Table 16-5
Near Source Factor, Nv: 1.13 Table 16-T
Seismic Coefficient, Ca: 0.440.44Na Table 16-Q
} Seismic Coefficient, Cv: 0.73 = 0.64Nv Table 16-R
,The CBC seismic coefficients are based on scientific knowledge, engineering judgment, and "
compromise. If further information on seismic design is .needed, a site-specific probabilistic
seismic analysis should be conducted.
"Che 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. 1n other words, damage is
allowed. • The CBC .lateral force requirements should be considered a minimum design: .'The
owner and the designer should 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
In
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.
r
EARTH SYSTEMS SOUTHWEST
April 14, 2005
16
Section 6
LIMITATIONS AND ADDITIONAL SERVICES
6.1 Uniformity of Conditions and Limitations
File No.: 09902-02
03-04-747
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
,S
significantly from those found at specific exploratory *locations. Var.iations in soil or
t 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 ofproperty 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 ow'ner'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
E
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
E: i.mpleme.nted in the design and specifications. If ESSW is not accorded the privilege of making
i yr
this recommended review, we can assume no responsibility for misinterpretation of our
F recommendations.
s
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 .
FAR i H SYSTEMS SOUTHWEST
F April 1.4, 2005 17 File No.: 09902-02
t 05-04-747
or toxic materials in the soil, surface water, groundwater, or air on, below, or adjacent to the
IV
lE
subject property.
y
1 ; : 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 final design and construction
phases to check compliance with these recommendations. Maintaining :ESS W 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
responsibilii)3 of Geotechnical Engineer of Record.
Construction monitoring and testing would be additional services provided by our firm. "rhe
3 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:
t Consultation during the final desibgn stages of the roJ
ect:
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, gradicig, and placement of engineered Li 11 .
as required b , CBC Sections 1701 and 3317 or local grading ordinances. =
• . Consultation as needed during construction.
-000-
Appendices as cited are attached and complete this report. T
i
EARTH SYSTEMS SOUTHWEST
s -
April 14, 2005 18 File No.': 09902-02
REFERENCES
Abrahamson, N. and Shedlock, K., editors; 1997, Ground motion attenuation relationships:
•°
Seism ological.Research Letters, v. 68, no. 1, January 1997 special issue, 256
P.
i American Concrete Institute (ACI), 1996, ACI Manual of Concrete Practice, Parts I through 5. ,
American Society of Civil Engineers (ASCE), 2003, Minimum Design Loads for Buildings and
Other Structures; ASCE 7-02
• California Geologic Survev (CGS), 1997, Guidelines for Evaluating and Mitigating Seismic
Hazards in California, Special Publication 117.
Cao, T. -Bryant, W.A., Rowhandel, B., Branum. D., and Wills, C.,'2003, 'nc Rcvised 2002
California 'Probabilistic Seismic Hazard Maps,, California Geologic Survey (CGS), June
2003:
-Envicom Corporation and the County of .Riverside Planning Department, 1976, Seismic Safety
r and Safety General Plan :Elements Technical. Report, County of Riverside..
Frankel, A.D., et al.; 2002, Documentation for the 2002 Update of the National Seismic Hazard
Maps, U SGS Open -File .Report 02-420.
.Hart, E.W., 1997, Fault -Rupture Hazard Zoncs in California:. California Division of.Mines and
Geology Special Publication.42_= -
x International Code -Council (ICC), 2002, California Building Code; 200.1 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., Lei.nkaemper,
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.
F .
Rogers, T.H., 1966, Geologic Map of California - Santa Ana Sheet, California Division of Mines
and. Geology Regional Map Series, scale 1:250,000.
Structural Engineers Association of California (SEAOC), 1996, .Recommended Lateral, Force
Requirements and Commentary.
