04-5961 (CSCS) Geotechnical Investigation The Pavilionss.
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GEOTECHNICAL INVESTIGATION
THE PAVILION AT LA QUINTA COMMERCIAL COMPLEX
'NEC HIGHWAY 11 I AND ADAMS STREET
LA QUINTA, CALIFORNIA
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i -Prepared By-
Sladden Engineering
39-725 Garand Lane, Suite G
Palm Desert, California 92211
(760)772-3893
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Sladden Engineering
6782 Stanton Ave., Suite A. Buena Park, CA 90621 (714) 523-0952 Fax (714) 523-1369
39-725 Garand Ln., Suite G, Palm Desert, CA 92211 (760) 772-3893 Fax (760) 772-3895
February 17, 2004 Project No. 544-4010
04-02-139
Phomas Enterprises, Inc.
300 Village Green Circle
Smyrna, Georgia 30080
Attention: Mr. Kevin Case
Project: The Pavilion at' La Quinta Commercial Complex
NEC Highway 11 l and Adams Street
La Quinta, California
Subject: Geotechnical Investigation
Presented herewith is the report of our Geotechnical Investigation conducted at the site of the proposed
Pavilion at La Quinta commercial complex to be located on the northeast corner of Highway 111 and
Adams Street in the City of La Quinta, California. The investigation was performed in order to provide
recommendations for site preparation and to assist in foundation design for the proposed commercial
development.
This report presents the results of our field investigation and laboratory testing along with conclusions
and recommendations for foundation design and'site preparation. This report completes our original
scope of services as described in our proposal dated December 15, 2003.
We appreciate the opportunity to provide service to you on this project. If you have any questions
regarding this report, please contact the undersigned
Respectfully submitted,
SLADDEN ENGIN RING
Brett L. Anderso i
Principal Engineer ( =
SER/ma ✓rte'
Copies: 6,/ Thomas Enterprises, Inc.
Sladden Engineering
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GEOTECHNICAL INVESTIGATION
THE PAVILION AT LA QUINTA COMMERCIAL COMPLEX
NEC HIGHWAY 1 I I & ADAMS STREET
LA QUINTA, CALIFORNIA
February 17, 2004
TABLE OF CONTENTS
NTRODUCT[ON.....................:................................................................................................. I
SCOPEOF WORK ..................................................................................................................... 1
PROJECTDESCRIPTION......................................................................................................... I
SUBSURFACE CONDITIONS.................................................................................................. 2
CONCLUSIONS AND RECOMMENDATIONS...................................................................... 2
FoundationDesign................................................................................................................ 3
Settlements............................................................................................................................ 3
LateralDesign....................................................................................................................... 4
RetainingWalls.................................................................................................................... 4
ExpansiveSoils..................................................................................................................... 4
ConcreteSlabs-on-Grade...................................................................................................... 4
SolubleSulfates.................................................................................................................... 4
TentativePavement Design.................................................................................................. 5
Shrinkage and Subsidence.................................................................................................... 5
GeneralSite Grading............................................................................................................ 5
1. Clearing and Grubbing............................................................................................... 5
2. Preparation of Building Areas..................................................................................... 6
3. Preparation of Surfaces to Receive Compacted Fill ................................................... 6
4. Placement of Compacted Fill
5. Preparation of Slab and Pavement Areas................................................................... 6
6. Testing and Inspection............................................................................................... 6
GENERAL................................................................................................................................... 7
APPENDIX A - Site Plan and Boring Logs
Field Exploration
APPENDIX B - Laboratory Testing
Laboratory Test Results
APPENDIX C - 1997 UBC Seismic Design Criteria
Sladden Engineering
February 17, 2004 -1- Project No. 544-4010
04-02-139
INTRODUCTION
This report presents the results of our Geotechnical Investigation performed in order to provide
recommendations for site preparation and the design and construction of the foundations for the proposed
Pavilion at La Quinta commercial complex. The property is located on the northeast corner of Highway
I I1 and Adams Street in the City of La Quinta, California. The preliminary plans provided by Smith
Consulting Architects indicate that the proposed commercial complex will include several major retail
stores along with attached shop buildings and several detached retail pads. The associated site
improvements will include paved driveways and parking lots, underground utilities, and landscape areas.
SCOPE OF WORK
The purpose of our investigation was to determine certain engineering characteristics of the near surface
soils on the site in order to develop recommendations for foundation design and site preparation. Our
investigation included field exploration, laboratory testing, engineering analysis and the preparation of
his report. Evaluation of environmental issues or hazardous materials was not within the scope of
services provided. Our investigation was performed in accordance with contemporary geotechnical
engineering principles and practice. We make no other warranty, either express or implied.
