9806-133 (RC) Soil Engineering ReportSOIL ENGINEERING REPORT
JOHNSON OFFICE BUILDING
LA QUINTA, CALIFORNIA
PREPARED FOR
WARREN JOHNSON
B7-Ob47-P1
FEBRUARY 14, 1989
BUENA ENGINEERS, INC.
% ""I
'Buena Engineers, Inc.
T1 00F AN EARTH SYSTEMS, INC. COMPANY
' 79-811 COUNTRY CLUB DRIVE SUITE #4 • BERMUDA DUNES, CALIFORNIA 92201 • (619) 345-1588
February 14, 1989 87-0647-P 1
' 89-02-725
' Marren Johnson
35 West Orange Grove Avenue
Arcadia, California 91000
Project: Johnson Office Building
La Qui nta, California
Subject: Soil Engineering Report
Presented herewith is our Soil Engineering Report prepared for the proposed
single family residence to be located in La Qui nta, California. .
This report incorporates the tentative information supplied_ to our office,
and in accordance with the request, recommendations for general site
development and foundation design are provided.
This report completes our scope of services in accordance with our
agreement. Other services which may be required, such as plan review and
grading observation are additional services and will be billed according to
the Fee Schedule in effect at the time services are provided.
Please contact the undersigned if there are any questions concerning this
report or the recommendations included herein..
Respectfully s
BUENA ENGI
l�
Jo eph R. b'e
Civil Engi lee
JRV/mea
HD
Copies:
3.31.91
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h\&F CAL1F��
6 - Marren Johnson
1 -P. S. File
1 - VTA File
VENTURA
(805) 642-6727
LANCASTER
(805) 948-7538
BAKERSFIELD SANTA BARBARA BERMUDA DUNES SAN LUIS OBISPO
(805) 327-5150 (805) 966-9912 (619) 345-1588 (805) 544-6187
[I
TABLE OF CONTENTS
INTRODUCTION .......................................................................................
1
PURPOSE AND SCOPE OF WORK ------------------------------------------------------------
l
SITE DESCRIPTION................................................................................
2
FIELD EXPLORATION------------------------------------------------------------------------------
3
LABORATORY TESTING --------------------------------------------------------------------------
3
SOIL CONDITIONS---------------------------------------------------------------------------------
4
GROUNDWATER---------------------------------------------------------------------------------------
5
CONCLUSIONS----------------------------------------------------------------------------------------
5
RECOMMENDATIONS -------------------------------------------------------------------------------
5
SITE DEVELOPMENT AND GRADING ------------------------------------------------------
6
Site Development - Grading--------------------------------------------------------------
6
Site Development - General--------------------------------------------------------------
7
Excavations--------------------------------------------------------------------------------------
9
TrafficAreas-----------------------------------------------------------------------------------
10
Uti1 i ty Trenches-------------------------------------------------------------------------------
10
STRUCTURES------------------------------------------------------------------------------------------
10
Foundations--------------------------------------------------------------------------------------
11
Slabs-on-Grade--------------------------------------------------------------------------------
12..
Settlement Considerattons_______________________________________________________________
13
Frictional and Lateral Coefficients..........................:.......................
13
SlopeStability---------------------------------------------------------------------------------
14
Expansion-----------------------------------------------------------------------------------------
14
Additional Services--------------------------------------------------------------------------
14
LIMITATIONS AND UNIFORMITY OF CONDITIONS -------------------------------
15
APPENDIX A
Site and vicinity Map
Logs of Barings
APPENDIX B
Summary of Test Results
Table 29-A
APPENDIX C
Standard Grading Specifications
BUENA ENGINEERS, INC.
February 14, 1989
INTRODUCTION
87-0647-P1
89-02-725
This Soil Engineering Report has been prepared for the proposed two (2)
story office building. It has been proposed to construct the office building
in the La Quinta area of Riverside County, California.
A. It is assumed that the proposed structure will be of lightweight one or
' two story construction. The exact foundation type of structures is not
known at this time.