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.
f` EARTH SYS T EMS SOUTHWEST
r i
APPENDIX .A
Figure 1 = Site Location Map
Figure 2 — Boring Location Map
a '.table I — Fault Parameters
Terms and Symbols used on .Boring Logs t` �
Soil. Classification Svstem
Logs of Borings
is
+.u3;��-�i*•..•�!: _. •c��ix¢h�,�'.c+..ti. �. •�v.�i l�:. ?�.t6...�...ssd.:w'c.....:._ a.,a���'w'��..��..3,r; ��.. 4�.x, ..a€x.'1:rii � �.; -� �.4
1 ,. - EARTH SY-S•I-"EMS SOUTHWEST - _ A •;
D
i
•'� y j t5� r � + } 1' J
17
' �. 11 �• � , � yam)
Wel!/
--- '3f ,,.AVENUE 52
till ifll `
C �Ire E i9.
73
Vol
V
�I'ICRI
C
AVENUE S
yy l 11
� }jrQ
4
! �a s z gp a rs
t��-
\tom `' ~�f \ i`,� • � ; j", ��1i�� 1 �`�.`�::...:: r. # r '
.........
''''���'�'''''' �� 6 y i t• /,� U \ t f ...._ =r.. __ l AV£NVE- 5660;
./
r r
kL
RM
ase I4ap: U.S. G.S, 7.5 Minute Quadrangle. la Quinta, Calif. (1959, photo -revised 1980)
••--•• Site Boundary
Scale: 1" _ .2,000'
0 2,000' 4,000'
i
1
i
i
Figure 1
Site Location
53-783 Via Palacio, Lot 226 at The Hideaway
La Quinta, Riverside County, California
Earth Systems
Southwest
04/14705 File No.: 09902-02
t
0
0
0
v
N
t•
M
0
0
0
c
N
h
M
O
0
04
N
t�
M
c
c
r:
e
C',
t•
M
567900
!: 6`15'57" if
568000 568100
56800
567900 568000 568100 568200
116"15'571Y
0 50 100 200 300 400 500
Feet
Figure 2
LEGEND Boring Location Map
53783 Via. Palacio
9 Boring Location Lot 226 at The HideaAay
La Quinta, Riverside County: California
Project area Earth Systems
o� Southwest
04/14/05 File too..: 09902-02
53-783 Via Palacio 09902-02
Table 1
Fault Parameters
oe tjete.rministic Gsumates of tvlean PeaK (ground Acceleration (11Gp
Maximum
Avg
Avg
Mean
Fault Name or
Distance
Fault
Mainitude
Slip
Return
Fault
Site
Seismic Lone
from Site
Type
Mmax
Rate
Period
Length
PGA
(mi)
(km)
(Mw)
(mmiyr)
(yrs)
(km)
{g)
Reference Notes: (1)
(2)
(3)
(4)
(2)
(2)
(2)
(5)
San Andreas - Southern
7.2
11.6
SS
A
7.1
24
220
199 ..
0.39
San Andreas - Mission Crk. Branch
8.7
14.0
SS
A
7.2
25
220 .
95
0.29
San Andreas - Banning Branch
8.7
14.0
SS
A
7.2
10
220
98
0.29
San Jacinto (blot Spgs - Buck Ridge)
15.0
24.2
SS
C
6.5
2
354
70
0.14
Blue Cut
17.2
27.7
SS
C
6.8
1
760
30
0.14
San Jacinto-Artza
19.2
30.8
SS
A
7.2
12
250
91
0.16
San Jacinto -Coyote Creek
20.1
32.3
SS
B
6.8
4
175
41
0.12
Burnt Mtn.
20.7
33,3
SS
B
6.5
0.6
5000
21
0.10
Eureka Peak
21.6
34,8
SS
B
6.4
0.6
5000
19
0.09
Morongo
31.9
51.3
SS
C
6.5
0.6
1170
23
0.07
San Jacinto - Borrego
32.0
51.5
SS
B
6.6
4
175
29
0.07
Pinto Mountain
33.5
53.9
SS
B
7.2
2,5
499
74
0.10
Emerson So. -Copper Mtn.