PROJECT DESCRIPTION
T'he proposed project is located on the northeast corner of Highway 111 and Adams Street in the City of
La Quinta, California. The preliminary site plan indicates that the project will include a retail complex
occupying a total of 170,791 square feet and various associated site improvements. It is our assumption
that the proposed commercial buildings will be of relatively lightweight -reinforced masonry, steel -frame
or wood -frame construction. The associated site improvements will include paved driveways and parking
areas, landscape areas and various underground utilities.
The project site is presently' vacant and the ground surface is covered with sparse weeds. Prior to our
field investigation the site was rough graded including cuts and fills that resulted in the creation of
relatively level building pads. The previous rough grading is documented within our previous report
dated May 3, 2000. Highway 111 and Adams Street are paved adjacent to the site and there are existing
underground utilities along the streets. Commerce Way and Postal Road have also been constructed.
Based upon our previous experience with similar lightweight commercial/industrial structures, we expect
that isolated column loads will be less than 80 kips and wall loading will be less than 4.0 kips per linear
Foot. Future grading is expected to include minor cuts and fills to construct a level building pad and to
accommodate site drainage. This does not include removal and recompaction of the foundation bearing
soils within the building areas. If the anticipated foundation loading or site grading varies substantially
from that assumed, the recommendations included in this report should be reevaluated.
Sladden Engineering
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February 17, 2004 -2- Project No. 544-4010
04-02-139
SUBSURFACE CONDITIONS
The site is underlain primarily by a generally thin profile of artificial fill soils overlying native fine -
trained windblown sands with scattered sandy silt layers. Recovered ring samples and sampler
penetration resistance (as measured by blowcounts) indicate that the site soils are somewhat inconsistent
'i density but density appears to generally increase with depth. Relatively undisturbed samples indicate
dry density varying from 81 to 111 pcf.
The site soils were found to be generally dry throughout the depth of our borings but some of the silty
layers were wet. Moisture content varying from 1 to 42 percent was determined for the samples obtained
u ithin our borings.
Laboratory classification testing indicates that the near surface soils consist primarily of fine grained silty
sands. Expansion testing indicates that the surface soils are non -expansive and fall within the "very low"
expansion category in accordance with the Uniform Building Code classification system. The somewhat
inconsistent moisture conditions suggest that some of the near surface native soils underlying the site may
be susceptible to settlements'due to hydroconsolidation and compression.
Groundwater was not encountered in our borings and groundwater is expected to be in excess of 100 feet
below the existing ground surface. Groundwater should not be a factor in foundation design or
construction.
CONCLUSIONS AND RECOMMENDATIONS
Based upon our previous and recent field and laboratory investigations, it is our opinion that the proposed
Pavilion at La Quinta commercial complex is feasible from a soil mechanic's standpoint provided that the
recommendations included in this report are considered in building foundation design and site
preparation. Due to the somewhat inconsistent conditions of the near surface soils, remedial grading
including overexcavation and recompaction is recommended for the proposed building areas. We
recommend that remedial grading within the proposed building areas include overexcavation and
recompaction of the primary foundation bearing soils. Specific recommendations for site preparation are
presented in the site grading section of this report.
Groundwater was not encountered within our borings and groundwater is expected to be in excess of 100
feet below the existing ground surface. Due to the depth to groundwater, specific liquefaction analyses
were not performed. Based upon the depth to groundwater, the potential for liquefaction and the related
surficial affects of liquefaction impacting the site are considered negligible.
The site is located within an active seismic area of Southern California within approximately 8.7
kilometers of the San Andreas fault. Strong ground motion resulting from earthquake activity along the
nearby San Andreas or San Jacinto fault systems is likely to impact the site during the anticipated lifetime
of the structures. Structures should be designed by professionals familiar with the geologic and seismic
setting of the site. As a minimum, structure design should conform to Uniform Building Code (UBC)
requirements for Seismic Zone 4. Pertinent seismic design criteria as outlined in the 1997 UBC, is
summarized in Appendix C.
Sladden .Engineering
February 17, 2004 -3- Project No. 544-4010
04-02-139
Caving did occur within each of our exploratory borings and the surface soils will be susceptible to
caving within deeper excavations. All excavations should be constructed in accordance with the normal
CaIOSHA excavation criteria. On the basis of our observations of the materials encountered, we
anticipate that the subsoils will conform to those described by CalOSHA as Type C. Soil conditions
.hould be verified in the field by a "Competent person" employed by the Contractor. '
The surface soils encountered during our investigation were found to be non -expansive. Laboratory
testing indicated an Expansion Index of 0, which corresponds with the "very low" category in accordance
with UBC Standard 18-2.. If imported soils are to be used during grading, they should have an Expansion
Index of less than 20.
