13147 (CSCS) Geotechnical Engineering ReportTABLE OF CONTENTS
INTRODUCTION..........................................................................................................1
PURPOSEAND SCOPE OF WORK........................................................................1
SITEDESCRIPTION
.....................................................................................................2
FIELDEXPLORATION..................................................................................................2
LABORATORYTESTING..............................................................................................3
SOILCONDITIONS.....................................................................................................4
GROUNDWATER.........................................................................................................4
REGIONALGEOLOGY..............................................................................................4
LOCALGEOLOGY.....................................................................................................5
GEOLOGICHAZARDS...............................................................................................5
Primary.................................................................................................................5
Secondary.........................................................................................................6
Non-Seismic.......................................................................................................7
CONCLUSIONS AND DISCUSSIONS....................................................................a
SITEDEVELOPMENT..................................................................................................9
Site Development - Main Complex..........................................................9
Site Development - Satellite Buildings
....................................................11
Site Development - General.....................................................................12
Excavations......................................................................................................13
TrafficAreas.......................................................................................................13
UtilityTrenches..................................................................................................14
STRUCTURES..............................................................................................................14
Foundations.....................................................................................................14
Slabs-on-Grade.............................................................................................15
Settlement Considerations..........................................................................16
Frictional and Lateral Coefficients............................................................17
SlopeStability
..................................................................................................17
Expansion.........................................................................................................17
AdditionalServices........................................................................................17
LIMITATIONS AND UNIFORMITY OF CONDITIONS...........................................18
REFERENCES.............................................................................................................?D
APPENDIX A
Site and Vicinity Map
Logs of Borings
APPENDIX B
Summary of Test Results
Table 2
APPENDIX C
Standard Grading Specifications
BUENA ENGINERS, INC.
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INTgoDuCTION
This Geotechnical Engineering Report has been prepared for the
proposed commercial development to be located in La Quinta,
California.
A It is proposed to construct a large commercial complex on the
approximately sixty (40) acre site.
B. For the large structures throughout the main complex structural
considerations for column loads of up to 100 kips and a maximum
wall loading of 4.0 kips per linear foot were used as a basis for
recommendations as provided herein. These are estimated values
since we did not have foundation plans available at the time of
production of this report.
C. For the smaller satellite structures, structural considerations for building
column loads of up to 30 kips and a maximum wall loading of 2.0
kips per linear foot were used as a basis for recommendations
related to the construction of the residential buildings.
D. All loading is assumed to be dead plus reasonable live load.
E. If the actual loading exceeds the assumed loading the
recommendations provided herein will need to be reevaluated.
The purpose of our services was to evaluate the site soil conditions, and
to provide conclusions and recommendations relative to the site and
the proposed development. The scope of work includes the following:
A A general reconnaissance of the site.
1L AIL �1-
B. Shallow subsurface exploration by drilling limited to the hllUeilbsonls
building only.
C. Laboratory testing of selected soil samples obtained from the
exploratory borings drilled for this project.
D. Review of selected technical literature pertaining to the site.
E. Evaluation of field and laboratory data relative to soil conditions.
F. Engineering analysis of the data obtained from the exploration and
testing programs.
G. A summary of our findings and recommendations in written report.
BUENA ENGINERS, INC.
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Contained in This Report Are:
A Discussions on regional and local geologic and soil conditions.
B. Graphic and/or tabulated results of laboratory tests and field
studies.
C. Discussions and recommendations relative to allowable foundation
bearing capacity, recommendations for foundation design,
estimated total and differential settlements, lateral earth pressures
and site grading criteria.
Not Contained In This Report:
A Our scope of services did not include any environmental
assessment or investigation to determine the presence of
hazardous or toxic materials in the soil, surface water, groundwater
or air,'on, below or around this site.
The site of the proposed sixty (60) acre commercial development is
located on the north side of Highway 111 between Adams Street and
Washington Street in La Quinta, California.
A The Whitewater channel forms the north edge of the site.
B. The Washington Street forms the west edge of the site.
C. Highway 111 forms the south edge of the site.
D. The site is presently vacant with the exception of one existing
building along Highway 111 which is unoccupied. The remainder of
the site is covered with scattered desert brush, short grass, weeds
and debris.
E. It is obvious that previous grading has been performed on the site
during the construction of the adjacent storm channel and probably
prior to the construction of the existing building.
F. This investigation also includes a small two (2) acre site on the north
side of the Whitewater Channel at Adams Street.
Exploratory borings were drilled for observing the soil profile and
obtaining samples for further analysis.
A Twenty-three (23) borings were drilled for soil profiling and sampl?ng
to a maximum depth of fifty-one (51) feet below the existing ground
surface. Borings were drilled on February 20. March 2, 14 and 24, 1990,
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using an eight (6) inch diameter hollow -stem auger powered by ❑
CME 45-B drilling rig. The approximate boring locations as indicated
on the attached plan in Appendix A, were determined by pacing
and sighting from existing streets and topographic features. The
boring locations should be considered accurate only to the
degree implied by -the method used.
B. Samples were secured within the borings with a two and one-half
(2.5) inch diameter ring sampler (ASTM D 3550, shoe similar to ASTM D
1586). The samples were obtained by driving the sampler with a one
hundred forty (140) pound hammer, dropping thirty (30) inches. The
number of blows required to drive the sampler one foot was
recorded. Recovered soil samples were sealed in containers and
returned to the laboratory for further classification and testing.
_ _L..�..:.•.rrl from /"1 I�II'1(1C
C. Bulk disturbed sari-, 15— ai ; 11G ",�
developed during excavation of the test borings. The bulk samples
were secured for classification purposes and represent a mixture of
soils within the noted depths.
D. The final logs represent our interpretation of the contents of the field
logs, and the results of the laboratory observations and tests of the
field samples. The final logs are included in the appendix A of this
report. The stratification lines represent the approximate boundaries
between soil types although the transitions may be gradual.
After a visual and tactile classification in the field, samples were returned
to the laboratory, classifications were checked, and a testing program
was established.
A Samples were reviewed along with field logs to determine which
_.J.a t. p f, it -%,=r r,nnlV�P_H. Those chosen were considered as
WOUKArepresentative of soil which would be exposed and/or used in
grading and those deemed within building influence.
B. In -situ moisture content and unit dry weights for the core samples
were developed in accordance with ASTM D 2937.
C. The relative strength characteristics of the subsurface soils were
determined from the results of direct shear tests. Specimens were
placed in contact with water at least twenty-four (24) hours before
testing, and were then sheared under normal loads ranging from 0.5
to 2.0 kips per square foot in general accordance with ASTM D 3080.
D. Settlement and ors consolidation
tests
o t o performed) nas evaluated accordance from
wi h
the results o
ASTM 2435.
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E. Classification tests consisted of: Expansion Index (UBC Standard No.
29-2), Maximum Density -Optimum Moisture (ASTM D 1557) and
Hydrometer Analysis (California Test Method 203).
F. Refer to Appendix B for tabular and graphic representation of the
test results.
As determined by the borings, site soils were found to consist primarily of
fine silty sands. The boring logs in Appendix A contain a more detailed
description of the soils encountered.
A In -place densities indicate that the soils are of inconsistent density
but generally quite loose with ring densities indicating relative
compaction as low as fifty-five (55) percent of maximum density.
B. The upper four (4) to six (b) feet of soils encountered on the
northwest portion of the site were placed as fill materials during
previous grading.
C. The consolidation test data indicates that some of the site soils are
susceptible to large settlements due to hydroconsolidation and
loading. The majority of the highly collapsible soil was encountered
along the wash at depths of fifteen (15) to thirty (30) feet.
D. Clay and silt contents of the majority of the site soils exhibit low
plasticity. Expansion tests indicate soils, to be in the "very low"
expansion categories in accordance with Table 2 in Appendix B of
this report. Refer to section F of the structures section for specific
explanations and requirements dealing with expansive soil.
E. Soils should be readily cut by normal grading equipment.
Free groundwater was not encountered in any of the borings; however,
local information indicates the groundwater level is in excess of one
hundred (100) feet. Fluctuations in groundwater levels may occur due to
variations in rainfall, temperature and other factors.
The project site is located in the western Coachella Valley near the base
of the Santa Rosa Mountains, north of Indio Mountain. The Coachella
Valley is part of the tectonically active Salton Basin. This basin is a closed,
internally draining trough that has been filled with a complex series of
continental clastic materials during Pleistocene and Holocene time (Van
de Camp, 1973).
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The San Andreas rift zone dominates the geology of the Coachella
Valley. The Banning and Mission Creek faults, which are parts of the San
Andreas system are responsible for earthquakes recently felt in the
Coachella Valley. Other regional faults that have produced events felt in
the Coachella Valley are the San Jacinto, imperial and Elsinore faults
(see figures 1 & 2).
