HomeMy WebLinkAboutGeotechReportRoughGrading(Mar.2,2002)
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e PETRA
COSTA MESA . SAN DIEGO . TEMECULA . LOS ANGELES
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March 27, 2002
J.N.241-01
PACIFIC CENTURY HOMES
40925 County Center Drive, Suite 110
Temecula, California 92591
Attention: Mr. Dave Parker
Subject: Geotechnical Report of Rongh Grading, Park F and Old Kent Road,
Tract 23143-5, City of Temecula, Riverside County, California
This report provides a summary of the observation and testing services provided by
Petra Geotechnical, Inc. (Petra) during rough-grading operations for Park F and Old
Kent Road within Tract 23143-5 located in the City of Temecula, California. Park F
and Old Kent Road are located on the eastern margin of the Crowne Hill
Development. Conclusions and recommendations pertaining to the suitability of the
grading for the proposed park and roadway are provided herein, as well as foundation
design-recommendations based on the as-graded soil conditions.
The purpose ofthis phase of rough grading was to develop a relatively level park site,
to prepare the park site for the construction of the proposed facilities and sidewalks,
and to construct Old Kent Road. The proposed park facilities will consist of a parking
lot, tot lots, open space and sidewalks. Grading was performed from February through
March 2002.
REGULATORY COMPLIANCE
The removal and recompaction oflow-density surface soils, processing of the exposed
bottom surfaces and placement of compacted fill under the purview of this report have
been completed under the observation of and with selective testing by Petra.
Earthwork and grading were performed in accordance with Petra's recommendations
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PETRA GEOTECHNICAL, INC.
27620 Commerce Center Drive. Suite 103 . Temecula . CA 92590 . Tel: (909) 699~6193 . Fax: (909) 699-6197 . petrate@ibm,net
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
IN. 241-01
Page 2
presented in our geotechnical investigation reports (see References) and in accordance
with the Grading Code of the City of Temecula, California.
The completed earthwork has been reviewed and is considered adequate for the
construction now planned. On the basis of our observations during rough grading and
field and laboratory testing, the recommendations presented in this report were
prepared in conformance with generally accepted professional engineering practices
and no further warranty is implied nor made.
ENGINEERING GEOLOGY
General
Geologic conditions exposed during the process of grading were frequently observed
and mapped by Petra's geologic staff.
Geologic Units
Earth materials within the site include topsoil, alluvium, and Pauba Formation
sandstone. The topsoil mantle at the site consisted of medium brown to dark brown
silty sand, sandy silt or clayey silt and was generally loose and soft.
The underlying alluvium consisted of light brown to dark brown silty sand, clayey
sand or well-graded sands. These materials were generally dry to moist and firm
(medium dense) to stiff(dense). Quaternary Pauba Formation bedrock underlies the
alluvium at the park site and consisted of grey to yellow brown massively bedded
clayey sandstone and silty sandstone. Pauba Formation bedrock was exposed beneath
the western edge of the park site and the majority of Old Kent Road.
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent RdlTemecula
March 27, 2002
J.N.241-01
Page 3
Groundwater
No groundwater was encountered during rough-grading operations.
Faulting
No faults were encountered during grading operations on the site.
SUMMARY OF EARTHWORK
OBSERVATIONS AND DENSITY TESTING
Clearing and Grubbing
Prior to grading, all weeds, grasses, brush and shrubs were removed from the site.
Clearing operations included the removal of all trash, debris and similar unsuitable
material.
Ground Preparation
Remedial grading for Park F within the landscape areas involved removal of low-
density topsoils to a depth of 2 feet below the original ground surface.
Remedial grading beneath the parking-lot area of the park site, the restroom area, Old
Kent Road and structural areas within Park F was accomplished to depths of
approximately 8 feet below the original ground surface. The base of the
overexcavations exposed Pauba Formation bedrock or dense alluvial soils.
Fill Slopes
Fill slopes around the perimeter of the park site and along Old Kent Road were
constructed at a 2: I (horizontal:vertical [h:v]) slope ratio to a maximum height of 30
feet..