34.7
55.8
SS
B
7.0
0.6
5000
54
0.08
Landers
35.8
57.6
SS
B
7.3
0.6
5000
83
0.10
Pisgah -Bullion Mtn.-ivtesquite Lk'
36.2
58.3
SS
B
7.3
0.6
5000
89
0.09
Earthquake Valley
37.7
60.7
SS
B
6.5
2
351
20
0.06
San Jacinto -San Jacinto Valley
37.8
60.8
SS
B
. 6.9
12
- 83
43
0.07
Brawley Seismic Zone : .. .
38.8
62.4
SS-:-
-B
6.4
25
24
42
0.05
North Frontal Fault lone (last) .
"41.9
67.4
RV'
B
6.7
0.5
172 i
27
0.07
Elsinore -Julian
42.1
67.8
SS
. A
7.1
340
76
.0.07
Johnson Valley (Northern)
46.6
75.0
SS
B
6.7
0.6
5000
35
0.05
Elmore Ranch
46.7
75,2
SS
B
6.6
1
225
29
0.05
Elsinore -Temecula ..
47.2
76,0
SS
B .
6.8
5
240
43
0.05
Calico - hidalgo
48.2
117.6
SS
B
7.3
0.6
5000
95
0.07
Elsinore -Coyote Mountain
48.3
77.7
SS
B
6.8
4
625
`. 39
0.05
Superstition Mtn. (San Jacinto) _. 1
50.1
80.7
SS
B
6.6
5
500
24
0.05
Superstition Hills (San Jacinto) =
59:0.
82.1
. SS
B
6.6
4
250
23
0.04
Lemvood-Lockhart-Old Woman Sprgs
52.4
84.3
SS
B
7.5
0.6
5000
145
0.08
North Frontal Fault Zone (West) .
'52.8
84.9
RV
B
7.2
1
1314
50 .
0.08
.1•leicndele - S. Lockhardt •
60.0
96.6
SS
B
7.3
0.6
5000
97
0.06
San Jacinto -San Bernardino
60.9
98.0
SS
B
6.7
12
100
36
0.04
:'rotes:
1• Jennings (1994) and California Geologic Survey (CGS) (2003)
2. CGS (200.3), SS = Strike -Slip; RV =Reverse, DS = Dip Slip (normal), BT Blind Thrust
3. 1_001 CBC, where Type. A faults: IMmax >3 &. slip rate >5 mm%yr.& 'Pylae C faults: Mrnax <6.5 &. slip rate < 2 minlyr
i.
4, CGS (2003)
5. The estimates of the. mean Site PGA are based on the following attenuation. relationships:
Average oft (1) 1997 Soorc,.Joyner & Fumat; (2) 1997 Sadigh et al; (3) 1997 Campbell, (4) 1997 Abrahamson & Siiva
i.
] (mean plus sigma values are about 1.5 to 1.6 times higher)
Based on Site Coordinates: 33.660 N Latitude, 116.266 W Longtude and Site Soil •rypc D
t '
EARTH SYSTEMS SOUTHWEST
1
r.
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
1%" 3" `21AA An •n
.-_•, ••,.� 1a.1 "./V /-.VV V.If4 V.u($
SOIL GRAIN SIZE IN MILLIMETERS
0.002
RELATIVE DENSITY OF GRANULAR SOILS (GRAVELS, SANDS, AND NON -PLASTIC SILTS)
Very Loose
`N=0-4
- wv
Easily push a 1/2 -inch reinforcing rod by hand
BOULDERS
COBBLES
GRAVEL SAND
.
COARSE FINE COARSE MEDIUM FINE
N=11-30
RD=50-70
SILT CLAY
Dense
N=31-50
RD=70-90
Drive a 1/2 -inch reinforcing rod 1 foot with difficulty by a hammer
.-_•, ••,.� 1a.1 "./V /-.VV V.If4 V.u($
SOIL GRAIN SIZE IN MILLIMETERS
0.002
RELATIVE DENSITY OF GRANULAR SOILS (GRAVELS, SANDS, AND NON -PLASTIC SILTS)
Very Loose
`N=0-4
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 2I3) 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=2000-4000 psf
Dented slightly by finger pressure
Hard
N>30.