6. Structural considerations for building column loads of up to 25 kips and
a maximum wall loading of 2.0 kips per linear foot were used.as a basis
for recommendations of the report. as provided herein. These are
estimated values since we did not have foundation plans available at
the time of production of this report.
C. All loading is assumed to be dead plus reasonable live load.
PURPOSE AND SCOPE OF WORK
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.
8. Shallow subsurface exploration by drilling.
C. Laboratory testing of selected soil samples obtained from the
exploratory borings drilled for this project.
D. Evaluation of field and laboratory data relative to soil conditions.
E. Engineering analysis. of the data obtained from the exploration and
testing programs.
F. A summary of our findings and recommendations in written report.
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IContained In This Report Are:
' A. Discussions on soil conditions.
B. Graphic and/or tabulated results of laboratory tests and field studies.
1
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 Is:
' A. This report does not evaluate the geology of the site in any manner.
' B. This report does not address the potential seismic hazards of the site.
' SITE DESCRIPTION
The site of the proposed project is located on the northeast corner of
Avenida Bermudas and Calle Cadiz in the La Ruinta area of Riverside County,
California.
A. Upon our arrival for percolation testing, the site of the proposed
structure was covered with short grass, weeds and some debris.
B. The property was basically level throughout before the percolation
testing began.
C. On our subsequent arrival to perform drilling, our crew noted that two
' (2) large palm trees were removed from the building area and placed in
the parkway area.
' D. The building area was excavated to a depth of three (3) feet below
finish pad grade. The excavation soil was placed in two (2) large
stockpiles.
E. There are existing underground utilities along the street and possibly
' along the alley behind the property.
I' BUENA ENGINEERS, INC.
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FIELD EXPLORATION
Exploratory borings were drilled for observing the soil profile and obtaining
samples for further analysis.
A. Two (2) borings were drilled for soil profiling and sampling to a
maximum depth of twenty-one (21) feet below the existing ground
surface. Borings were drilled on February 6, 1989, using an eight (8)
inch diameter hollow -stern auger powered by a C.ME 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 (1) foot was
recorded. Recovered soil samples were sealed in containers and
returned to the laboratory for further classification and testing.
C. Bulk disturbed samples of the soils were obtained from cuttings
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.
LABORATORY TESTING
' After a visual and tactile classification in the field, samples were returned
to the laboratory, classifications were checked, and a testing program was
established.
III
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SOIL CONDITIONS
' As determined by the borings, site soils were found to consist primarily of
fine silty sands with interbedded silt layers. The baring logs in Appendix A
contain a more detailed description of the soils encountered.
A. Soils were found to be very loose with several of the in-place densities
' below eighty-five (85) percent of maximum density.
B. Interbedded silt layers up to three (3) feet thick were encountered in
' all of the borings.
C. The consolidation test data indicates a susceptibility to considerable
settlement due to hydroconsolidation of the silt layers.
BUENA ENGINEERS, INC.
A.
Samples were reviewed along with field logs to determine which would
be further analyzed. Those chosen were considered as representative 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 hts for the core samples
were developed in accordance with ASTM D 2937.
1
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 KSF.
D.
Settlement .and hydroconsolidation potential was evaluated from the
'
results of consolidation tests performed in accordance with ASTM
2435.
'
E.
Classification tests consisted of: Expansion Index (UBC Standard No.
29-2), Maximum Density -Optimum Noisture (ASTM D 1557), and
'
Hydrometer Analysis (California Test Method 203).
F.
Refer to Appendix B for tabular and graphic representation of the test
'
resul ts.
SOIL CONDITIONS
' As determined by the borings, site soils were found to consist primarily of
fine silty sands with interbedded silt layers. The baring logs in Appendix A
contain a more detailed description of the soils encountered.
A. Soils were found to be very loose with several of the in-place densities
' below eighty-five (85) percent of maximum density.
B. Interbedded silt layers up to three (3) feet thick were encountered in
' all of the borings.