The following recommendations present more detailed design criteria that have been developed on the
basis of our field and laboratory investigation.
Foundation Design: The results of our investigation indicate that either conventional shallow
continuous footings or isolated pad footings that are supported upon properly compacted soils
may be expected to provide satisfactory support for the proposed structures. Recompaction
should be performed as described in the Site Grading Section of this report.
Footings should extend at least 12 inches beneath lowest adjacent grade for single -story
• structures. Isolated square *or rectangular footings at least 2 -feet square may be designed using an
allowable bearing value of 2000 pounds per square foot. Continuous footings at least 12 inches
wide may be designed using an allowable bearing value of 1800 pounds per square foot.
Allowable increases of 200 psf for each additional l -foot of width and 200 psf for each additional
6 -inches of depth may be utilized for larger footings. The maximum allowable bearing pressure
• should be 3000 psf. The allowable bearing pressures are for dead and frequently applied live
loads and may be increased by 113 to resist wind, seismic or other transient loading.
Because of the hydroconsolidation potential of some of the soils underlying the site, care should
be taken to see that bearing soils are not allowed to become saturated from the ponding of
rainwater or irrigation. Drainage from the building areas should be rapid and complete.
The recommendations made in the preceding paragraphs are based on the assumption that all
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footings will be supported upon properly compacted engineered fill soils. All gradingshall be
performed under the testing and inspection of the Soils Engineer or his representative. Prior to
the placement of concrete, we recommend that the footing excavations be inspected in order to
verify that they extend into compacted soil and are free of loose and disturbed materials.
Settlements: Settlements. may result from the anticipated foundation loads. These estimated
ultimate settlements are calculated to be a maximum of 1 -inch when using the recommended
bearing values. As a practical matter, differential settlements between footings can be assumed as
one-half of the total settlement.
Sladden Engineering
February ] 7. 2004 -4- Project No. 544-4010
04-02-139
Lateral Design: Resistance to lateral loads can be provided by a combination of friction acting
at the base of the slabs or foundations and passive earth pressure along the sides of the
foundations. A coefficient of friction of 0.45 between soil and concrete may be used with dead
load forces only. A passive earth pressure of 275 pounds per square foot, per foot of depth, may
be used for the sides of footings, which are poured against properly compacted native soils.
Passive earth pressure should be ignored within the upper 1 -foot except where confined (such as
beneath a floor slab). When used in combination, either the passive resistance or the coefficient
of friction should be reduced by one-third.
Retaining Walls:. Retaining walls may be required to accomplish the proposed construction.
Cantilever retaining walls may be designed using "active" pressures. Active pressures may be
estimated using an equivalent fluid weight of 35 pcf for native backfill soils with level free -
draining backfill conditions.
For walls that are restrained, "at rest" pressures should be utilized in design. At rest pressures
may be estimated using an equivalent fluid weight of 55 pcf for native backfill soils with level
free -draining backfill conditions.
Expansive Soils: Due to the prominence of non -expansive soils on the site, special expansive
soil design criteria should not be necessary for the design of foundations and concrete slabs -on -
grade. Final design criteria should be established by the Structural Engineer.
Concrete Slabs -on -Grade: All surfaces to receive concrete slabs -on -grade should be underlain
by recompacted soils as described in the Site Grading Section of this report. Where slabs are to
receive moisture sensitive floor coverings or where dampness of the floor slab is not desired, we
recommend the use of an appropriate vapor barrier. Vapor barriers should be protected by at least
two inches of sand in order to reduce the possibility of damage and to aid in obtaining uniform
concrete curing..
Reinforcement of slabs -on -grade in order to resist expansive soil pressures may not be required,
however reinforcement will have a beneficial effect in containing cracking due to concrete
shrinkage. Temperature and shrinkage related cracking should be anticipated in all concrete
slabs -on -grade. Slab reinforcement and the spacing of control joints should be determined by the
Structural Engineer.
Soluble Sulfates: The soluble sulfate concentrations of the surface soils were determined to be
approximately 555 parts per million (ppm). Soluble sulfate concentration will likely change as a
result of the recommended site grading. Soluble sulfate content should be determined after
grading and appropriate concrete mix designs should be selected in accordance with UBC Table
19-A-3.
Sladden Engineering
February 17, 2004 -5- Project No. 544-4010
04-02-139
Tentative Pavement Design: All paving should be underlain by a minimum compacted fill
thickness of 12 inches (excluding aggregate base). This may be performed as described in the
Site Grading Section of this report. R -Value testing performed during our previous investigation
resulted in an R -Value of 62. On this basis, a pavement section of 3.0 inches of asphalt on 4.0
inches of base material should be applicable for the design of the majority of the onsite pavement.