Based upon the historical and prehistorical record, the Coachella Valley
segment of the San Andreas fault system is likely to generate a
magnitude seven (7.0) or greater earthquake within the next fifty (50)
years, The potential for a magnitude seven (7•0) earthquake within the
next fifty (50) years is estimated by Seih (1985) as 'High" (50%-90%),
• _ • e
The proposed development is located on the east side of Washington
Street north of Highway 111. This area is south of the Whitewater River
Storm Channel. Lithologic units observed on site include Quaternary
❑eolian and alluvial deposited sediments and artificial fills. These units
are described as follows:
Gray brown, unconsolidated sand, silt and gravels. These sediments
have been deposited by fluvial or aeolian processes and are, found at
the base of the granitic rocks.
Generally the same as Qs found throughout the site but mainly in the
storm channel bank area.
The project site is located approximately five and five tenths (5.5) miles
9—..14. -......� mr4i Irc a chnwc the nroiect site in
southwest of the San hnareus iuull LVI y+.• v •'• •`---- - -
relation to the local geology.
A rim i mi H r
Primary seismic geologic hazards that may -affect any property in
the seismically active southern California region include ground
rupture and strong ground motion.
1. Fault Rupture:
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BUENA ENGINEERS, INC.
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mAP OF PP0JECT SITES
^ELAHPI 10 LOCAL GEOLOGY
SANTA A11A !TAP SHEET
FIr,UP1 3
BUENA ENGINEERS, INC.
DATE y 9-1a I FILE NO.a?-Zaf�'3-PI
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❑. The project site is not located in any Alquist-Priolo special
study zones. Nor are any faults mapped through or
adjacent to the project area. At the time of drilling no
surface expression of faulting was observed.
b. Fault rupture would most likely occur along previously
established traces. However, fault rupture may occur at
other locations not previously mapped.
2. Ground Shaking:
a. Strong ground motion is the seismic hazard most likely to
affect the site during the life of the intended structures.
Using methods developed by Seed and Idriss (1982) and
Ploessel & Slosson (1974), the following table was compiled
for anticipated acceierafions wi lici �a'r bG I:.�
during an earthquake at the project site.
TABLE 1
Estimated
Maximum Maximum Repeatable Approximate
Design Acceleration Acceleration Ground Distance to
Fnrth in Rock in " Accelerate Proiecf Site
San Andreas 7.5 .51g .48g Xg 5.7 mi
San Jacinto 6.5 .18g .159 .109 19.5 mi
' Richter Magnitude
Deep Cohesionless Soils
b. The project area is mapped in Ground Shaking Zone III C
as designated by the County of Riverside, California.
Ground Shaking Zones are based on distance from
causative faults and soil types.
_._ _��...,�...., of cnilc tvvn
C. Because of the thick shallI a ��u{ r ��r�� e% • •• -
thousand (2000 feet or more) under the site ground
shaking characteristics are expected to include
moderate amplification of all frequencies. Duration of
shaking could be from .(fifteen) 15 to thirty-six (36) seconds.
M . •
Secondary seismic geologic hazards that may affect the project
site area include subsidence, liquefaction, and ground lurching.
1. Subsidence, whether seismically related or not, is considered a
potential hazard in this area, Historic records report significant
episodes of subsidence in the La Quinta area due to seismic
forces and/or heavy rain fcli cnd flooding.
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2. Liquefaction is the loss of strength of saturated cohesioniess soils
generally from seismic shaking. In order for liquefaction to
occur, three principal conditions must be present. First, the soils
must have relative densities below seventy (70) percent;
second, the water table - perched or otherwise - must be within
the upper fifty (50) feet of soils; and third, the soils must have a
predominant grain size range between 0.5 mm and 0.01 mm.
Other criteria that identify susceptibility to liquefaction are a
uniformity coefficient between two (2) and ten (10) and ten (10)
percent passing between .01 mm and .25 mm, (Hunt,
Geotechnical Engineering Investigation Manual, McGraw-Hill
Book Co., 1984). When any of these conditions or criteria are
not satisfied, liquefaction is not considered a possibility.
3. No freewater was encountered in our exploratory borings
indicating that liquefaction is unlikely. Also, the project is not
located within the Riverside County Liquefaction Study Zone.
4. Ground lurching is generally associated with fault rupture and
liquefaction. Because of the distance of the project site to the
San Andreas fault system. The possibility of ground lurching
affecting the site is considered low.
5. The probability of other seismic hazards such as tsunamic and
seiches (waves oscillating in an inclosed area) impacting the
site is considered low.
C. Ngn-Seismic H
Other geologic hazards that could affect the project site include
landslides, flooding and erosion.
a. Evidence of past landsliding was not observed at the site. The
site is not at the base of any steep hills.
b. Flooding and erosion are always a consideration in arid
regions. On -site, the erosion rate is affected by sparse
vegetation and seasonal rains. The sites proximity to the
Whitewater storm channel may impact the planned
development. The storm channels sides are not protected
form erosion in this area.
c. The Coachella Valley averages four (4) inches of rain per year.
When large amounts of rain occur suddenly, the surface
alluvium becomes saturated and prevents further infiltration of
the rains. The result is surface runoff and sheet flow drainage on
slopes toward gullies and washes.
d. Generally, erosion in the desert can be reduced by minimizing
soil disturbances and diverting seasonal runoff from areas of
high potential erosion.
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v
Based on a review of selected technical literature and the site
investigation, it is our opinion that the site is suitable for the intended
development provided it is designed around the noted geologic
hazards. The following is ❑ summary of our conclusions and professional
opinions based on the data obtained.
A The primary geologic hazard relative to site development is severe
ground shaking from earthquakes originating on nearby faults. The
site is located in Southern California which is an active seismic area.
In our opinion, a major seismic event originating on either the San
Andreas or San Jacinto fault zones would be the most likely cause of
-:...._;ter ,"r%+ p&r,rtKr,, inkp r,r-tivity at the site within the estimated design
fife of the proposed development.
B. Subsidence, whether seismically related or not, is considered a
potential hazard. Adherence to the grading recommendations
contained in this report is necessary to limit differential settlements
and subsidence.
C. Areas of aeolian and alluvial soils may be susceptible to fluvial or
aeolian erosion processes. Preventative measures to minimize
seasonal flooding should be incorporated into site grading plans.
Disturbances of native ground cover should be minimized.
D. Due to the sites location directly adjacent to the Whitewater storm
channel and the unprotected condition of the storm channel walls,
erosion of said wails may impact site development. A licensed civil
engineer should be consulted regarding this concern.
E. Other hazards including liquefaction, lurching, seiching and tsunamis
are considered low to negligible.
1 .erg ...:F....,r. ..► ra-lcn, �---
F. It is our opinion that the site soils will Hof provlU tV u, a„W„ ��-�-J�--•-
suppdrt for the proposed structures without the recommended
sitework. Due to varying soil conditions, the recommended site
preparation will vary throughout the site. In general, we
recommend that structures be- supported by recompacted soil
mats to provide more uniform and firm bearing support. Additional
site work is recommended along the Whitewater Channel due to
the susceptibility to hydroconsolidation of the deeper soils.
G. The project site is in seismic Zone A as defined in Section 2312 (d) 2. of
the Uniform Building Code. It is recommended that any permanent
structure be designed according to the current additions of the
Uniform Building Code and Standards.
H. It is further recommended thet cny permcnent structure constructed
on the site be designed to accommodate expected repeatable
ground accelerations resulting from the predicted maximum
probable earthquake as stated in Table 1.
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I. Adherence to the following grading recommendations should limit
potential settlement problems due to seismic forces, heavy rainfall,
flooding and the weight of the intended structure.
J. It is recommended that Buena Engineers, Inc. be retained to
provide continuous Geotechnical Engineering services during site
development and grading, and foundation construction phases of
the work to observe compliance with the design concepts,
specifications and recommendations, and to allow design
changes in the event that subsurface conditions differ from those
anticipated prior to the start of construction.
K. Plans and specifications should be provided to Buena Engineers,
Inc. prior to grading. Plans should include the grading plans,
foundation plans, and foundation details. Preferably, structural loads
should be shown on the foundation plans.
As discussed the site soils are composed primarily of previously placed fill
material and native soils which were found to be quite dry with
inconsistent and generally low densities. The consolidation testing
indicates that much of the underlying native soil is susceptible to large
settlements due to the introduction of water and the additional loading
of structures. The magnitude and inconsistent nature of the potential
settlement along the Whitewater Channel is in our opinion unacceptable
for structural support. Limiting the potential settlement in this area is the
primary concern in site development. There are several alternatives for
site preparation of the northern portion of the site which should be
examined considering both cost and effectiveness.
A Site Dvl m t - Main QOmQIe
As previously mentioned, the site conditions vary greatly,
unfortunately the most severe conditions occur along the northern
edge of the site where the main shopping complex is proposed.