C. The consolidation test data indicates a susceptibility to considerable
settlement due to hydroconsolidation of the silt layers.
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'
D. Clay and silt contents of the soils exhibit low plasticity. Expansion
tests indicate soils to be in the "medium" expansion category in
'
accordance with Table 29-A in Appendix B of this report. Refer to
section F of the structures section for specific explanations and
'
requirements dealing with expansive soil.
1
E. Soils should be readily cut by normal grading equipment.
GROUNDWATER
Free groundwater was not encountered in any of the borings. However, the
groundwater level in the vicinity of the site is in excess of seventy (70)
'
feet below the ground surface. Fluctuations in groundwater levels may
occur due to variations in rainfall, temperature and other factors.
CONCLUSIONS
'
site ° the a
The ,� to �s suitable far proposed project from a soil engineering
'
standpoint.
' RECOMMENDATIONS
Based on our interpretation of the data obtained and our understanding of
' the proposed construction, the following recommendations are provided and
represent professional opinions.
1. It is recommended that any permanent structure constructed on the
sites be designed to at least minimum requirements for Seismic Zone
4 based on the latest edition of the Uniform Building Code.
2. Adherence to the following grading recommendations is necessary to
' mitigate potential settlement problems.
I I
III
' BUENA ENGINEERS, INC.
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SITE DEVELOPMENT AND GRADING
Prior to any construction operations, areas to be graded should be cleaned of
vegetation and other deleterious materials. Appendix C, "Standard Grading
Specifications" contains specific suggestions for removal and disposal of
deleterious substances and, as such, forms a part of these Site Development
and Grading Recommendations.
A. Site Development - GradinQ
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
overexcavati on.
1. To control differential settlement and to produce a more uniform
bearing condition, foundations should bear on compacted soils.
Compaction is to be verified by testing.
2. Due to the hydroconsolidation susceptibility of the silt layers
'
encountered in each of the borings, which if unmitigated could
result in settlements of up to three (3) inches, extensive grading
is recommended.
3. Building areas should be overexcavated to a depth of four (4) feet
'
below original grade or the bottom of footings, whichever is
greater. The exposed surface should be scarified, moisture
conditioned and recompacted so that a rnininurn of ninety (90)
percent of maximum density is obtained. The previously removed
soils and any fill material should then be placed in eight (8) inch
layers in a loose condition at or near optimum moisture and
'
compacted to a minimum of ninety (90) percent of maximum
density. The intent is to have at least five (5) feet of soil
compacted to a minimum of ninety (90) percent of
maximum density compose the building pad beneath the
footings. Compaction is to be verified by testing.
t4.
These grading requirements apply to building areas and at least
five (5) feet beyond building limits.
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5. Auxiliary stuctures including freestanding or retaining malls shall
' have the existing soils beneath the structure processed as per
item three (3) above. The grading requirements apply to three (3)
feet beyond the face of the walls. If we are allowed to review
' plans for auxiliary structures, the above recommendations may be
modified.
' 6. It is anticipated that during grading a loss of approximately two
tenths (2) of a foot due to stripping, and a shrinkage factor of
about fifteen (15) to twenty (20) percent for the upper four (4)
' feet of soil, may be used for quantity calculations. This is based
on compactioe 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) and three -tenths
t (3) of a foot.
' B. Site Development - General
1. The following "general" requirements listed in this section will
I
be superceded by the recommendations in the 'Grading' section
A above.
2. The existing ground surface should be initially prepared for
structures by removing vegetation, weeds, noncomplying fill or
other incompetent material. Roots should be extracted and pickers
used to remove oversized roots from fill soils. 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 resultingfrom removal under item one above. In
general, all proposed construction should be supported by a
uniform thickness of compacted soil.
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4. Previously removed soils; once cleaned of rocks larger than eight
(8) inches in greatest dimension, and other deleterious material,
may be placed in thin layers and mechanically compacted back to
finish grade.