The appropriate pavement sections for off site improvements will be dependent upon traffic
indices determined by the City of La Quinta, California.
Aggregate base should conform to the requirements for Class 2 Aggregate base in Section 26 of
CalTrans Standard Specifications, January 1992. Asphaltic concrete should conform to Section
39 of the CalTrans Standard Specifications. The recommended sections should be provided with
a uniformly compacted subgrade and precise control of thickness and elevations during
placement.
Pavement and slab designs are tentative and should be confirmed at the completion of site
grading when the subgrade soils are in-place. This will include sampling and testing of the actual
subgrade soils and an analysis based upon the specific traffic information
Shrinkage and Subsidence: Volumetric shrinkage of the material that is excavated and replaced
as controlled compacted fill should be anticipated. We estimate that this shrinkage could vary
from 15 to 20 percent. Subsidence of the surfaces that are scarified and compacted should be
between 0.1 and 0.2 tenths of a foot. This will vary depending upon the type of equipment used,
the moisture content of the soil at the time of grading and the actual degree of compaction
attained.
These values for shrinkage and subsidence are exclusive of losses that will occur due to the
stripping of the organic material from the site, the removal -of deleterious materials and the
removal of debris, and other subsurface obstructions.
General Site Grading: All grading should be performed in accordance with the grading
ordinance of the City of La Quinta, California. The following recommendations have been
developed on the basis of our field investigation and laboratory testing:
1. Clearing and Grubbing: Proper clearing of any existing vegetation and debris will
be very important. All surfaces to receive compacted fill should be cleared of roots,
vegetation, debris, and other unsuitable materials which should be removed from the site.
Soils that are disturbed due to the removal of the surface vegetation, previous
improvements or artificial fill material should be replaced as controlled compacted fill
under the direction of the Soils Engineer.
Sladden Engineering
February 17, 2004 -6- Project No. 544-4010
04-02-139
2. Preparation of Building Areas: Within the building areas, removal and
recompaction of the primary foundation bearing soils is recommended. As a minimum,
removals within the building areas should extend to a depth of at least 3 feet below
existing grade or 3 feet below the bottom of the footings, whichever is deeper. The
exposed surface should be scarified, moisture conditioned and compacted so that a
minimum of 90% relative compaction is attained. Once deleterious materials are
removed, the native soils and artificial fill materials may be placed as controlled
compacted fill. Overexcavation should be observed by a representative of Sladden
Engineering and compaction should be verified by testing.' Overexcavation should
extend at least 5 feet laterally beyond the footings.
3. Preparation of Surfaces to Receive Compacted Fill: Other areas to receive
compacted fill should be brought to near optimum moisture content and compacted to a
minimum of 90% relative compaction.
4. Placement of Compacted Fill: Fill materials consisting of on-site soils or approved
imported granular soils, should be spread in thin lifts, and compacted at near optimum
moisture content to a minimum of 90% relative compaction. Tmported material shall
have an Expansion Index not exceeding 20. The contractor shall notify the Soils
Engineer at least 48 hours in advance of importing soils in order to provide sufficient
time for the evaluation of proposed import materials.
The contractor shall be responsible for delivering material to the site that complies with
the project specifications. Approval by the Soils Engineer will be based upon material
delivered to the site and not the preliminary evaluation of import sources.
Our observations of the material encountered during our investigation indicate that
compaction will be most readily obtained by means of heavy rubber -wheeled equipment
and/or vibratory compactors. At the time of our investigation, the subsoils were found to
be quite dry. A more uniform moisture content should be attained during recompaction
and fill placement. .
5. Preparation of Slab and Pavement Areas: All surfaces to receive asphalt concrete
pavement or concrete slabs -on -grade should be underlain by a minimum compacted fill
thickness of 12 inches. This may be accomplished by a combination of scarification and
recompaction of the surface soils. and placement .of the fill material as controlled
compacted fill. Compaction of the slab and pavement areas should be to a minimum of
90 percent relative compaction.
6. Testing and Inspection: During grading tests and observations should be performed
by the Soils Engineer or his representative in order to verify that the grading is being
performed in accordance with the project specifications. Field density testing shall be
performed in accordance with acceptable ASTM test methods. The minimum acceptable
degree of compaction should be 90 percent of the maximum dry density as obtained by
the ASTM D1557-91 test method. Where testing indicates insufficient density,
additional compactive effort shall be applied until retesting indicates satisfactory
compaction.
Sladden Engineering
February 17, 2004 -7- Project No. 54411010
04-02-139
GENERAL
the findings and recommendations presented in this report are based upon an interpolation of the soil
mnditions between the exploratory boring locations and extrapolation of these conditions throughout the
proposed building area. Should conditions encountered during grading appear different than those
indicated in this report, this office should be notified.