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.241-01
Page 4
Cut Slopes
Cut slopes were not constructed within the boundaries of the park site. Minor cut
slopes were constructed north of Old Kent Road at a 2: I (h:v) slope ratio to a
maximum height of 5 feet.
Fill Placement and Testing
Fill materials placed on the park site and Old Kent Road consisted of onsite-derived
soils. All fills were placed in lifts restricted to approximately 6 to 8 inches in
maximum thickness, watered or air-dried as necessary to achieve a moisture content
equal to or slightly above or under optimum moisture content. Fill materials were then
compacted in-place to a minimum relative compaction of 85 percent in landscape areas
and 90 percent in areas of proposed structures by wheel-rolling with an 824 rubber-
tired dozer or loaded scrapers. The approximate location of the structural fill soils is
shown on the accompanying geotechnical map (plate 2). The maximum vertical depth
of compacted fill placed within the park site as result of the grading is approximately
39 feet. In cut areas, the upper I foot was scarified, air-dried to an acceptable moisture
content and then recompacted in-place to a minimum relative compaction of 85
percent in landscape areas and 90 percent in areas of proposed structures.
Field density and moisture content tests were performed in accordance with nuclear-
gauge test methods (ASTM Test Methods D2922 and D3017) and the sandcone
method (ASTM Test Method DI556). Test results are presented on the attached
Table I and approximate field density-test locations are shown on the enclosed grading
plans (Plates I and 2).
Field density tests were taken at vertical intervals of approximately I to 2 feet. The
compacted fills were tested at the time of placement to verifY that the specified
moisture content and minimum-required relative compaction of85 or 90 percent had
been achieved. At least one in-place density test was taken for each 1,000 cubic yards
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.24I-Ol
Page 5
of fill placed and/or for each 2 feet in vertical height of compacted fill. The actual
number oftests taken per day varied with the project conditions, such as the number
of earthmovers (scrapers) and availability of support equipment.
Visual classification of earth materials in the field was the basis for determining which
maximum dry density value was applicable for a given density test and are
summarized in Appendix A. One-point checks were performed to supplement visual
classification.
LABORATORY TESTING
Maximum Dry Density
Maximum dry density and optimum moisture content for each change in soil type were
determined in Petra's laboratory in accordance with Test Method ASTM D1557.
Applicable test results are presented in the attached Table 1.
Expansion Index Tests
An expansion index test was performed on a representative sample of soil existing at
or near finish-pad grade within the park. The test was performed in general
accordance with ASTM Test Method 04829. Soils were found to have a LOW
expansion potential. The test result is summarized in Appendix A.
Soluble Sulfate Analyses
A water-soluble sulfate content was determined for a representative sample of soil
existing at or near pad grade within the park site in general accordance with California
Test Method No. 417. The test result indicated a NEGLIGIBLE sulfate content ofless
than 0.1 percent and is summarized in Appendix A.
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.241-0l
Page 6
FOUNDATION-DESIGN RECOMMENDATIONS
Allowable-Bering Capacities
An allowable-bearing value of 1,500 pounds per square foot (pst), including both dead
and live loads, may be used for 12-inch wide continuous footings founded at a
minimum depth of 12 inches below the lowest adjacent final grade. This value may
be increased by 20 percent for each additional foot of width or depth, to a maximum
value of2,500 psf. Recommended allowable-bearing values include both dead and
live loads and may be increased by one-third for short-duration wind and seismic
forces.
Lateral Resistance
A passive earth pressure of250 pounds per square foot per foot of depth may be used
to determine lateral-bearing resistance for footings. In addition, a coefticient of
friction of 0.35 times the dead-load forces may be used between concrete and the
compacted-fill soils to determine lateral-sliding resistance. An increase of one-third
of the above values may also be used when designing for short-duration wind or
seismic forces. The above values are based on footings placed directly against
compacted fill or competent bedrock materials. In the case where footing sides are
formed, all backfill placed against footings should be compacted to a minimum of90
percent of maximum dry density.