C>4000
Dented slightly by a pencil point or ftiiimbnail -
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%)
High
Above optimum moisture content (cohesive soil)
Saturated ........ .,Free
surface water .
after reaching the plastic limit.
LOG KEY SYMBOLS
PLASTICITY
DESCRIPTION
FIELD TEST
Bulk, Bag or Grab Sample
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.
Modified California Sampler
High
The thread can be rerolled several times
(3" outside diameter)
after reaching the plastic limit.
GROUNDWATER
LEVEL
No Recovery
Water Level (measured or after drilling)
-
Terms and Symbols used on Boring Logs
Water Level (during drilling)
Earth Systems
"�-
Southwest
MAJOR DIVISIONS
GRAPHIC
LETTER
TYPICAL DESCRIPTIONS
SYMBOL
SYMBOL
Well-graded gravels, gravel-sand
GW
mixtures, little or no fines
CLEAN'•'•'•'•'•'•'
GRAVELS�•'
GRAVEL AND
.•..•..• .•...•......,11P
Poorly-graded gravels, gravel-sand
GRAVELLY
�:r f;r: J:r:�:r:
mixtures. Little or no fines
SOILS
GM
Silty gravels, gravel-sand-silt
COARSE
More than 50% of
GRAVELS
mixtures
GRAINED SOILS
coarse fraction
WITH FINES
retained on No. 4
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)
SP
Poorly-graded sands, gravelly
More than 50% of
sands, little or no fines
material is larger
than No. 200
sieve size
SM
Silty sands, sand-silt mixtures
SAND WITH FINES
More than 50% of
(appreciable
coarse fraction
amount of fines)
Passing No. 4 sieve
SC
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
OL
Organic silts and organic silt
clays of low plasticity
SILTSAND
Inorganic silty, micaceous, or
CLAYS
MH
diatomaceous fine sand or
• -silty
soils
More than 50% of
material is smaller
LIQUID LIMIT
CH
Inorganic clays of high plasticity,
than No. 200
GREATER
fat clays
sieve size
THAN 50
Organic clays of medium to high
......
OH
plasticity, organic silts
.............
HIGHLY ORGANIC SOILS
J'J'J•yJ'yyJ'yyyy
yyyyyyyyyyyy
yyyyyyyyyyyy
PT
Peat, humus, swam soils with
p
yyyyyyyyyyyy
high organic contents
yyy"yyyyyyy
r r
VARIOUS SOILS AND MAN MADE MATERIALS
Fill Materials
MAN MADE MATERIALS
Asphalt and concrete
Soil Classification
System "
1 Earth Systems
j`
`� Southwest
Earth Systems
WE SouthwestPhone
Country Club Drive, Indio, CA 92203
Phone (760) 345-1588, Fax (760) 345-7315
fi
Boring NO: B-1
—Name:.
Drilling Date: March 17, 2005
Project53-783 Via Palacio, Lot 226, La Quinta, CA
Drilling Method: 8" Hollow Stem Auger
File Number: 09902-02
Drill Type: CME 55 W/Auto Hammer
Boring Location: See Figure 2
Logged By: Dirk Wiggins
v
Sample
Type
Penetration
�'
DCSCCIPt►On Of UI11ts Page 1 of 1
a
_
Resistance
_
E
A 3
_
Note: The stratification lines shown represent the
p
OJ
Y q
a
e
approximate boundary between soil and/or rock types Graphic Trend
q
zi a 0
Erni
(Blows/6")
rn
A
j
and the transition may be gradational. r Blow Count Dry Density
SM
SILTY SAND: moderate yellowish brown, medium
dense, damp, fine to medium grained
8,13,17
107
19
5
5,13,17
98
15
10
5,11,13
102
7
.'