1his report is considered to be applicable for use by Thomas Enterprises, Inc. and its consultants for the
specific site and project described herein. The use of this report by other parties or for other projects is
not authorized. The recommendations of this report are contingent upon monitoring of the grading
operations by a representative of Sladden Engineering. All recommendations are considered to be
tentative pending our review'of the grading operations and additional testing, if indicated. If others are
employed to perform any soil testing, this office should be notified prior to such testing in order to
coordinate any required site visits by our representative and to assure indemnification of Sladden
Engineering.
Our investigation was conducted prior to the completion of plans for the project. We recommend that a
pre job conference be held on the site prior to the initiation of site grading. The purpose of this meeting
will be to assure a complete, understanding of the recommendations presented in this report as they apply
to the actual grading performed.
Sladden Engineering
8uraaa:rl�ug rrappnlS
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APPENDIX A
FIELD EXPLORATION
For our field investigation; 10 exploratory borings were excavated on January 16, 2004, using a truck
r.,ounted hollow stem auger rig (Mobile B53) in the approximate locations indicated on the site plan
included in this appendix. Continuous logs of the materials encountered were made on the site by a
representative of Sladden Engineering. Boring logs are included in this appendix.
Representative undisturbed samples were obtained within our borings by driving a thin-walled steel
lenetration sampler (California split spoon sampler) or a Standard Penetration Test'(SPT) sampler with a
140 pound hammer dropping approximately 30 inches (ASTM D1586). The number of blows required to
drive the samplers 18 inches was recorded (generally in 6 inch increments). Blowcounts are indicated on
the boring logs.
The California samplers are 3.0 inches in diameter, carrying brass sample rings having inner diameters of
2.5 inches. The standard penetration samplers are 2.0 inches in diameter with an inner diameter of 1.5
inches. Undisturbed samples were removed from the sampler and placed in moisture sealed containers in
order to preserve the natural soil 'moisture content. Bulk samples were obtained from the excavation
spoils and samples were then transported to our laboratory for further observations and testing. Samples
were then transported to our laboratory for further observations and testing.
Sladden Engineering
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Soil types;
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Job No.: 544-4010
REMARKS
8% passing #200
% passing 4200
% passing #200
7% passing #200
otal Depth = 21.S
to Bedrock
to Groundwater
Note: The stratification lines
represent the approximate
bounclarics between the soil types;
the transitions may be gradual.
ornia
Job No.: 544-4010
REMARKS
;sing #200
sing #200
ssing -:200
rising 4200
epth = 21.5'
Irock
iundwater
The stratification lines
;ent the approximate
caries between the soil types;
ansitions may be gradual.
The Pavilion at La Quinta
NWC Highway 111 and Adams Street / La Quinta, California
Date: 1-16-04
Borine No.5 Job No.: 544-4010
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DESCRIPTION
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REMARKS
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Sand: Grey brown,
SP
fisc grained
s
6/10/13
92
4
---
2% passing #200
is
9/23/33
"
No Recoverey
is
15/23/40
Silty Clay: Brown
CL
92
29
---
96% passing #200
20
-
Sand: Grey brown,
SP
-
27/39/50
tine grained
No Recoverey
Recovered Sample
Total Depth = 21.5'
® Disturbed Sample
No Bedrock
No Groundwater
25
30
35
40
~
45-
50
Note: The stratilication lines
55
represent the approximate
boundaries between the soil types;
the transitions may be gradual.
The Pavilion at La Quinta
NWC Highway 111 and Adams Street / La Quinta, California
Date: 1-16-04
orine No.7
Job No.: 544-4010
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DESCRIPTION
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REMARKS
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10
_
7/9/11
16/21/40
Sand: Grey brown,
fine grained
"
"
SP
"
"
98
96
3
2
•--
---
3% passing #200
2% passing 4200
is
16/23/20
Clayey Silt: Brown
ML
---
26
---
87% passing #200
20
_
21
30
35
40
as
so
21/32/36
14/24/30
23/26/26
26/24/24
30/50-6"
22/20/29
36/50-6"
Sand: Grey brown,
fine grained
" "
"
SP
"
-_-
---
---
-
4
3
3
6
2
2
I
.-.
---
---
---
---
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2 passing 9200
2% passing #200
3% passing 4200
I% passing #200
3/passing 4200
2% passing #200
1% passing 4200
ss
- Recovered Sample
m Standard Penetration
Sample
Note: The stratification lines
represent the approximate
boundaries between the soil types;
the transitions may be gradual.