5. , Import soil used to raise site grades should be equal to or better
than on-site soil in strength, expansion, and compressibility
characteristics. Import soil may be prequalified by Buena
Engineers, Inc. Comments on the characteristics of import will be
given after the material is on the project, either in-place or in
stockpiles of adequate quantity to complete the project.
6. Fill and backfill should be compacted to the minimum of ninety
(90) percent of maximum dry density obtained by the ASTM D 1557
test method. Our "Standard Grading Specification;" contained in
Appendix C of this report, and Chapter 70 of the Uniform Building
Code contain specific considerations for grading and form a part of
this report.
7. Areas around the structures should be graded so that drainage is
positive and away from the structures. Gutters and down spouts
should be considered as a way to convey water out of the
foundation area. Water should not be allowed to pond on or near
pavement sections.
8. Added moisture within previously compacted fill could result in a
number of reactions at the surface depending upon the amount of
moisture increase, the in-place density of the soil, in-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).
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9. The obvious 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.
10. Failure to control increase in moisture content to compacted fill
could result in settlement which could compound the problem by
rupturing water :lines or other services and/or utilities, thus
introducing additional moisture into the underlying soil.
11. 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 soil engineering report.
Chapter 70 of the Uniform Building Code contains specific
considerations for grading and is considered a part of these
recommendations.
12. 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. Excavations
1. All excavations should be made in accordance with applicable
regulations. From our site exploration and knowledge of general
area, we feel there is a potential for construction problems
involving caving of relatively deep site excavations (i.e. utilities,
etc.). Where such situations are encountered, lateral bracing or
appropriate cut slopes should be provided.
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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.
i
D. Traffic Areas
1. 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) foot of subgrade
compacted to ninety (90) percent of maximum density.
' 3. Final preparation of subgrade will depend on paving section
designs.
' E. Utility Trenches
1. Backfill of utilities within road right-of-way should be placed in
' strict conformance with the requirements of the governing agency
(dater District, Road Department, etc.).
2. Utility trench backfill within private property should be placed in
strict provisions of this report relating to minimum compaction
' standards. In general, service lines extending inside of property
may be backfilled with native soils compacted to a minimum of
ninety (90) percent of maximum density.
3. Backfill operations should be observed and tested by Buena
Engineers, Inc., to monitor compliance with these
recommendations.
STRUCTURES
Based upon the results of this evaluation, it is our opinion that structure
foundation can be supported by compacted sails placed as recommended
above. The recomendations that follow are based on very low" expansion
category soi Is.
1
' BUENA ENGINEERS, INC-.
February 14, 1989 -11- B7 -0647-P 1
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A. Foundations
' It is anticipated that foundations will be placed on firm compacted
soils as recommended elsewhere in this report. The recommendations
that follow are based on "very low" expansion category soils.
1. Table 29-A gives specific recommendations for width, depth and
' reinforcing. Reinforcing requirements will be determined by Table
29-A per expansion testing required during grading. (see F of this
section). Other structural considerations may be more stringent
' and would govern in any case.
' 2. Conventional Foundations:
Estimated bearing values are given below for foundations on
trecompacted soils, assuming fill import (if required) to be equal
to or better than site soils:
a. Continuous foundations of fifteen (15) inches 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. 1700 psf for dead plus reasonable live loads.
' ii. 2260 psf for wind and seismic considerations.
3. Allowable increases of 250 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.
' 4. Footing reinforcement is not required per Table 29-A; however,
one (1) number four (#4) rebar at top and bottom of footings is
suggested 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.
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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 to 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
surcharge may be neglected)
reasonable live loads.
net (weight of footing and soil
and are applicable for dead plus
B. Slabs -on -Grade
1. Concrete slabs -on -grade should be supported by compacted
'
structural fill placed in accordance with applicable sections of
this report.
'
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. The membrane
should be covered with two (2) inches of sand to help protect it
during construction. The sand should be lightly moistened just
'
prior to placing the concrete.