The following alternatives are presented for preparation of the
building areas along the Whitewater Channel.
1. Pile or drilled pier foundations extending through collapsible
soils into firm native soils could provide adequate support for
the proposed structures. The primary problem with the use of
pile or pier foundations is the potential settlement of auxiliary
structures such as retaining walls, sidewalks, etc. This problem
must be addressed. If specific building locations and loading
becomes available, pile or pier design can be provided.
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FJ
3.
S
5.
Complete removal of the collapsible material is perhaps the
most effective method of site preparation. However, with the
worst conditions encountered at depths of fifteen (15) to thirty
(30) feet, removal would involve extensive grading which could
be cost prohibitive.
The structure could be supported by normal spread footings
provided a recompacted soil mat of substantial thickness,
(approximated ten (1 0) feet) be constructed beneath the
footings. This option also involves extensive grading.
The use of large mat foundations is also a viable alternative
and would require significantly less recompaction, probably in
the range of five (5) feet thick. A primary consideration with mat
foundations is substantial cost associated with structural design
Perhaps the most economical solution is a combination of
recompaction, saturation and preconsolldation. Initially a
recompacted soil mat probably about five (5) feet thick should
be constructed. Water induction paints can then be drilled for
saturation of the deeper soils. Providing surcharge loads would
increase the effectiveness of the saturation and consolidation.
Adequate monitoring and follow-up testing is imperative in
determining preconsolidation effectiveness prior to
construction.
a. Water induction can be performed by drilling into the
problem layers and filling the borings with water for a
period of time in order to induce hydroconsolidation.
b. The induction borings will be necessary in areas where dry
collapsible layers were encountered, generally throughout
the northern portion of the site.
:....i....+�.•.n hnrir%nc will VQrV With
c. The depth and spUc::ing vi _c11
1%.A %w11W, , ,�,...... - - ,
the soils encountered and the time allotted. The necessary
spacing and depths will vary throughout the site.
d. The effectiveness of the water induction system should be
monitored during the watering process and adequate
moisture should be verified.
e. Because many of the site soils are very silty we
recommend that the building pads be graded prior to
water induction to avoid potential problems with
overexcavation.
6. The given aitematives are presence
specific information can be provided
configurations become available. The
architect and potential contractors
throughout site development.
d generally and more
when potential design
project civil engineer,
should be consulted
RIIPMA FNr.Mr-Pq I"
April 5, 1990 -11- B7-2083-P1
90-04-724
As previously discussed, the soil conditions encountered throughout
the southern portion of the site were not as severe as along the
wash and normal grading should be adequate for structure support.
Site grading should be visually checked by Buena Engineers, Inc.,
or their representative prior to placement of fill. Local variations in
soil conditions may warrant increasing the depth of recompaction
and/or excavation.
1. Prior to site grading any existing structures, stumps, roots,
foundations, pavements, leachfields, uncompacted fill and
trash piles, any abandoned underground utilities should be
removed from the proposed building and paving areas. The
top surface should be stripped of all organic growth and
noncomplying fill which along with other debris, should be
removed from the site.
2. Depressions resulting from these removals should have debris
and loose soil removed and be filled with suitable fill soils
adequately compacted. No compacted fill should be
placed unless the underlying soil has been observed by Buena
Engineers, Inc.
3. In order to help minimize potential settlement problems
associated with structures supported on a non -uniform thickness
of compacted fill, Buena Engineers, Inc. should be consulted
for site grading recommendations relative to backfilling large
and/or deep depressions resulting from removal under item 1
above. In general, all proposed construction should be
supported by a uniform thickness of compacted soils.
4. Due to widely varying soil conditions, the necessary grading will
vary from the southeast to the southwest portions of the site.
Due to the granular nature of the site soils throughout the
southeastern portion of the site, it is expected that compaction
may be obtained to a depth of three (3) to four (4) feet by
heavily watering and compacting from the surface. Because
the soils throughout the southwestern portion of the site are very
silty near the surface, removal and recompaction is
recommended.
5. Building areas throughout the southeastern portion of the site
should be moistened to at or above optimum moisture to a
depth of four (4) feet below original grade or the bottom of the
footings, whichever is deeper. The surface should be
compacted so that a minimum of ninety (90) percent of
maximum density is obtained to a depth of three (3) feet
below original grade or the bottom of the footings, whichever is
deeper if applicable, fill material should be placed in thin layers
at near optimum moisture and compacted to a minimum of
BUENA ENGINERS, INC.
April 5, 1990 -12- 137-2083-1'1
90-04-724
ninety (90) percent of maximum density. The intent is to have at
least three (3) feet of soil compacted to a minimum of ninety
(90) percent of maximum density compose the building pod
beneath the footings and to have an additional foot of
moisture penetration. Compaction is to be confirmed by
testing.
b. These grading requirements apply to building areas and at
least five (5) feet beyond building limits.
7. Auxiliary structures including freestanding or retaining walls shall
have the existing soils beneath the structure processed as per
items six (b), seven (7) and eight (8) above. The grading
requirements apply to three (3) feet beyond the face of the
walls. If plans for auxiliary structures and walls are, provided for
our review, these recoi i i 11 1tv,1u4011 , �s ; �a; --_- •- - -_ -
8. it is anticipated that during grading ❑ loss of approximately one
tenth (.1) of a foot due to stripping, and a shrinkage factor of
about ten (10) to twenty (20) percent for the upper five (5) feet
of soil, may be used for quantity calculations. This is based on
compactive effort needed to produce an average degree
of compaction of approximately ninety-three (93) to ninety-four
(94) percent and may vary depending on contractor methods.
Subsidence is estimated between two -tenths (2) to three -tenths
(.3) of a foot.
C, site Develop -nent_-_Q9_nQ_r_d
1. The following 'general' recommendations listed in this section
are in addition to those listed in Sections A and B above.
2. Any rocks larger d fan romlfght ill or(8) inches in back#i I mategaeatest dimension,
should be remoe
3. Import soil used to raise site grades should be equal t a or
better than on -site soil in strength, expansion,
compressibility characteristics. Import soil may be prequallfied
by Buena Engineers, Inc. Comments on the characteristics of
import will be giafter vhe en
Iis on the quantiiy for complete the
oject, either in -
place or in stockpiles of
project.
4. Areas around the structures should be graded so that drainage
is positive and away from the structures. Gutters and down
spouts should be
area. Watery shod as uld nay to convey water out of
ot be allowed to pond on
the foundation a
or near pavement sections.
5. Added moisture within previously compacted fill could result in a
number ofmoissture eactions nc ea e, the in place density at the surface of theupon
soilt
amount of in-
BUENA ENGINERS. INC.
April 5, 1990 -13- 137-2083-P1
90-04-724
situ moisture content and soil type. Although the soil could in
reality be expanding, collapsing, moving laterally due to the
phenomenon "creep', the result is usually movement and will
most likely manifest itself visually in structural slabs and street
areas as cracks, (horizontal, lateral and vertical displacement).
6. The apparent cure to the problem is to not introduce excess
moisture into fill material once in place, To help minimize
increased moisture into the fill material, site drainage and
landscape is critical. Site drainage should be in the form of roof
gutter, concrete brow ditcher, ribbon gutters and gutters, storm
drain and other drainage devices. Landscaping should be
such that water is not allowed to pond. Additionally, care
should be taken so as not to over water landscaped areas.
7. The Recommended Grading Specifications included in
Appendix C are general guidelines only and should not be
included directly into project specifications without first
incorporating the site specific recommendations contained in
the Site Development section of this report, Chapter 70 of the
Uniform Building Code contains specific considerations for
grading and is considered a part of these General Guidelines.
8. It is recommended that Buena Engineers, Inc., be retained to
provide soil engineering services during construction of the
grading, excavation, and foundation phases of the work. This is
to observe compliance with the design concepts,
specifications or recommendations and to allow design
changes in the event that subsurface conditions differ from
those anticipated prior to start of construction.
C. Ex v ti n
1. All excavations should be I
applicable regulations. Fror
knowledge of the general area,
construction problems involving
excavations (i,e. utilities, etc.)
encountered, lateral bracing or
be provided.
nade in accordance with
i our site exploration and
we feel there is a potential for
caving of relatively deep site
Where such situations are
appropriate cut slopes should
2. No surcharge loads should be allowed within a horizontal
distance measured from the top of the excavation slope,
equal- to the depth of the excavation.
D. Traffic Areas
1. Curbs and streets should be provided with two (2) feet of
subgrade compacted to ninety (90) percent of maximum
density.
2. On -site parking should be provided with two (2) feet of
subgrade compacted to ninety (90) percent of maximum
density.
BUFNA ENGINERS. INC.
April 5, 1990 -14- B7-2083-P1
90-04-724
E
3. Final preparation of subgrade will depend on paving section
designs.