Total Depth = 51.5'
No Bedrock
No Groundwater
Recovered Sample
No Bedrock
-
Disturbed Sample
No Groundwater
zs
30
ti
The Pavilion at La Quinta
NWC Highway 111 and Adams Street / La Quinta, California
Date: 1-
16-04 Borin
No.
10 Job Nn.: 544 -4Q -1-0—
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DESCRIPTION
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REMARKS
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-
-
-
Sand: Grey brown,
SP
-
fine grained
s
-
31/50-6"
I07
2
---
2% pass i ng #200
:14/16/18
10
Silty Clay; Brown with
CL
81
42
___
gg% passing #200
-
thin interbedded sand layers
is
-
Sand: Grey brown,
SP
_
17/30/30
fine rained
93
4
---
4% passing #200
"
Recovered Sample
= 16.5
Total Depth
No Bedrock
-
No Groundwater
zo
zs
_
30
y
35
40
45
-
50
i
-
Note: The straliticalian lines
ss
represent the approximate
boundaries between the soil types;
the transitions may be gradual.
Recovered Sample
= 16.5
No Bedrock
-
No Groundwater
zo
zs
_
30
y
35
40
45
-
50
i
-
Note: The straliticalian lines
ss
represent the approximate
boundaries between the soil types;
the transitions may be gradual.
d
APPENDIX B
Laboratory Testing
Laboratory Test Results
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Sladden Engineering
APPENDIX B
LABORATORY TESTING
P,epresentative bulk and relatively undisturbed soil samples were obtained in the field and returned to our
laboratory for additional observations and testing. Laboratory testing was generally performed in two
Chases. The first phase consisted of testing in order to determine the compaction of the existing natural
sail and the general engineering classifications of the soils underlying the site. This testing was
performed in order to estimate the engineering characteristics of the soil and to serve as a basis for
xlecting samples for the second phase of testing. The second phase consisted of soil mechanics testing.
`chis testing including consolidation, shear strength and expansion testing was performed in order to
provide a means of developing specific design recommendations based on the mechanical properties of
the soil.
CLASSIFICATION AND COMPACTION TESTING
unit Weight and Moisture Content Determinations: Each undisturbed sample was weighed and
measured in order to determine its unit weight. A small portion of each sample was then subjected to
testing in order to determine its moisture content. This was used in order to determine the dry density of
the soil in its natural condition. The results of this testing are shown on the Boring Logs.
Alaximum Density -Optimum Moisture Determinations: Representative soil types were selected for
maximum density determinations. This testing was performed in accordance with the ASTM Standard
D1557-91, Test Method A. The results of this testing are presented graphically in this appendix. The
maximum densities are compared to the field densities of the soil in order to determine the existing
relative compaction to the soil. This is shown on the Boring Logs, and is useful in estimating the strength'
and compressibility of the soil.
Classification Testing: Soil samples were selected for classification testing. This testing consists of
mechanical grain size analyses and Atterberg Limits determinations. These provide information for
developing classifications for the soil in accordance with the Unified Classification System. This
classification system categorizes the soil into groups having similar engineering characteristics. The
results of this testing are very useful in,detecting variations in the soils and in selecting samples for
further testing.
SOIL MECHANIC'S TESTING
Direct Shear Testing: Two bulk samples were selected for Direct Shear Testing. This testing measures
the shear strength of the soil under various normal pressures and is used in developing parameters for
foundation design and lateral design. Testing was performed using recompacted test specimens, which
were saturated prior to testing. Testing was performed using a strain controlled test apparatus with
normal pressures ranging from 800 to 2300 pounds per square foot.
Expansion Testing: These bulk samples were selected for Expansion testing. Expansion testing was
performed in accordance with the UBC Standard 18-2. This testing consists of remolding 4 -inch diameter
by 1 -inch thick test specimens to a moisture content and dry density corresponding to approximately 50
percent saturation. The samples are subjected to a surcharge of 144 pounds per square foot and allowed
to reach equilibrium. At that point the specimens are inundated with distilled water. The linear
expansion is then measured until complete.
Sladden Engineering
1997 UNIFORM BUILDING CODE SEISMIC DESIGN INFORMATION
'lhe International Conference of Building Officials 1997 Uniform Building Code contains substantial
revisions and additions to the earthquake engineering section in Chapter 16. New concepts contained in
Ile updated code that will likely be relevant to construction of the proposed structures are summarized
telow.
Ground shaking is expected to be the primary hazard most likely to affect the site, based upon proximity
b significant faults capable of generating large earthquakes. Major fault zones considered to be most
likely to create strong ground shaking at the site are listed below.