Footing Observations
All building-footing trenches for the proposed structures should be founded into
compacted fill materials and be observed by the project geotechnical consultant to
verifY that they have been excavated into competent bearing soils prior to placement
of forms, reinforcement or concrete. All loose, sloughed or moisture-softened soil
should be removed prior to concrete placement. Excavated materials from utility and
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.24l-01
Page 7
footing excavations should not be placed in slab-on-ground areas unless properly
compacted and tested.
Soluble Sulfates Analysis
Results of the laboratory tests performed in accordance with California Test Method
No. 417 indicate onsite soils contain water-soluble sulfate contents ofless than 0.1
percent. Therefore, according to 1997 Uniform Building Code (UBe) Table 19-A-3,
a negligible exposure to sulfate can be expected and the use of Type I Portland cement
concrete placed in contact with the onsite soils is acceptable.
Expansive Soil Considerations
Results of a laboratory test performed on a representative sample of the onsite soils
indicate that the foundation soils existing within the subject sight exhibit an expansion
potential of LOW as classified in accordance with 1997 UBC Table 18-I-B. Based
on these soil conditions, it is recommended that footings and floors be sized and
reinforced in accordance with the following minimum criteria. However, additional
slab thickness, footing sizes and/or reinforcement should be provided as required by
the project architect or structural engineer.
Low Expansion Potential (Expansion Index of 21 to SOl
The following recommendations pertain to foundation soils exhibiting a LOW
expansion potential as classified in accordance with 1997 UBC Table 18-I-B. The
1997 UBC specifies that slab-on-ground foundations (floor slabs) on soils with an
expansion index greater than 20 require special design considerations in accordance
with 1997 UBC Section 1815. The design procedures outlined in 1997 UBC Section
1815 are based on the thickness and plasticity index of each different soil type
existing within the upper 15 feet of the building site. Based on subsurface
stratigraphy and distribution of the different soil types, we have calculated an
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27,2002
J.N.24l-0l
Page 8
effective plasticity index of 12 in accordance with 1997 UBC Section 1815.4.2.
Based on this soil condition, it is recommended that footings and floors be
constructed and reinforced in accordance with the following minimum criteria.
However, additional slab thickness, footing sizes and/or reinforcement should be
provided as required by the project architect or structural engineer.
. Footings
- Exterior continuous footings may be founded at the minimum depths indicated
in 1997 UBC Table 18-I-C (i.e., 12-inch minimum depth for one-story and 18-
inch minimum depth for two-story construction). Interior continuous footings
for both one- and two-story construction may be founded at a minimum depth
of 12 inches below the lowest adjacent grade. All continuous footings should
have a minimum width of 12 and 15 inches, for one- and two-story buildings,
respectively and should be reinforced with two NO.4 bars, one top and one
bottom.
- Exterior pad footings intended for the support of roof overhangs, such as
second-story decks, patio covers and similar construction, should be a
minimum of 24 inches square and founded at a minimum depth of 18 inches
below the lowest adjacent final grade. The pad footings should be reinforced
with No.4 bars spaced a maximum of 18 inches on centers, both ways, near
the bottom-third of the footings.
. Floor Slabs
- The project architect or structural engineer should evaluate minimum floor-
slab thickness and reinforcement in accordance with 1997 UBC Section 1815
based on an effective plasticity index of 12. Unless a more stringent design
is recommended by the architect or the structural engineer, we recommend a
minimum slab thickness of 4 inches for both living-area and garage-floor slabs
and reinforcing consisting of either 6-inch by 6-inch, No.6 by No.6 welded-
wire mesh (6x6-W2.9xW2.9) or No.3 bars spaced a maximum of 18 inches
on centers, both ways. All slab reinforcement should be supported on
concrete chairs or bricks to ensure the desired placement near mid-height.
- Moisture sensitive concrete-floor slabs should be underlain with a moisture-
vapor barrier consisting of a polyvinyl chloride membrane, such as 6-mil
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.241-0l
Page 9
Vis queen or equivalent. All laps within the membrane should be sealed and
at least 2 inches of clean sand be placed over the membrane to promote
uniform curing of the concrete.