4. Sidewalks should be provided with one (1) foot of subgrade
compacted to ninety (90) percent of maximum density.
Utility Trench
1. Backfill of utilities within road right-of-way should be placed in
strict conformance with the requirements of the governing
agency (Water District, Road Department, etc.).
2. Utility trench backfill within private property should be placed in
strict conformance with the provisions of this report relating to
minimum compaction standards. In general, service lines
extending inside of P1 VPV1I Y I I MApercent of maximum
compacted to a minimum of ninety (90) p
density.
3. Backfill operations should be observed and tested by Buena
Engineers, Inc., to monitor compliance with these
recommendations.
Based upon the results of this evaluation, it is our opinion that structure
foundation can be supported by compacted soils placed as
recommended above. The recommendations that follow are based
on "very low' expansion category soils.
r_VMMr*LrrV,7PM
It is anticipated that foundations will be placed on firm compacted
_:I_ .....r r^rY%cnA,=eq nipPwhere in this report. The
JVIIJ IG\rVIIsI�v..vv... �.--_----- - -
recommendations that follow are based on 'very low" expansion
category soils.
1. Table 2 gives specific recommendations for width, depth and
reinforcing. Other structural consideration may be more
stringent and would govern in any case. A minimum footing
depth of twelve (12) inches below lowest adjacent finish grade
for one (1) story structures and eighteen (18) inches for two (2)
story structures should be maintained.
2. Conventional Foundations:
Estimated bearing values are given below for foundations on
recompacted soils, assuming import fill (if required) to be equal
to or better than site soils:
BUENA ENGINERS, INC.
April 5, 1990 -15- 137-2083-P1
90-04-724
a. Continuous foundations of one (1) foot wide and twelve
(12) inches below grade:
i. 1400 psf for dead plus reasonable live loads.
ii. 1850 psf for wind and seismic considerations.
b. Isolated pad foundations 2' x 2' and bottomed twelve (12)
inches below grade:
i. 1600 psf for dead plus reasonable live loads.
H. 2150 psf for wind and seismic considerations.
3. Allowable increases of 200 psf per one (1) foot of additional
footing width and 300 psf for each additional six (6) inches of
footing depth may be used, The maximum allowable bearing
will be 2500 pcf. The allowable bearing values indicated have
been determined using a safety factor of three (3) and are
based upon anticipated maximum loads Indicated in the
introduction section of this report. If the indicated loading is
exceeded then the allowable bearing values and the
Grading Requirements must be reevaluated by the soils
engineer.
4. Although footing reinforcement may not be required per Table
2; one (1) number four (7-,r1L4) rebar at top and bottom of footings
should be considered to reduce the potential for cracking due
to temperature and shrinkage stresses and in order to span
surface imperfections. Other requirements that are more
stringent due to structural loads will govern.
5. Soils beneath footings and slabs should be premoistened prior
to placing concrete.
6. Lateral loads may be resisted by soil friction on floor slabs and
foundations and by passive resistance of the soils acting on
foundation stem walls. Lateral capacity is based partially on
the assumption that any required backfill adjacent tc
foundations and grade beams is properly compacted.
7. Foundation excavations should be visually observed by the soil
engineer during excavation and prior to placement of
reinforcing steel or concrete. local variations in conditions may
warrant deepening of footings.
8. Allowable bearing values are net (weight of footing and soil
surcharge may be neglected) and are applicable for dead
plus reasonable live loads.
1. Concrete slabs -on -grade should be supported by
compacted structural fill placed in accordance with
applicable sections of this report.
BUENA ENGINERS. INC.
April 5, 1990 -16- B7-2083-P1
90-04-724
2. In areas of moisture sensitive floor coverings, an appropriate
vapor barrier should be installed in order to minimize vapor
transmission from the subgrade soil to the slab. We would
suggest that the floor slabs be underlain by a four (4) inch thick
layer of gravel or by an impermeable membrane as a
capillary break. A suggested gradation for the gravel layer
would be as follows:
Sieve Size Percent Passing
3/4" 90-100
No. 4 0-10
No. 100 0-3
If a membrane is used, a low -slump concrete should be used
Thn Me_rr ik%rrina chniild be
i p t help protect it during
covered with two (2) inches of sand o
construction. The sand should be lighthly moistened just prior to
placing the concrete. Concrete slabs should be allowed to
cure thoroughly before placing moisture sensitive floor
covering.
3. Reinforcement of slab -on -grade is contingent upon the
structural engineers recommendations and the expansion
index of the supporting soil. Since the mixing of Hill soil with native
soil could change the expansion index, additional tests should
be conducted during rough grading to determine the
expansion index of the subgrade soil. Also, due to the
a high
temperature differential endemic .to desert areas, tg
concrete slabs on grade are susceptible to tension cracks. As
a minimum, we suggest that all interior concrete slabs -on -grade
be reinforced with 5" x b" / * 10 x # 10 welded wire fabric.
Additional reinforcement due to the expansion index of the site
soil should be provided as recommended in section F below.
Ar4A1+Inr%n1 nminfnrr.Pment may also be required by the structural
engineer.
4. it is recommended that the proposed perimeter slabs
(sidewalks, patios, etc.) be designed relatively independent of
foundation stems (free-floating) to help mitigate cracking due
to foundation settlement and/or expansion.
C. SQttlemgnt C:)nsideratiQn
The estimated settlement based on site preparation selected
can be estimated when specific information becomes
available.
BUENA ENGINERS, INC.
April 5,
1990
-17-
87-2083-P1
90-04-724
D. Frictional
and Lateral
Coefficients
1. Resistance to lateral loading may be provided by friction
acting on the base of foundations, a coefficient of friction of .49
may be used for dead load forces.
2. Passive resistance acting on the sides of foundation stems 300
pcf of equivalent fluid weight, may be included for resistance to
lateral loads. The value doe not include a factor of safety.
3. A one-third (1/3) increase in the quoted passive value may be
used for wind or seismic loads.
4. Passive resistance of soils against grade beams and the
frictional resistance between the floor slabs and the supporting
soils may be combined in determining the total lateral
resistance, however the friction factor should be reduced to .33
of dead load forces.
5. For retaining walls backfilled with compacted native soil, it is
recommended that an equivalent fluid pressure of thirty-five
(35) pcf be used for well drained level backfill conditions. The
pressure will increase significantly with sloping backfill.
Slope stability calculations were not performed for specific slopes. If
slopes exceed five (5) feet, engineering calculations should be
performed to substantiate the stability of slopes steeper than 2 to 1.
Fill slopes should be overfilled and trimmed back to competent
material.
The design of foundations should be based on the weighted
expansion index (UBC.Standard No. 29-2) of the soil. As stated in the
soil properties section, the expansion index of the majority of the on -
site soils are in the 'very low" (0-20) classification. However, during
site preparation, if the soil is thoroughly mixed and additional fill is
added, the expansion index may change. Therefore, the
expansion index should be evaluated after the site preparation has
been completed, and the final foundation design adjusted
accordingly.
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 Buena
Engineers, Inc., as the soil engineering firm from beginning to end of
the project will help assure continuity of services. Construction
BUENA ENGINERS. INC.
April 5, 1990 -18- B7-2083-P1
90-04-724
monitoring and testing would be additional services provided by
our firm. The costs of these services are not included in our present
fee arrangements. The recommended tests and observations
include, but are not necessarily limited to the following:
1. Consultation during the final design stages of the project.
2. Review of the building plans to observe that recommendations
of our report have been properly implemented into the design.
3. Observation and testing during site preparation, grading and
placement of engineered fill.
4. Consultation as required during construction.
MY,I kEN ■ 1.3 2 -P _■ o .► ON MN ► 1911111
The analysis and recommendations submitted in this report are based in
part upon the data obtained from the twenty-three (23) borings
performed on the site. The nature and extent of variations between the
borings may
become yef evident until
ce� necessary reevvariations
uate then
the
appear evident,
recommendations of this report.
Findings of this report are valid as of this date. However, changes in
conditions of a property can occur with passage of time whether they
be due to natural processes or works of man on this or adjacent
properties. In addition, changes in applicable or appropriate 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 eighteen (18) months.
+he o.,cn+ thnt nnv chances in the nature, design or location of the
ware planned, building the conclusions and recommendations
contained in this report shall not be considered valid unless the changes
are reviewed and conclusions of this report modified or verified in writing.
This report is issued with the understanding that it is the responsibility of the
owner, or of his representative, to insure that the information and
recommendations contained herein are called to the attention of the
-architect and engineers for the project and are incorporated into the
plans and specifications for the project. it is also the owners responsibility,
or his representative, to insure that the necessary steps are taken to see
that the general contractor and all subcontractors carry out such
recommendations in the field. it is further understood that the owner or his
representative is responsible for submittal of this report to the appropriate
governing agencies.