Fault Zone
Approximate Distance
From Site
Fault Type
1997 UBC
San Andreas
8.7 km
A
Sari Jacinto
32 km
A
Based on our field observations and understanding of local geologic conditions, the soil profile type
judged applicable to this site is SD, generally described as stiff or dense soil. The site is located within
UBC Seismic Zone 4. The following table presents additional coefficients and factors relevant to seismic
mitigation for new construction upon adoption of the 1997 code.
Sladden Engineering
Near -Source
Near -Source
Seismic
Seismic
Seismic
Acceleration
Velocity
Coefficient
Coefficient
Source
Factor, Na
Factor Nv
Ca
Cv
San Andreas
1.1
1.3
0.44 Na
0.64 N„
San Jacinto
1.0
1.0
0.44 Na
0.64 N„
Sladden Engineering
yw'r.-k i Y'r ;4
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r
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DETERMINISTIC ESTIN':P.TION OF
PEAK ACCE�EFATION FROMDT_GITIZED
FAULTS
JOB NUMBER": 544-4010
.
y
DATE: 02-06-2004
JOB NAME: NWC Highway li`_ & Adams Street
La Quinta, California
CALCULATION NAME: Test: Run Analysis
FAULT-DATA-FILE NAME,. CDMGFLTE.DAT
SITE COORDINATES:
SITE LATITUDE: 33.7094
SITE LONGITUDE: 116.284-4
SEARCH RADIUS: 100 M-4
f
ATTENUATION RELATION: 5) Boore et al. (1997) Horiz.
- SOIL (310)
UNCERTAINTY (M=Median, S=Sigma): M Number of
Sigmas: 0.0
DISTANCE MEASURE: cd_2drp
SCO,ND : 0
Basement Depth: 5.00 km Campbell SSR:
Campbell SHR:
COMPUTE PEAK HORIZONTAL ACCELERATION
e.
FAULT-DATA•,FILE USED: CDMGFLTE.DAT
MINIMUM DEPTH VALUE (km): 0.0
---------------
EQFAULT SUMMARY
---------------
DETERMINISTIC SITE PARAMETERS
-----------------------------
Page 1
I
(ESTIMATED MAX. EARTHQUAKE EVENT
I
APPROXIMATE I -------------------------------
ABBREVIATED I
DISTANCE I
MAXIMUM I
PEAK
IEST. SIi'E
FAULT NAME 1
mi
(km) (EARTHQUAKE(
SITE
IINTENSITY
'
I
MAG.(Mw) I
ACCEL. g
1MOD.MERC.
SAN ANDREAS - Coachella 1
5.4(
8.7)1
7.1 1
0.371
1 IX
SAN ANDREAS - Southern 1
5.4(
8.7)1
7.4 1
0.434
1 X
BURNT MTN. 1
'-7.1(
27.6)1
6.4 1
0.11.8
I VII
EUREKA PEAK 1
18.1(
29.1)1
6.4 1
0.113
1 VII
SAN ANDREAS - San Bernardino 1
18.5(
29.8)1
7.3 1
0.178
1 VIII
SAN JACINTO-ANZA 1
21.3(
34.3)1
7.2 1
0.152
1 VIII
SAN JACINTO-COYOTE CREEK 1
21.7(
34.9)1
6.8 1
0.122
1 VII
PINTO MOUNTAIN 1
29.9(
48.1)!
7.0 1
0.106
1 VII
EMERSON So. - COPPER MTN. 1
31.5(
50.7)1
6.9 1
0.096
1 VII
LANDERS 1
32.2(
51.9)1
7.3 1
0.117
1 VII
PISGAH-BULLION MTN.-MESQUITE LK 1
33.7(
54.2)1
7.1 1
0.102
1 VII
SAN JACINTO - BORREGO 1
35.6(
57.3)1
6.6 1
0.075
1 VII
SAP: JACINTO-SAN JACINTO VALLEY 1
36.4(
58.6)1
6.9 1
0.086
1 VII
NORTH FRONTAL, FAULT ZONE (East) 1
37.2.(
59.8)1
6.7 1
0.093
1 VII
EARTHQUAKE VALLEY 1
40.3(
64.8)1
6.5
0.065
1 VI
BRAWLEY SEISMIC ZONE 1
41.6(
66.9)1
6.4 1
0.060
1- VI
JOHNSON VALLEY (Northern) 1
43.1(
69.3)1
6.7 1
0.068
1 VI
ELSINORE-JULIAN 1
43.6(
70.2)1
7.1 1
0.083
1 VII
CALICO - HIDALGO 1
44.8(
72.1)1
7.1 1
0.082
1 VII
ELSINORE-TEMECULA 1
47.8(
76.9)1
6.8 1
0.066
1 VI
LENWOOD-LOCKHART-OLD WOMAN SPRGSI
48.8(
78.6)1
7.3 1
0.085
1 VIT
ELMORE RANCH 1
49.0(
78.8)1
6.6 1
0.059
1 VI
NORTH FRONTAL FAULT 'LONE (West) 1
49.2(
79.2)1
7.0 1
0.088
1 VII
ELSINORE-COYOTE MOUNTAIN 1
51.6(
83.1)1
6.8 1
0.062
1 VI
SUPERSTITION MTN. (San Jacinto) 1
53.7(
86.4)1
6.6 1
0.055
1 VI
SUPERSTITION HILLS (San Jacinto)1
54.6(
87.8)1
6.6 !