.3. Reinforcement of slab -on -grade is contingent upon the structural
t
engineers recommendations. and the expansion index of the
supporting soil. Since the mixing of fill 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 high temperature differential
endemic to desert areas, large concrete slabs on grade are
susceptible to tension cracks. As a minimum, we recommend
that all interior concrete slabs -on -grade be reinforced with 6"x,
6"!* 10 x# 10 welded wire fabric. Reinforcement due to the
expansion index of the site sail should be provided as
recommended -in section F below. Additional reinforcement may
also be required by the structural engineer.
I
BUENA ENGINEERS, INC.
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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. Settlement Considerations
1. Maximum estimated settlement, based on footings founded on firm
soils as recommended, should be less than one (1) inch.
Differential settlement between exterior and .interior bearing
members should be less than one-half (1/2) inch.
2. The majority of settlement should occur during construction.
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 .47 may be
used for dead load forces.
' 2. Passive resistance acting on the sides of foundation stems (280
pcf, equivalent fluid weight), may be included for resistance to
lateral load.
3. A ane -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 retainingwalls backfilled `with compacted native soil it is
P
' recommended that an equivalent fluid pressure of thirty-five (35)
pcf be used for well drained level backfill conditions.
1
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E
F.
G.
Slope Stabilitu
Slope stability calculations were not performed due to the anticipated
minimal slope height (less that 5'). 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.
Expansion
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 preliminary expansion index of the on-site soil
is in the very low (0-20) classification. However, during site
preparation, if the soil is throughly 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.
Additional Services
This report is based on the assumption that an adequate program of
client consultation, construction monitoring and testing will be
performed during the final design and construction phases to check
compliance with these recommendations. Maintaining Buena Engineers,
Inc., as the soil engineering firm from beginning to end of the project
will help assure continuity of services. These test 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.
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February 14, 1989 -15- B7 -0647-P 1
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LIMITATIONS AND UNIFORMITY OF CONDITIONS
The analysis and recommendations submitted in this report are based in part
upon the data obtained from the two (2) borings performed on the site. The
nature and extent of variations between the borings may not become evident
until construction. If variations then appear evident, it will be necessary to
reevaluate the 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 one ( 1) year_
In the event that any changes in the nature, design or location of the
building are planned, 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 incorporated into the plan and
that the necessary steps are taken to see that the contractor and
subcontractors carry out such recommendations in the field. it is further
understood that the owner or his representative is responsible
for submittal of this reprt to the appropriate governing agencies_
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.
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February 14, 1989 -16- 87 -0647 -PI,
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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.
END OF TEXT
Appendices
BUENA ENGINEERS, INC
APPENDIX A
Site and Vicinity Mop
Logs of Borings
BUENA ENGINEERS, INC.
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PROPOS
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1 ��
, ,i FF: x8.44 Mil = ' • I` n ,
PA -47.4 '' - Ps'0.SED �^.N B, PROJECT SITE f
d .
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4, VICINITY MAP
4
j1 r -27'0
A ^.67
J
cp
COs' -REQ K.L� K a . �.
ilIBT'G 9_OCK
TO BE REwOVED
FOUNDNAIL S TAG a)• ' 'yT .
(<6.7); ON TOP OF K'ALL \ - I �_ •.. �'.Y 1'
(<6.]0'21:1 w. C. /^/\ I \ ':JRS1:I 1i 3
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SEPTIC TAM[
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C, 144 tT .,t • FOR FUTURE COr`VEC'f10N
�� p 'E P
\►, C I
N ,9 v�v io q ,Z3e�eif u,a.�s
47 1 LA QLiNr-4'
( BUENA ENGINEER!
1 DAZE: 2_ �Q _act JOB NC
I -
DATE February 6, 1989
LOG OF BORING
for
Johnson Office Building
BORING NO. 1
Job No. B7 -0647-P1
Report No.. 89-02-725
LOCATION Per Plan
j1
o.
o
1'
ono
°.'