BUENA ENGINERS. INC.
April 5, 1990 -19- B7-2083-P1
90-04-724
Buena Engineers, Inc., has prepared this report for the exclusive use of
the client and authorized agents. This report has been prepared in
accordance with generally accepted soil and foundation engineering
practices. No other warranties, either expressed or implied, are made as
the professional advice provided under the terms of this agreement,
and included in the report.
It is recommended that Buena Engineers, Inc., be provided the
opportunity for a general review of final design and specifications in
order that earthwork and foundation recommendations may be
properly interpreted and implemented in the design and specifications,
If Buena Engineers, Inc., is not accorded the privilege of making this
recommended review, we can assume no responsibility for
misinterpretation of our recommendations.
Our scope of services did not include any environmental assessment or
investigation to determine the presence of hazardous or toxic materials
in the soil, surface water, groundwater or air, on, below or around this site.
Prior to purchase or development of this site, we suggest that an
environmental assessment be conducted which addresses
environmental concerns.
END OF TEXT
Appendices
BUENA ENGINERS, INC.
April 5, 1990 -20- B7-2083-P1
90-04-724
1. Envicom, Riverside County, 1976, Seismic Safety Element.
2. Krinitzsky, E.L., Chang, F.K., Magnitude -Related Earthquake Ground
Motions, Bulletin of the Association of Engineering Geologists Vol. XXV,
No. 4, 1988, Pgs. 399-423.
ble
3. Accelerations srfrom Earth akes n California CDMG Mapximum Shee23.
k
Accefe q
e Plnessel. M. R. and Slosson, J. E., "Repeatable High Ground
*77
Accelerations from Earthquakes', IY%4 V.,U111Vii Ina vwi.iyY, V
No. 9, P.gs. 195-199.
5. Seed, H. B. and Idriss, I. M., 1982, Ground Motions and Soil
Liquefaction During Earthquakes.
6. Seih, Kerry, 1965, "Earthquake Potentials Along The San Andreas
Fault', Minutes of The National Earthquake Prediction Evaluation
Council, March 29-30, 1985, USGS Open File Report 85-507.
BUENA ENGINERS, INC.
APPENDIX A
Site and Vicinity Map
Logs of Borings
BUENA ENGINERS, INC.
u
�o
Date: 02/28/90
L D .0 a O N E 3
O
S co
0
13
5 8
1❑ 6
15 23
20
25
30
35
40
45
5❑
Albertsons Market
Complex
Location: Per Plan BORING
NO. 2
a 3
>
>
DESCRIPTION o
0
E
^
U
File No. B7-2083-P1
REMARKS
Thin interbedded silt layers
throughout
A 1 : Grey brown very fine to SP
fine sand
86.8 1 1.2 1 82 1 Silt layer 1" thick
A2: Brown slightly clayey
silty very fine to fine
sand
Relatively undisturbed
ring sample
® No recovery
SM
®r�.��
Silt layer 3/4" thick
Total Depth = 16' No Free Water
No Bedrock
Note:
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
Albertsons Market Complex
Date: 02/28/90
Location: Per Plan
BORING NO. 4
File No. B7-2083-131
•
Q
3
>
> v
t m D m
DESCRIPTION
�_
o
o
m�
REMARKS
a E o 3
m a T U C
-
C
--
`- U
Cr.E
6
0
-
Closely interbedded B1 layers
- 45
A3: Brown clayey very
SM
93.7
1.5
79
throughout
-
silty very fine sand
5
24
10
15
A 1 : Grey brown very fine SIR
15
25
to fine sand 96.0 1.3 90
20
23
92.7 1.2 87
25
30
30
88.8 1.8 --
24
35
50111"
A 2: Brown slightly clayey SM
-
_
silty very fine to fine
40
sand
-50/9"
-
A4: Grey brown fine to Sp
-
medium sand with
45
trace coarse sand
33
_
Relatively undisturbed
_
ring sample
-
® No recovery
50
Closely interbedded B1 layers
7-15'
Scattered thin silty layers (A2)
15 - 2 5'
B1 layer 6" thick
Note:
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
Trace gravel
Total Depth = 46'
No Free Water
No Bedrock
Date: 03/02/90
t (D
E 0
3
m c
i. U
o
p -
U)
0
38
5
32
10
17
15
11
20
24
25
36
Albertsons Market Complex
Location: Per Plan BORING NO. 6 File No. B7-2083-P1
a 3 > > .2
DESCRIPTION o ^ 0 Q 8-
REMARKS
CO
d o o U
Al :Grey brown very fine 11 Sp 1 97.7 1.4 92 11 131 layer 2" thick
to fine sand Thin interbedded B1 layers
throughout
B1: Brown clayey silt 11 ML 9 76.8 5.3 - -
A2 Brown slightly clayey SM
silty very fine to fine
sand
Al : Grey brown very fine �� SP
to fine sand
30 A2: Brown slightly clayey SM
so
/ 1 0 " silty very fine to fine
sand
A 1 :Grey brown very fine SP
to fine sand
Relatively undisturbed
ring sample
® No recovery
92.1 1 1.5 1 87
Closely interbedded B1 layers
throughout
Thin interbedded 131 layers
throughout
Note:
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
Total Depth = 46'
No Free Water
No Bedrock
Albertsons Market Complex
Date: 03/02/90
Location: Per Plan
BORING NO. 7
File No. B7-2083-P1
r m
.0
m
H
3
DESCRIPTION
_
�
co
REMARKS
m c
i0
.
0
c
o
-- `=
0
A 1 :Grey brown very fine
SP
_
to fine sand
50/1 1
A2: Brown slightly clayey
SM
100.9
5.7
83
Interbedded B1 layers
-
silty very fine to fine
throughout
-
sand
5
30
95.2
0.5
87
Scattered thin B1 layers
•
A 1 :Grey brown very fine
Sp
throughout
to fine sand
10
7
A2: Brown slightly clayey
SM
_
silty very fine to fine
sand
15
9
67.9
5.0
---
-
Scattered thin A2 layers -
_
throughout
20
22
B1: Brown clayey silt
ML
100.9
5.7
83
25
32
100.9
5.7
83
797M_
A2: Brown slightly clayey
SM
30
36
silty very fine to fine
97.0
0.7
89
Closely interbedded B1 layers
-
sand
_
B1: Brown clayey silt
ML
35
-
45
Scattered A4 layers
-
Al : Grey brown very fine
SP
Note:
to fine sand
40
The stratification .lines
-
50/9"
represent the approximate
-
boundaries between the
-
soil types; the transitions
-
may be gradual.
45
50/9"
-
- Relatively undisturbed
Total Depth = 46'
ring sample
No Free Water
® No recovery
No Bedrock
50
Albertsons
Market Complex
Date: 03/02/90
Location: Per Plan
BORING NO. 8
7
File No. 137-2083-131
77
---------
�
CL
0
>
-=
DESCRIPTION
DESCRI
0
0 0 a0
REMARKS
CL C
0)
13 z-
E
:s-
CD
L)
3:
0
.0
0
Cn
— C
CL
2 cc E
01
-0-0 *0
Fill material
0
A3: Brown clayey very
sm
silty very fine sand
25
95.6
8.0 80
A 2:
SM
5
2
30
A 1 Grey brown very fine
SP
to fine sand
10
10
A2: Brown slightly clayey
SM
1.3
B1 layer 6" thick
WILY VU1Y 11110 &W 11-1w
L;ioseiy interbedded 81 layers
sand
throughout
15
13
88.2
2.0 76
20
Al : Grey brown very fine
Grey
SP
82.1
1.4 :77
A3 layers throughout
12
es
to fine
--
Thin interbedded B1 layers
25
A3: Brown clayey very
sm
throughout
13
silty very fine sand
30
25
Scattered A3 layers throughout
A I :Grey brown very fine
SP
to fine sand
35
50/9"
Total Depth = 41'
No Free Water
C11: Brown slightly sandy
CIL
No Bedrock
40
silty clay
g1.8
14.9
50/9,
Relatively undisturbed
ring sample
Note:
4 5
The stratification lines
No recovery
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
Date: 03/14/90
tm .0 m 3
o c
m c U
0
10
5 7
to
15 18
20
25
30
35
40
45
50
Albertsons Market Complex
Location: Per Plan BORING NO. 10
(D > > .Q
DESCRIPTION o 0 E
cc
j a o o 0
A 1 : Grey brown very fine to
fine sand
® No recovery
Ii
File No. B7-2083-P1
REMARKS
4rattared A2 layers
Total Depth = 16'
No Free Water
No Bedrock
Note:
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
Albertsons Market Complex
Date: 02/26/90
Location: Per Plan
BORING NO. 12
File No. B7-2083-P1
n
m
3
m c
•°
m
o
o
o
DESCRIPTION
�
o
0
Z
REMARKS
o�
to U
1
(0°°a
�°
Oil
D
o
o
0
A3: Brown clayey very
sM
Thin B1 layers throughout
_
-
silty very fine sand
-'
2.9
43
5
B1: Brown clayey silt
ML
89.0
5.0
75
23
1 0
91
Al : Grev brown very fine
Sp
94.7
1.0
89
-
to fine sand
15
27
89.9
1.4
85
-
Thin interbedded Bt layers
throughout
20
50/12"
-
A2: Brown slightly clayey
sM
silty very fine to fine
_
sand
25
50/6"
30
50/6'
_
- Relatively undisturbed
Twinl 1'1nnfF_ 'i1
I VtQ1 `'"r"'
-
ring sample
No Free Water
_
No Bedrock
35
-
No recovery
40
Note:
The stratification Jines
45
represent the approximate
_
boundaries between the
soil types; the transitions
_
may be gradual.