0.054
1 VI
HELENDALE - S. LOCKHARDT 1
56.7(
91.3)1
7.1 1
0.068
1 VI
SAN JACINTO-SAN BERNARDINO 1
58.7(
94.5)1
6.7 1
0.054
1 VI
ELSINORE-GLEN IVY (
61.3(
98.7)1
6.8 I
0.055
1 VI
CLEGHORN 1
66.1(
106.3)1
6.5 1
0.044
1 VI
:MPERIAL 1
68.7(
110.6)1
7.0 1
0.056
1 VI
L•AGUNA SALADA. 1
71.8(
115.6)1
7.0 1
0.054
1 VI
CUCAMONGA 1
73.8 1,
7.1.8.7) 1
7.0 1
0.064
1 VI
CHINO -CENTRAL AVE.- (Elsinore) 1
74.3(
119.5)1
6.7 1
0.054
I VI
NEWPORT-INGLEWOOD (Offshore) 1
76.1(
122.5)1
6.9 I
0.049
I VI
ROSE CANYON �' 1
76.2(
122.6)1
6.9 1
0.049
1 VI
WHITTIER 1
78.4(
126.1)1
6.6 1
0.045
1 VI
SAN ANDREAS - Mojave 1
82.8(
133.2)1
7.1 1
0.051
1 VI
SAN ANDREAS - 1857 Rupture 1
82.8(
133.2)1
7.8 1
0.073
1 VII
SAN JOSE (
85.5(
137.6)1
6.5 1
0.044
1 VI
-----------------------------
DETERM.-INTSTIC SITE PAR HETF'RS
-----------------------------
Pace 2 A
----------------------------------------------------------------------------------
I ESTIMATED MAX. EARTF?Q=UAKE EVENT
I APPRO`tIVATE---------
—
ABB.P.3;,'IATE D I D1•` 'Q--INCE MAXlHUV I PEAK JEST. SITE
=Af7L" NAMF. I rr,i (gym) i EARTHQUAKE I SITE I INTENS: T'
I MAC -.(Mw) I ACCEL. g IMOD. NERC
.
GRAVEL HILLS — HARPER LAKE 1 8$.2(.142.0;: 6.9 1 0.043 1 VT
STERRA MADRE 1 88.4( 142.3)1 7.0 1 0.056 1 VT
EL'YSIAN PARK THRUST 1 90.6( 14.5.£3) 6.7 1 0.047 i JI
CORONAD) RANK .1 91. 3(. 147.0) ! 7.4 I 0.055 V-
NE'WPORT—ING-LE6d11-110D (L.A.Sasir:) 1 94.6( 1.52.^) 6.9 I 0.041. V
C'LAMSHELT,—SAWPTT I 96.9 ( ,156.0) 1 6.5 1 C.040 I ��
COMPTON THRUS".' 1 97.3( —56.6,)1 6.8 1 0.046 Vi
PALOS VF RDFS 99.5 ( 160. 2) I 7 . ). 1 G-04-1 V-
* * * * Yr k• � i * * 'k a * = . + a a t a Y �v a a + * + % L a it * * a � i * a * + a.a * + a . 'Y i > a k T k k * a a * k * * � * x +' a i a /. + k � a r k k ! -
-END OF SEARC3— 48 FAULTS FOUND 'WITEIN THE SPECIFIED SEARCH RADIUS.
THE SAN ANDREAS - Coar_nel.l.a FAULT IS CLOSEST TO THE. SITE.
IT TS ABOUT 5.4 MILES (8:7 km) AWAY.
LARGEST MAXIM-UM—EARTHQUAKE SITE ACCELERATION: 0.4345 g
t
• r
ok
61
CALIFORNIA FAULT MAP
' NWC Highway I I I & Adams Street / La Quinta .
1100
1000
900
800
700
600
s
500
400
300
200
100 �Cy� , SITE
0
-100
-400 -300 -200 -100 0 100 200 300 400 500 600
X
STRIKE-SLIP FAULTS
5) Boore et al. (1997) Horiz. SOIL (31.0)
M=5 M=6 M=7 M=8
10 100
Distance [adistj (km)