3
m
DESCRIPTION
3
w
a
���
0
� L
p0
� a
o
V)
C
0
+
? a
vow
OR U
REMARKS AND ANALYSIS
5
1
.,
.1 ,
`
19
17
19
33
39
Al: Brown slightly clayey very
silty very fine sand
.86.9
84.6
93.0
2.9
3.0
1.9
SM
77
75
83
A2: Grey brown slightly silty
very fine to fine sand
SM
10
Al: Brown slightly clayey very
silty very fine sand
97.4
101.8
2.4
3.1
SM
87
91
-1 5
Relatively undisturbed ring
sample
Total Depth = 16'
No Freewater
No Bedrock
Note:
The stratification lines
represent the approximate
boundaries between the soil
types; the transitions may
be gradual.
ni — n
DATE February 6, 1989
LOG OF BORING.
for
Johnson Office Building
BORING NO. 2
Job No. B7 -0647-P1
Report No. 89-02-725
LOCATION Per Plan
.-.
s
Q.
0
o
E
i
v
V)
a
H
o
co
DESCRIPTION
`'
�^
a
���
ac,
L
o v
�a
F
o
N
c
o
? n. `
`ti E L
�
Va
I UA
REMARKS AND ANALYSIS
0
'
'
;
17
23
�5
28
50
Al: See Below
SM
A2: Grey brown slightly silty
very fine to fine sand
90.4
4.1
SM
80
5T
1
Al: Brown slightly clayey very
silty very fine sand
95.2
84.3
89.3
97.9
7.1
5.3
3.4
6.0
SM
85
75
80
87
10
15
20
Relatively undisturbed ring
ample
Total Depth = 21'
No Freewater
No Bedrock
Note:
The stratification lines
represent the approximate
boundaries between the soil
types; the transitions may
be gradual.
ni...,. n
F1,
LJ1
' APPENDIX B
' Summary of Test Results
Table 29-A
1
� I
� I
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BUENA ENGINEERS, INC.
February 14, 1989 B-1 B7 -0647-P 1
89-02-725
SOIL DESCRIPTIONS:
Al: Brown slightly clayey very silty very fine sand (SM)
A2: Grey brown slightty silty very fine to fine sand (SM/SP)
81: Brown slightly sandy clayey silt (ML)
BUENA ENGINEERS; INC.
TEST RESULTS
BORING/DEPTH
1@ 0-3'
2@ 2-4'
1@ 5'
USCS
SM
SM/SP
ML
SOIL DESIGNATION
Al
A2
51
MAXIMUM
DENSITY (pcf)
112.3
104.6
---
--OPTIMUM
OPTIMUMMOISTURE
14.1
12.2
---
ANGLE OF INT. ERIC.
31.0°
32.20
---
COHESION (psf)
94
37
---
EXPANSION INDEX
0
0
0
GRAIN SIZE DISTRIBUTION M
GRAVEL
0.0
0.1
0.0
SAND
54.3
82.9
12.5
SILT -
33.6
9.8
65.8
CLAY
12.1
7.2
21.7
SOIL DESCRIPTIONS:
Al: Brown slightly clayey very silty very fine sand (SM)
A2: Grey brown slightty silty very fine to fine sand (SM/SP)
81: Brown slightly sandy clayey silt (ML)
BUENA ENGINEERS; INC.
February 14, 1989 B-2 67-0647-P 1
89-02-725
BORING & DEPTH
101.0
3.0
5.0
10.0
15.0
IN-PLACE DENSITIES
DRY DENSITY
86.9
84.6
93.0
97.4
101.8
MOISTURE
2.9
3.0
1.9
2.4
3.1
RELATIVE
COMPACTION
77%
75%
83%
87
91 %
2@ 2.0
90.4
4.1
80%
5.0
95.2
7.1
85%
10.0
84.3
5.3
75%
15.0
89.3
3.4
80%
20.0
97.9
6.0
87%
BUENA ENGINEERS, INC.