50
Albertsons Market Complex
Date: 02/28/90
Location: Per Plan
BORING NO. 14
File No. B7-2083-P1
a
3
>
> o
m
E
o
o
DESCRIPTION
o
0
Z O
REMARKS
p .°—�
cn
U
M
U)
a
*0
- °
U
�
o
o
0
B 1 : Brown clayey silt
ML
50/8"
98.0
4.4
82
Thin interbedded B1 layers
5
23
94 1
1 9
81
throughout
-
A2: Brown slightly clayey
SM
-
silty very fine to fine
-
sand
n
e1 d
1 1
7Q
Interbedded B1 layers 12 - 17'
1.5
23
95.3
0.9
90
-
A 1 :Grey brown very fine
SP
-
to fine sand
20
38
-
Scattered A2 layers 20 - 25'
25
30
Relatively undisturbed
Total Depth = 26'
ring sample
No Free Water
No Bedrock
30
-
� Aln rnrnvnry
35
40
Note:
45
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
50
Albertsons Market Complex
Date: 03/22/90
Location: Per Plan
BORING NO. 16
File No. B7-2083-P1
a
3
m
E o
3
DESCRIPTION
o
0 C
REMARKS
a
m C
Q—
>. U
cn
C
0
'C U o
a o
o 0
o U
0
A2: Brown slightly clayey
SM
silty very fine to fine
-
5 0/ 1 0
sand
112.8 9.3
97
B1 layers throughout
6
A 1 : Grey brown very fine
SP
-
31
to fine sand
B 1 : Brown clayey silt
ML
_
I n
87.2 2.6
82
Closely interbedded B1-
-
layers 10 - 17'
Al : Grey brown very fine
SP
1 5
to fine sand
86.2 2.4
80
17
20
33
Scattered thin B1 layers
A3: Brown clayey very
SM
"
silty very fine sand
25
50/10"
-
A 4 : Grey brown fine to
SP
medium sand with
trace coarse sand
30
rL4
25
35
Scattered thin clay layers
50/1 1 •
throughout
-
A 1 :Grey brown very fine
SP
Note:
-
40
to fine sand
The stratification lines
-
35
represent the approximate
boundaries between the
_
soil types; the transitions
_
may be gradual.
45
50
- Relatively undisturbed
Total Depth = 46'
ring sample
No Free Water
® No recovery
No Bedrock
50
Date: 03/22/90
t m 0 m N
a E
0 0
(D c N U
0
23
5 28
in
15 18
20 23
25 50
30 20
35
40
45
50
Albertsons
Market Complex
Location: Per Plan
BORING NO. 18
ma
m m c
> .0
DESCRIPTION
o 0 E
O
U)
_0
U O
0-0 U
D a ;
B 1 : Brown clayey silt
ML
A2: Brown slightly clayey SM
silty very fine to fine
sand 11
File No. B7-2083-P1
REMARKS
Thin interbedded silt layers
throughout
80.5 1.4 i 76 A2 layer 6" thick
A 1 : Grey -brown veryfine-SP -Thin A2 layers throughout --
to fine sand
B1: Brown clayey silt ML
75.7 7.1 - - -
A2: Brown slightly clayey 1I SM
silty very fine to fine
A4: Grey brown fine to
medium sand with
trace coarse sand
Relatively undisturbed
ring sample
No recovery
Thin interbedded silt layers
throughout
Total Depin - 31'
No Free Water
No Bedrock
Note:
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
Date: 03/23/90
t m 0 m N
O
p U) U
0
25
5 i' '_ 25
�n
1 J V
15 15
20 16
25 30
30 50/1 1 "
35
40
45
50
Albertsons Market Complex
Location: Per Plan BORING NO. 20 File No. B7-2083-P1
(D > > .Q
DESCRIPTION o ^ 0 C REMARKS
n a o o U
A 1 : Grey brown very fine SP
to fine sand11 Widely scattered thin silt
lavers 2 - 4'
98.7 2.4 85
A2: Brown slightly clayey SM Thin interbedded B1 layers
silty very fine to fine throughout
sand
B1 layer 2" thick
B1: Brown clayey silt 11 ML
A 1 : Grey brown very fine �! SP
to fine sand
Relatively undisturbed
ring sample
No recovery
61.0 1 11.71 ---
88.4 12.9 , 83 lj B1 layer 3" thick
Scattered thin silt layers
20 - 30'
i otai Depin - 31'
No Free Water
No Bedrock
Note:
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
Date: 03/23/90
r m M m
3
0
29
5 26
10 32
15 18
20 18
25 50
30 50/11
35
40
45
50
Albertsons Market Complex
Location: Per Plan BORING NO. 22
c
a 3 > > .o
DESCRIPTION o 0 -6 E
N :3 CL o o U
A2: Brown slightly clayey
silty very fine to fine
sand
A 1 : Grey brown very fine
to fine sand
B1: Brown clayey silt
A 2: Brown slightly clayey
silty very fine to fine
sand
- Relatively undisturbed
ring sample
No recovery
File No. B7-2083-P1
REMARKS
SP 1 99.0 1 2.8 1 93 11 Thin silt layer
ML
86.1 1 6.6 1 - - - 11 Thin Al layers
67.9 1 7.9 1 - - - 11 A3 layer 2' thick
B1 layer 4" thick
SM I jl Closely interbedded silt layers
Il 20-25'
4 II Tntal ncnth - 11'
No Free Water
No Bedrock
Note:
The stratification lines
represent the approximate
boundaries between the
soil types; the transitions
may be gradual.
APPENDIX B
Summary of Test Results
Table 2
BUENA ENGINERS, INC.
April 5, 1990 B-1 87-2083-1`1
90-04-724
BORING/DEPTH 1@ 0-5' 1@ 8-13' 4@ 0-5' 3@ 0-2' 6@10' 19@15'
USCS
SP
SM
SM
SP
ML
CL
SOIL DESIGNATION
Al
A2
A3
A4
131
C1
MAXIMUM
DENSITY (pcf)
106.3
115.7
118.8
105.7
---
---
OPTIMUM MOISTURE (%)
14.4
11.7
11.9
14.7
---
-"
ANGLE OF INT. FRIC.
32.40
31.40
31.50
35.80
---
---
COHESION (psf)
100
160
175
60
---
---
EXPANSION INDEX
0
0
4
GRAIN SIZE DISTRIBUTION
(%)
GRAVEL
0.0
0.0
0.1
1.2
0.0
0.0
SAND
90.3
74.5
45.3
95.4
1.9
10.4
SILT
7.0
17.3
36.0
1.7
61.9
19.7
CLAY
2.7
8.2
18.6
1.7
36.2
69.9
SOIL DESCRIPTIONS:
All: Grey brown very fine to fine sand (SP)
A2: Brown slightly clayey silty very fine to fine sand (SM)
A3: -Brown clayey very, silty very fine sand (SM)
A4: Grey brown fine to medium sand with trace coarse sand (SP)
131: Brown clayey silt (ML)
C1: Brown slightly sandy silty clay (CL)
BUENA ENGINERS, INC.
April 5, 1990 B-2 B7-2083-P1
90-04-724
1 @ 5.0
10.0
30.0
2@ 5.0
15.0
3@ 2.0
10.0
15.0
4@ 2.0
15.0
20.0
30.0
5@2.0
10.0
15.0
25.0
35.0
40.0
45.0
6@ 2.0
10.0
45.0
7@2.0
5.0
15.0
20.0
25.0
30.0
8@2.0
10.0
15.0
20.0
40.0
92.4
0.6
87%
86.7
1.8
75%
97.0
1.3
82%
86.8
1.2
82%
---
2.2
---
93.1
6.4
88%
90.5
7.1
78%
93.6
8.7
81 %
93.7
1.5
79%
96.0
1.3
90%
92.7
1.2
87%
88.8
1.8
---
103.0
1.1
89%
86.0
0.9
-
100.2
1.0
94%
100.5
0.8
95%
99.5
1.4
84%
87.4
27.1
---
86.8
8.9
---
97.7
1.4
92%
76.8
5.3
---
92.1
1.5
87%
110.4
1.6
95%
94.1
2.4
89%
65.8
6.0
L. � ei
U070
68.4
4.8
58%
83.5
7.3
70%
95.1
3.5
82%
95.6
8.0
80%
---
1.3
---
88.2
2.0
76%
82.1
1.4
77%
81.8
14.9
---
BUENA ENGINERS. INC.