- Prior to placing concrete, the subgrade soils below all floor slabs should be
pre-watered to achieve a moisture content that is at least equal to or slightly
greater than optimum-moisture content. This moisture content should
penetrate to a minimum depth of 12 inches into the subgrade soils.
Retaining Walls
Footing Embedments
The base of retaining-wall footings constructed on level ground may be founded at a
minimum depth of 12 inches below the lowest adjacent final grade. Where retaining
walls are proposed on or within 15 feet from the top of any adjacent descending fill
slope, the footings should be deepened such that a minimum horizontal clearance of
Hl3 (one-third the slope height) is maintained between the outside bottom edges of the
footings and the face of the slope but need not exceed 12 feet. This horizontal
structural setback may be reduced to 10 feet where footings are constructed near the
tops of descending cut slopes.
All footing trenches should be observed by the project geotechnical consultant to
verify that the footing trenches have been excavated into competent-bearing soils
and/or bedrock and to the minimum embedments recommended above. These
observations should be performed prior to placing forms or reinforcing steel.
Active and At-Rest Earth Pressures
An active lateral earth pressure equivalent to a fluid having a density of35 pounds per
cubic foot (pet) is tentatively recommended for design of cantilevered walls retaining
a level backfill. Where the wall backfill slopes upward at 2: I (h:v), the above value
should be increased to 53 pcf.
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent RdlTemecula
March 27, 2002
IN. 241-01
Page 10
For walls that are restrained at the top, at-rest earth pressures of 53 and 78 pcf
(equivalent fluid pressures) should be used for walls supporting a level backfill and
ascending 2: I (h:v) backfill, respectively.
The above active and at-rest lateral earth pressures are based on a well-drained
backfill. All walls should also be designed to support any adjacent structural
surcharge loads imposed by other nearby walls or footings in addition to the above
active and at-rest earth pressures.
Drainage and Moisture Proofing
All retaining walls should be provided with perforated pipe-and-gravel subdrains to
prevent entrapment of water in the backfill. Perforated pipe should consist of 4-inch
minimum diameter PVC Schedule 40 or ASS SDR-35, with the perforations laid
down. The pipe should be embedded in 1.5 cubic feet per foot of 0.75- or 1.5-inch
open-graded gravel wrapped in filter fabric. Filter fabric may consist ofMirafi l40N
or equal. The gravel should be at least I-foot wide and extend to a minimum height
of 1.5 feet above the footing. A solid outlet pipe should be connected to the perforated
pipe and then routed to a suitable area for discharge of accumulated water. These
portions of the walls supporting backfill should also be coated with an approved
waterproofing compound or covered with such material to inhibit infiltration of
moisture through the walls.
Wall Backfill
All wall backfill should be placed in 6- to 8-inch-maximum lifts, watered or air-dried
as necessary to achieve near optimum moisture conditions and compacted in place to
a minimum relative compaction of 90 percent. Flooding or jetting should not be
permitted. Probing and testing should be performed by the geotechnical consultant or
his representative to verify the relative compaction of wall backfill.
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27,2002
J.N.24l-01
Page II
Temporary Excavations
To accommodate retaining-wall construction, temporary slopes may be cut vertical,
provided the vertical cut does not exceed a height of 5 feet. Where the vertical cut
exceeds this height, the upper portions above a height of 5 feet should be cut-back at
a maximum gradient of I: 1 (horizontal:vertical) for the duration of construction.
Temporary slopes constructed at the above configurations are expected to remain
stable during construction of retaining walls; however, all temporary excavations
should be observed by the geotechnical consultant for any evidence of potential
instability. Depending on the results of these observations, flatter slopes may be
necessary .
Masonry Garden Walls
Construction on or Near the Tops of Descendinl: Slopes
Continuous footings for masonry garden walls proposed on or within 7 feet from the
top of any descending cut or fill slope should be deepened such that a minimum
horizontal clearance of 5 feet is maintained between the outside bottom edge of the
footing and the slope face. The footings should be reinforced with a minimum of two
No.4 bars, one top and one bottom. Plans for any top-of-slope garden walls proposing
pier and grade-beam footings should be reviewed by the project geotechnical
consultant prior to construction.