67-0647-P1
MOISTURE CONTENT IN PERCENT OF DRY WEIGHT
H
O
LL
_U
m 114
U
Q '
W
a
z 112
Z
a
z
110
z
W
}
D
12 14 16
METHOD OF COMPACTION
ASTM D-1557-78, METHOD A or .0
SOIL TYPE MAXIMUM DENSITY OPTIMUM MOISTURE
Al
Boring 1 @ 0-3' 112.3 pcf 14.1 %
MAXIMUM DENSITY--. OPTIMUM MOISTURE CURVES
B7 -0647-P1
MOISTURE CONTENT IN PERCENT OF DRY WEIGHT
O
L
U '
m 106
U
W
CL
Z 104
O
CL
�z
}
102
z
W
O
}
Q:
10 12 14
METHOD OF COMPACTION
ASTM D-1557-78, METHOD A or C
SOIL TYPE MAXIMUM DENSITY OPTIMUM MOISTURE
A2
Boring 2 @ 2-5' 104.6 pcf 12.2 %
MAXIMUM DENSITY - OPTIMUM MOISTURE CURVES
4.
a 3.
O
O0 3.
a 2.
Y
v
2.
w
�
1.
co
Z 1,1
cr
Q
W
= 0.
5 f-
-in
IM
4r
P10
B7 -0647-P1
0, 1 1 1 1 1 r 1
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
NORMAL LOAD (KIPS / FOOT )
DIRECT SHEAR DATA
Soil type: Al
Boring and depth: 1 @ 0-3'
Angle of internal friction: 31.0'
Cohesion: 94 Psf
®
Samples
remolded
to 90% of maximum.density
❑
Samples
relatively
undisturbed
B7 -0647-P1
0 r I i I I I I II
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
NORMAL LOAD (KIPS / FOOT )
DIRECT SHEAR DATA
Soil type: A2
Boring and depth: 2 @ 2-4'
Angle of internal friction:
Cohesion: 37 psf
4.0
remolded
to 90% of maximum density
a
3.5-
relatively
undisturbed
0
0
3.0
W
2.5
Y
v
2.0
w
1.5-
0
Z
1.0
0:
Q
=
0.5
0 r I i I I I I II
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0
NORMAL LOAD (KIPS / FOOT )
DIRECT SHEAR DATA
Soil type: A2
Boring and depth: 2 @ 2-4'
Angle of internal friction:
Cohesion: 37 psf
Samples
remolded
to 90% of maximum density
❑
Samples
relatively
undisturbed
TABLE NO. 29-A
MINIMUM FOUNDATION REQUIREMENTS
Footings for Slab
do Raised Floor Systems (2) (5) (10)
Concrete Slabs
3Y:" Minimum
Thickness
v
All Peri-
Interior foot-
Reinforce-
,
v
-Y
meter
ings for slab
ment for
Premoistening
Weighted
;'
.;
0
t
Footings
and raised
continuous
control for soils
Piers under
Expansion3
_c
F-
(6)
floors (6)
footings
g
Reinforce-
Total
under footings,
g
raised floors
Index
�,
t-
oo
c
tLc
c
(3) (8)
ment (4)
thickness
piers and slabs
Depth below natural
o
E
o
o
of sand
(5) (6)
Z
°10
vi
U.
0
LL.
surface of ground
and finish grade
0-20
1
6
12
6
12
12
None
6x6-
Moistening of
Piers allowed
Very Low
2
8
15
7
18
18
Required
10/10
ground prior to
for single
(Non -Ex-
3
10
18
8
24
24
WWF
2"
placing concrete
floor loads
pansive)
recommended
only
1
6
12
6
15
12
120% of optimum
2
8
15
7
18
1.8
moisture contetit
Piers allowed
21-50
3
10
18
8
24
24
144 top
6x6- I
to a depth of
fpr single
Low
and bottom
10/10
4"
21" below lowest
floor loads
WWF
adjacent grade.
only
Testing Required
1
6
12
6
21
12
144 top
6x6-
130% of optimum
2
8
12
8
21
18
and bottom
6/6 WWF
molsture content
51-90
3
10
15
8
24
24
or #3
to a depth of 27"
Piers not
Medium
24" e.w.