SP -SM
SAND WITH SILT: pale yellowish brown, medium
dense, damp, fine to medium grained
15
dry to damp, trace of coarse grains
10,12,9
112
2
20
5,11,13
93
4
SM
SILTY SAND: pale yellowish brown, medium
dense, dryto damp, fine grained, lenses of sand with
silt
25
3,5,9
ML
91
24
SILT: pale yellowish brown to moderate olive
brown, medium dense, dry to damp, lenses of wet
silty clay
30
5,10,13
94
1
,
SP -SM
SAND WITH SILT: pale yellowish brown, medium
dense, dry, fine grained, reddish stains
Total Depth 31.5 feet
35
nn
No Groundwater Encountered
1
411
Earth Systems
^� Southwest 79-811B Country Club Drive, Indio, CA 92203
—20
- 25
— 30
- 35
L40 '
5;10,12
9,1 1,19
4,7,10
T.
SM
111
119
102
10
13
12
SILTY SAND: moderate brown, medium dense,
damp, fine to medium grained
dark yellowish brown, medium dense to dense, trace of
very fine grains
SP -SM ,.
SAND WITH SILT: pale yellowish brown, medium
dense, damp, fine to medium grained; reddish stains
3;5,8
91
5
418,12
93
5
Total Depth 21.5 feet
No Groundwater Encountered
L40 '
Earth Systems'
Southwest 79-811 B Country Club Drive, Indio, CA 92203
Borin No: B-3
Drilling Date: March 17, 2005
Project Name: 53-783 Via Palacio, Lot 226, La Quinta, CA
;Drilling Method: 8" Hollow Stem Auger
File Number: 09902-02
Drill Type: CME 55 W/Auto Hammer
Boring Location: See Figure 2
Logged By: Dirk Wiggins
Sample
W.
Type
Penetration
°?
Description of Units Page 1 of 1
a
w
Resistance
U
.�
q a .o
Note: The stratification lines shown represent the
A
a o
(Blows/6")
q
�v c
approximate boundary between soil and/or rock types Graphic Trend
N
q U
and the transition may be gradational. Blow Count Dry Density
2,5,10
Sm
99 7
SILTY SAND: moderate brown, medium dense,
damp, fine to medium grained
6,10,17
log it
5
3,6,10
ML
117 28
A
SILT: pale to moderate yellowish brown, medium
dense, damp, very fine grained, lenses of silty sand
10.
4,5,6
SM
93 6
SILTY SAND: pale yellowish brown, medium .
dense, dry to damp, fine grained, reddish stains
15,
Total Depth 14.5 feet
No Groundwater Encountered
20
25
30
r 35
Y_
— 40
a
1
t
• a �J.
' APPENDIX B
Laboratory Test Results
1
t
r
t
��"`c� .i � X'�� iy _ �F•�.F!S{.- • �f -tiy "S.
� �..2 ��F 1
•i5'- Y
I
EARTH SYSTEMS SOUTHWEST
File No.: 09902-02
April 14, 2005
UNIT DENSITIES AND MOISTURE CONTENT
ASTM D2937 & D2216
Job Name:
Lot 226,'Via Palacio, Hideaway, LQ, CA
w
USCS
Unit
Moisture
Sample
Depth Dry.
Content
Group
r
Location
(feet) Density (pcf)
(%)
Symbol
r B1
2.5 107 19
SM
BI
5 98 15
SM
BI
10 102 7
SP -SM
BI
15 112 2
SP -SM'
.>
-
BI
20 93 4
SM.
BI
25 91 24
ML
BI
30 .94 1
SP -SM
•
- B2
2.5 111 10
SM
B2
5 119 13
SM.
B2
10 102 12
SP -SM
B2
15 91 5
SP -SM
M�.
.
B2
20 93 5.
SP -SM
B3
0 99 . 7
SM
B3
#
3 109 11
SM M
J
'1
,..
B3
8 117 28
ML
B3
13 93 6
SM
EARTH SYSTEMS SOUTHWEST
•
File No.: 09902-02
April 14, 2005
..
.