April 5, 1990 B-3 B7-2083-P1
90-04-724
IN -PLACE RELATIVE
BORING, & DEPIL[ DRY DENSITY % MOISTURE COMPACTION
9@2.0
103.0
0.9
97%
20.0
91.7
1.5
79%
11 @5.0
98.1
13.0
83%
10.0
97.7
7.3
84%
20.0
96.8
0.8
91 %
12@2.0
---
2.9
---
5.0
89.0
5.0
75%
10.0
94.7
1.0
89%
15.0
89.9
1.4
85%
13@5.0
101.4
1.9
88%
15.0
92.3
1.7
87%
14@2.0
98.0
4.4
82%
5.0
94.1
1.9
81 %
10.0
91.4
1.1
79%
15.0
95.3
0.9
90%
15@2.0
120.0
4.6
100%
5.0
107.9
3.5
100%
15.0
65.1
3.6
61 %
20.0
89.7
1:8
76%
16@2.0
112.8
9.3
97%
10.0
87.2
2.6
82%
15.0
85.2
2.4
80%
17@2.0
106.9
10.5
92%
5.0
85.9
8.3
72%
10.0
90.9
4.8
77%
20.0
99.9
1.0
95%
18@10.0
80.5
1.4
76%
20.0
75.7
7.1
---
19@2.0
117.1
5.3
100%
5.0
110.3
3.3
100%
10.0
---
3.7
---
15.0
92.5
6.2
80%
20.0
---
3.2
---
25.0
86.2
7.0
---
BUENA ENGINERS. INC.
April 5, 1990 B-4 B7-2083-P1
90-04-724
200a 5.0
15.0
20.0
21 @5.0
20.0
25.0
30.0
35.0
22Ca 5.0
10.0
15.0
2392.0
15.0
98.7
2.4
85%
61.0
11.7
---
88.4
2.9
83%
100.7
0.8
95%
76.3
9.4
---
86.2
10.4
---
85.6
7.0
---
98.1
2.4
85%
99.0
2.8
93%
81.6
6.6
---
67.9
7.9
---
---
1.5
---
106.1
2.4
100%
PII=MA r_Nrlwr-QQ INr,
B 7 — 2 0 8 3 — P 1
MOISTURE CONTENT IN PERCENT OF DRY WEIGHT
co
0
z
O
a
ra
12 14 16
METHOD OF COMPACTION
ASTM D-1557-78, METHOD A or C
SOIL TYPE
Al
Boring 1 @ 0-5'
MAXIMUM DENSITY
106.3pcf
08
06
104
OPTIMUM MOISTURE
14.4%
MAXIMUM DENSITY — OPTIMUM MOISTURE CURVES
B 7 — 2 0 8 3 — P 1
MOISTURE CONTENT IN PERCENT OF DRY WEIGHT
f-
O
LL
U
m 116
V
Q
LU
a
O 114
z
m
a
z
}
~ 112
z
W
O
Q
O
10 12 14
METHOD OF COMPACTION
ASTM D-1557-78, METHOD A or C
SOIL TYPE MAXIMUM DENSITY OPTIMUM MOISTURE
A2 115.7 pcf 11.7%
Boring 1 @ 8-13'
MAXIMUM DENSITY - OPTIMUM MOISTURE CURVES
B7-2083-P1
MOISTURE CONTENT IN PERCENT OF DRY WEIGHT
H
O
LL
U
m 1
V
Q
W
a
0
z
m
O
a
z
a�
z
W
0
cc
0
10 12 14
METHOD OF COMPACTION
ASTM D-1557-78, METHOD A or C
SOIL TYPE MAXIMUM DENSITY
p3 118.8 pcf
Boring 4 @ 0-5'
20
18
116
OPTIMUM MOISTURE
11.9%
MAXIMUM DENSITY - OPTIMUM MOISTURE CURVES
87-2083-P1
4.0
_..N 3.5 —
H
O
0 3.0
d 2.5
Y
2.0
N
W
� 1.5 r
co
0Z_ 1.0
FE
Q
= 0.5
0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
NORMAL LOAD, (KIPS / FOOT )
DIRECT SHEAR DATA
Sail ty p e:
1 @ 0-5'
Be -ring and depth.
Angle of internal friction:
Cohesion: 100 DO
32.40
N Samples remolded to 90% of maximum density
0 Samples relatively undisturbed
8 7 - 2 0 8 3 - P 1
4.
1.5 2.0 2.5 J.0 0.0
NORMAL LOAD (KIPS / FOOT )
DIRECT SHEAR DATA
3til type: a
Baring and depth:
Angle of internal friction: 31.49
Cohesion: 160 DO
Samples remolded to 90% of maximum density
13 Samples relatively undisturbed
B7-2083-P1
4.
a 3.
H
O
0 3.
N
a. 2,
Y
Cn 2
N
W
� 1
C�
Z_ 1
0=
Q
uJ
2
(A
0 0.5 1.0 1.5 2.0 z.a Q.v -T.0
NORMAL LOAD, (KIPS / FOOT )
DIRECT SHEAR DATA
Sail type: A3
BDring and depth: '4 @ 0-5'
Angle of internal friction: 31
Cohesion: 1
0 Samples remolded to 90% of maximum density
❑ Samples relatively undisturbed
B 7 - 2 0 8 3 - P 1
C
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W91121610MILGIN
Premoistening is required where specified in Table 2 in order to
achieve. maximum and uniform expansion of soils prior to
construction and thus limit structural distress caused by uneven
expansion and shrinkage. Other systems which do not include
premoistening may be approved by the Building Official when such
alternatives are shown to provide equivalent safeguards against
adverse effects of expansive soils.
2. Underfloor access crawl holes shall be provided with curbs
extending not less than six (6) inches above adjacent grade to
prevent surface water from entering the foundation area.
3. Reinforcement for continuous foundations shall be placed not less
than three (3) inches above the bottom of the footings and not less
than three (3) inches below the top of the stem.
4. Reinforcement shall be placed at mid -depth of slab.
5. After premoistening, the specified moisture content of soils shall be
maintained until concrete is placed. Required moisture content
shall be verified by an approved testing laboratory not more than
twenty-four (24) hours prior to placement of concrete.
6. Crawl spaces under raised floors need not be premoistened
except under interior footings. Interior footings which are not
enclosed by a continuous perimeter foundation system or
equivalent concrete or masonry moisture barrier complying with
UBC Section 2907 (b) shall be designed and constructed as
specified for perimeter footings in Table 2. ,
7. A grade beam not less than twelve (12) inches by twelve (12) inches
in cross section, reinforced as specified for continuous foundations in
Table 2 shall be provided at garage door openings.
8. Foundation stem walls which exceed a height of three (3) times the
stem thickness above lowest adjacent grade shall be reinforced in
accordance with Sections 2418 and 2614 in the UBC or as required
by engineering design, whichever is more restrictive.
9. Bent reinforcing bars between exterior footing and slab shall be
omitted when floor is designed as an independent, 'floating" slab.
10. Fireplace footings shall be reinforced with a horizontal grid located
three (3) inches above the bottom of the footing and consisting of
not less than number four (#4) bars at twelve (12) inches on center
each way. Vertical chimney reinforcing bars shall be hooked under
the grid.
BUENA ENGINERS. INC.
APPENDIX C
Standard Grading Specifications
BUENA ENGINERS, INC.
C-1
STANDARD GRADING SPECIFICATIONS
PROJECT: ONE ELEVEN LAQUINTA CENTER
CLIENT: TRANSPACIFIC DEVELOPMENT COMPANY
1, These Standard Grading Specifications have been prepared for
the exclusive use of our client for specific application to referenced
project in accordance with generally accepted soil and
foundation engineering practices. No other warranty, expressed or
implied, is made.
2. These specifications shall be integrated with the Engineering Report
of which they are a part. Should conflicting statements be found
between these standard specifications and the itemized
recommendations contained in the main body of the engineering
report, the latter shall govern.
3. Buena Engineers, Inc., referred to as the soil engineer, should be
retained to provide continuous soil engineering services during
construction of the grading, excavation and foundation phases of
the work. This is to observe compliance with the design concepts,
specifications or recommendations and to allow design changes in
the event that subsurface conditions differ,from that anticipated prior
to start of construction.