4"
below lowest
allowed
ars @ 24" in ext. footing
adjacent grade.
and bent 3' into slab (9)
Testing Required
1
6
12
6
27
12
145 top
6x6-
140%. of optimum
2
8
12
8
27
18
and bottom
6/6 WWF
moisture content
91-130
3
10
15
8
27
24
or #3
to a depth of 33"
Piers not
High
I
@ 24" e.w.
4"
below lowest
allowed
adjacent grade.
ars 4" in ext, footing
and bent 3' into slab (9)
Testing Required
Above 130
Very High
Special Design by Licensed Engineer/Architect
Refer to next name for footnotes. (1) throijrh (Ip)
FOOTNOTES TO TABLE 29-A
Premoistening is required where specified in Table 29-A in order to achieve
maximum end uniform expansion of soils prior to construction and thus limit
structural distress caused by uneven expansion end shrinkage. Other systems
which do not include premoistening may be approved by_ the Building Officiel
when such alternatives ere shown to provide equivalent safeguards against.
adverse effects of expensive sails.
2. Underfloor access crawl holes shell be provided with curbs extending not less
then six (6) inches above adjacent grade to prevent surface water from
entering the foundetion area.
' 3. Reinforcement for continuous foundations shell be placed not less then three
(3) inches above the bottom of the footings and not less then three (3) inches
below the top of the stem.
' 4. Reinforcement shall be placed at mid -depth of slab.
' S. After premoistening, the specified moisture content of soils shell be
maintained until concrete is placed. Required moiture content shell be
verified by an approved testing laboratory not more then 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 ere not enclosed by a continuous
perimeter foundation system or equivalent concrete. or masonry moisture
barrier complying with UBC Section 2907 (b) shell be _designed and
constructed as specified for perimeter footings in Table 29-A.
7. A grade beam not less than twelve (12) inches bg twelve (12) inches in cross
' section, reinforced as specified for continuous foundations in Table 29-A
shell be provided at garage door openings.
' 8. Foundation stern wells which exceed a height of three (3) times the stem
thickness above. Iowest adjacent grade shall be reinforced in accordance with
Sections 2418 end 2614 in the UBC or as required by engineering design,
whichever is more restrictive.
I9. Bent reinforcing bars between exterior footing and slab shall be omitted when
floor is designed as en independent, "floating' slab.
' 10. Fireplace footings shell be reinforced with a hori2onel grid located three (3)
inches above the bottom of the footing and consisting of not less then number
four (*4) bars at twelve (12) inches on center each way. Vertical chimney
reinforcing bars shell be hooked under the grid.
BUENA ENGINEERS, INC.
APPENDIX C
Standard Grading Specifications
BUENA ENGINEERS, INC.
C-1
STANDARD 6RADiN6 SPECIFICATIONS
PROJECT: JOHNSON OFFICE BUILDIN6
CLIENT: WARREN JOHNSON
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 area 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 wag 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.
BUENA ENGINEERS, INC.
C-2
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 negotiations for "changed or differing site conditions" can proceed.
If the owner determines that conditions do materially so differ and
cause an increase or decrease in the 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 densities of compaction
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. There sheepsfoot rollers are
used, the soil may be disturbed to a 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_
BUENA ENGINEERS, INC.
' 10. Earth -moving and working operations shall be controlled to prevent
water from running into excavated areas. Excess water shall be
promptly removed and the site kept dry. Fill material shall not be
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 mare 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 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 fill 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
I
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.
11
BUENA ENGINEERS, INC.
' 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, water shall be added until the soils attain
' a moisture content so that thorough bonding is achieved 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.
1 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.
1
IBUENA ENGINEERS, INC.
i
' 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 in the
' trench according to the applicable portions of these grading
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 a 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
I
foundations should not be placed over the capped well
7
L
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i I
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I I
I I
I I
' BUENA ENGINEERS, INC.