PARTICLE SIZE ANALYSIS
ASTM D-422,
Job Name: Lot 226, Via Palacio, Hideaway, LQ, CA
Sample ID: B2 @ 1-4'
Description: Silty Sand, F
(SM)
Sieve
Percent
Size
Passing
1-1/2"
100
1"
100
1 3/411
100
1/2"
100
3/8"
100
#4
100
#8
100
#16
99 % Gravel:
0
#30
99 % Sand:
55
#50
97 % Silt:
34
#100
81 % Clay (3 micron):
11
#200,
45 (Clay content by short hydrometer method)
9
I�
{ 100
i
•
I
� '
I
i
i I I
I t
}'
70
i ;
i
i 1
I
j '
i I i
60
a50
{iL�If
I
III`'
I —
i l'i i
I�'iI I
IIIA,
:.
I I
I
L- ..�
iii
,
i� i.
I•.Li 1
30
. i
I'I
li I
I f
'III I I I
I
i.l
1
I I
20
.
j
i I
i 1
I
I
'
10
:;Iii
I
i I
I�
'II
i
,
I I' I j
� i•
_
i� i
i
- -
0-'-
100 10'
1 0.1
0.01 0.001
Particle Size ( mm)
EARTH SYSTEMS SOUTHWEST
File No.: 09902-02
April 14, 2005
CONSOLIDATION TEST ASTM D 2435 & D 5333
Lot 226, Via Palacio, Hideaway, LQ, CA Initial Dry Density: 89.2 pcf
B-3 @ 8 feet Initial Moisture, %: 27.7%
Silt (ML) Specific Gravity (assumed): 2.67
Ring Sample Initial Void Ratio: 0.868
Hydrocollapse: 1.2% @ 2.0 ksf
EARTH SYSTEMS SOUTHWEST
File No.: 09902-02 April 14, 2005
MAXIMUM DENSITY
UM MOISTURE ASTM D 1557-91 (Modified)
Job Name: Lot 226, Via Palacio, Hideaway, LQ, CA Procedure Used: A
Sample ID: 1 Preparation Method: Moist
Location: B2 @ 1-4' Rammer Type:. Mechanical
Description: Brown, Silty Sand, w/Silt Clumps, F
Lab Number: 05-0182
(SM -ML)
Sieve Size % Retained
Maximum Density: 120 p'cf 3/411 0.0
Optimum Moisture:
12.5% 3/8" 0.0
#4 0.0
140
135
130
110
105
100
J
. ............
< ----- Zero Air Voids Lines,
sg =2.65, 2,70, 2,75
.. ........ ..
.. . . ......
r
.-A
—7-
;-7
0 5 10 15 20 25 30 35
Moisture Content, percent
EARTH SYSTEMS SOUTHWEST
General Guidelines for Soil Corrosivity
Chemical Agent
Amount in Soil
Degree of Corr;sivity
File No.: 09902-02 r April 14,
2005
Lab Number: 05-0182
Sulfates
SOIL CHEMICAL ANALYSES
Moderate
. i •
Job Name: Lot 226, Via Palacio, Hideaway, LQ, CA
2000 - 20,000 mg/Kg (ppm) [0.2-2.0%]
Job No.: 09902-02
' Sample ID: B2
Very Severe
Sample Depth, feet: -14 DF
RL l
_ Sulfate, mg/Kg (ppm): " 145 1
0.5-0,
Chloride, mg/Kg (ppm): 187 1 "
0.20 r
pH, (pH Units): 7.80 1
0.41
Resistivity, (ohm -cm): 850 N/A
N/A
10,000+ ohm -cm
Low "
Conductivity, (µmhos -cm): 1
2.00
Note: Tests performed by Subcontract Laboratory:
Surabian-AG Laboratory DF: Dilution Factor
81-854 Sierra Avenue RL: Reporting Limit "
• '
Indio, California 92201 Tel: (776) 775-9700
General Guidelines for Soil Corrosivity
Chemical Agent
Amount in Soil
Degree of Corr;sivity
Soluble
- 0 -1000 mg/Kg (ppm) [ 0-A%]
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 m m) >2.0%
Very Severe
Resistivity s
1-1000 ohm -cm
'Very Severe
.1000-2000 ohm -cm
Severe
2000-10,000 ohm -cm
Moderate
10,000+ ohm -cm
Low "