4. The presence of our field representative will be for the purpose of
providing observation and field testing. Our work does not include
supervision or direction of the actual work of the contractor, his
employees or agents. The contractor for this project should be so
advised. The contractor should also be informed that neither the
presence of our field representative nor the observation and testing
by our firm shall excuse him in any way from defects discovered in
his work. It is understood that our firm will not be responsible for job or
site safety on this project. Job and site safety will be the sole
responsibility of the contractor.
5. If the contractor encounters subsurface conditions at the site that (a)
are materially different from those indicated in the contract plans or
in specifications, or (b) could not have been reasonably
anticipated as inherent in the work of the character provided in the
contract, the contractor shall immediately notify the owner verbally
and in writing within 24 hours. This notification shall be a condition
precedent before any I;egotiations for "chan;,ed or differing site
conditions` can proceed. if the owner determines that conditions
do materially so differ and cause an increase or decrease in the
BUENA ENGINERS, INC.
c-z
contractor's cost of, or the time required for, performance of any
part of the work under this contract, then negotiations shall
commence between owner and contractor to provide equitable
adjustment to owner or contractor resulting therefrom.
6. Whenever the words 'supervision', 'inspection', or 'control' appear
they shall mean periodic observation of the work and the taking of
soil tests as deemed necessary by the soil engineer for substantial
compliance with plans, specifications and design concepts.
7. These specifications shall consist of clearing and grubbing,
preparation of land to be filled, filling of the land, spreading,
compaction and control of the fill, and subsidiary work necessary to
complete the grading of the filled areas to conform with the lines,
grades and slopes as shown on the accepted plans.
8. The standard test used to define minimum censities or co. pa�.iivri
work shall be the ASTM Test Procedure D 1557. Densities shall be
expressed as a relative compaction in terms of the maximum
density obtained in the laboratory by the foregoing standard
procedure.
9. Field density tests will be performed by the soil engineer during
grading operations. At least one (1) test shall be made for each five
hundred (500) cubic yards or fraction thereof placed with a
minimum of two (2) tests per layer in isolated areas. Where
sheepsfoot rollers are used, the soil may be disturbed to ❑ depth of
several inches. Density tests shall be taken in compacted material
below the disturbed surface. When these tests indicate that the
density of any layer of fill or portion thereof is below the required
density, the particular layer or portion shall be reworked until the
required density has been obtained.
10. Earth -moving and working operations shall be controlled to prevent
water from running into excavated areas. Excess water shall be
_i LL- .,i_ i,r r%+ Ary Kili mriterid shall not he
prompf y rernoveu Q G 111tv Q,1v •,Gr-1 - 7 . - .., ..._. _.. _. - _.. - -
placed, spread or rolled during unfavorable weather conditions.
When the work is interrupted by heavy rain, fill operations shall not be
resumed until field tests by the soil engineer indicate that the
moisture content and density of the fill are as previously specified.
11. Compaction shall be by sheepsfoot rollers, vibrating sheepsfoot
rollers, multiple -wheel pneumatic -tired rollers or other types of
acceptable compacting rollers. Rollers shall be of such design that
they will be able to compact the fill to the specified density. Rolling
shall be accomplished while the fill material is within the specified
moisture content range. Rolling of each layer shall be continuous
over its entire area and the roller shall make sufficient trips to insure
that the required density has been obtained.
12. Existing structures, foundations, trash, debris, loose fill, trees (not
included in landscaping), roots, tree remains and other rubbish shall
be removed, piled or burned or otherwise disposed of so as to
BUENA ENGINERS. INC.
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leave the areas that have been disturbed with a neat and finished
appearance free from debris. No burning shall be permitted in the
area to be filled.
13. When fUt material includes rock, large rocks will not be allowed to
nest and'voids must be carefully filled with small stones or earth and
properly compacted. Rock larger than eight (8) inches in diameter
will not be permitted in the compacted fill without review as to
location by the soil engineer.
14. Organic matter shall be removed from the surface upon which the
fill, foundations or pavement sections are to be placed. The surface
shall then be plowed or scarified to a depth of at least eight (8)
inches and until the surface is free from ruts, hummocks or other
uneven features which would tend to prevent uniform compaction
by the equipment to be used. Specific recommendations
pertaining to stripping and minimum depth of recompaction of
native soils are presented in the main body of the soil report.
15. Native soil free from organic material and other deleterious material
may be used as compacted fill; however, during grading
operations the soil engineer will re-examine the native soils for
organic content.
16. Imported material should be tested and reviewed by Buena
Engineers, Inc., before being brought to the site. The materials used
shall be free from organic matter and other deleterious material.
17. Where fills are made on hillsides or exposed slope areas, greater
than ten (10) percent, horizontal benches shall be cut into firm
undisturbed natural ground to provide a horizontal base so that
each layer is placed and compacted on a horizontal plane. The
initial bench at the toe of the fill shall be at least ten (10) feet in width
on firm, undisturbed natural ground at the elevation of the toe stake
placed at the natural angle of repose or design slope. The width
and frequency of succeeding benches will vary with the soil
conditions and the steepness of slope.
18. The selected fill material shall be placed in layers which, when
compacted, shall not exceed six (6) inches in thickness. Layers shall
be spread evenly and shall be thoroughly blade -mixed during
spreading. After each layer has been placed, mixed and spread
evenly, it shall be thoroughly compacted to a relative compaction
of not less than ninety (90) percent. The fill operation shall be
continued in six (6) inch compacted layers, as specified above, until
the fill has been brought to the finished slopes and graded as shown
on the accepted plans.
19. When the moisture content of the fill material is not sufficient to
achieve required compaction, .)ct -Dr shall be added until the soil:.
attain a moisture content so that thorough bonding is achieved
BUENA ENGINERS, INC.
C-4
during the compacting process. When the moisture content of the fill
material is excessive, the fill material shall be aerated by blading or
other satisfactory methods until the moisture content is reduced to
an acceptable content to achieve proper compaction.
20. Existing septic tanks and other underground storage tanks must be
removed from the site prior to commencement of building, grading
or fill operations. Underground tanks, including connecting drain
fields and other lines, must be totally removed and the resulting
depressions properly reconstructed and filled. Depressions left from
tree removal shall also be properly filled and compacted.
21. The methods for removal of subsurface irrigation and utility lines will
depend on the depth and location of the line. One of the following
methods may be used: 1) Remove the pipe and compact the soil
�� _ a_�....�. .....,.�;.... +„ +h= rnnnfirnhIp nnrtions of these aradinq
recommendations, 2) The pipe shall be crushed in the trench. The
trench shall then be filled and compacted according to the
applicable portions of these grading specifications, 3) Cap the
ends of the line with concrete to mitigate entrance of water. The
length of the cap shall not be less than five (5) feet. The concrete
mix shall have ❑ minimum shrinkage.
22. Abandoned water wells on the site shall be capped according to
the requirements of the appropriate regulatory agency. The
strength of the cap shall be at least equal to the adjacent soils. The
final elevation of the top of the well casing must be a minimum of
thirty-six (36) inches below adjacent grade prior to grading or fill
operations. Structure foundations should not be placed aver the
capped well.
BUENA ENGINERS. INC.
RECEIVED
' AY 1 4 1990
Buena Engineers, Inc. M
AN Wfl1 •r*RNN, IMQ COMPANY
� nGVF-! OP�y?FNT D'cPARTMENT
79-811 B COUNTRY CLUB DRIVE - BERMUDA DUNES, CALIFORNIA 92201 - PHONE (619) 345-1588 FAX (619) 345-7315
May 10, 1990 B7-2083-P1
90-05-785
Transpacific Development Company
2377 Crenshaw Boulevard
Torrance, California 90501-3325
Attention: Keith Holmes
Project: 111 La Quinta Center
La Quinta, California
Ref: Geotechnical Engineering Report by Buena Engineers, Inc.
dated April 5, 1990; Report No. 90-04-724
This letter is concerning the additional two and six tenths (2.6) acre site to the north of
the Whitewater Channel and the channel crossing along Adams street. The site plan
for this portion of the project was inadvertently omitted from the referenced report. The
plan is attached with the approximate boring locations indicated. The corresponding
boring logs are included in the referenced report.
If there are any questions concerning this letter or the referenced report please contact
the undersigned. I apologize for any inconvenience.
Respectfully submitted,
BUENA ENGINEERS,
Brett L. Anderson, P.E.
BLA/ss
HD/LTRS
Iff
Copies: 4 - Transpacific Development Company
1 - VTA File
1 - PS File
BERMUDA DUNES BEAUMONT BAKERSRELD LANCASTER VENTURA
16191345-1588 (714) 845-9883 (805) 327-5150 (805) 948-7538 (805) 642-6727
ti�
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Buena Engineers, Inc.
DATE: 5'-/0 -90 1 FILE NO.:/37-2*83-PJ