Construction on Level Ground
Where masonry walls are proposed on level ground and at least 7 feet from the tops
of descending slopes, the footings for these walls may be founded at a minimum depth
of 12 inches below the lowest adjacent final grade. These footings should also be
reinforced with a minimum of two No.4 bars, one top and one bottom.
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent RdlTemecula
March 27, 2002
J.N.241-0l
Page 12
Construction Joints
In order to mitigate the potential for unsightly cracking related to the effects of
differential settlement, positive separations (construction joints) should be provided
in the walls at horizontal intervals of approximately 25 feet and at each corner. The
separations should be provided in the blocks only and not extend through the footings.
The footings should be placed monolithically with continuous rebars to serve as
effective "grade beams" along the full lengths of the walls.
Pavement Design
Representative samples of the subgrade soils were obtained after completion of rough-
grading of the park site and Old Kent Road and tested for R-value in accordance with
the latest revisions of California Test Method No. 30 I. The following table presents
a summary of the laboratory R-value test results.
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I R-l I Park site I 66 I
R-2 Old Kent Road 44
A design traffic index of 5.0 for Old Kent Road was provided on plans by RBF
Consulting Engineers. The following pavement sections have been computed in
accordance with the State of California design procedures. The asphaltic-concrete
pavement design calculations are attached.
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent RdlTemecula
March 27, 2002
J.N.241-01
Page 13
r~fi15;~~;1~~~1~~~~~~
Old Kent Road
44
5.0
5.0
0.25 over 0.50
Park F roadways
66
44
0.25 over 0.50
Alternative section
5.0
0.35 over 0.35
Note:
AC - Asphaltic Concrete (feet)
AB - Aggregate Base (feet)
Subgrade soil immediately below the aggregate base (base) should be compacted to
a minimum of95 percent relative compaction based on ASTM Test Method D1557
to a minimum depth of 12 inches. Final subgrade compaction should be performed
prior to placing base or asphaltic concrete and after all utility-trench backfills have
been compacted and tested.
Base materials should consist of Class 2 aggregate base conforming to
Section 26-1.02B of the State of California Standard Specifications or crushed
aggregate base conforming to Section 200-2 ofthe Standard Specifications for Public
Works Construction (Greenbook). Base materials should be compacted to a minimum
of 95 percent relative compaction based on ASTM Test Method D1557. The base
materials should be at or slightly below optimum moisture content when compacted.
Asphaltic-concrete materials and construction should conform to Section 203 of the
Greenbook.
Concrete Flatwork
Thickness and Joint Spacinlr
Concrete sidewalks, patio-type slabs and concrete subslabs to be covered with
decorative pavers should be at least 3.5 inches thick and provided with construction
joints or expansion joints every 6 feet or less. Concrete-driveway slabs should be at
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.241-01
Page 14
least 4 inches thick and provided with construction joints or expansion joints every 10
feet or less.
Subgrade Preparation
As a further measure to minimize cracking of concrete flatwork, the subgrade soils
should first be moisture conditioned to achieve a moisture content that is at least equal
to or slightly greater than optimum moisture content and then compacted to a
minimum relative compaction of 90 percent. The moisture should extend to a depth
of 12 inches below subgrade and be maintained in the soils during placement of
concrete. Pre-watering of the soils will promote uniform curing of the concrete and
minimize the development of shrinkage cracks. The project geotechnical consultant
should observe and verify the density and moisture content of the soils and the depth
of moisture penetration prior to placing concrete.
Drainage
Drainage from flatwork areas should be directed to local area drains and/or graded-
earth swales designed to carry runoff water to the adjacent streets or other approved
drainage structure. The concrete flatwork should also be sloped at a minimum
gradient of I percent away from building foundations, retaining walls, masonry garden
walls and slope areas.
Planters
Area drains should be extended into all planters that are located within 5 feet of
building walls, foundations, retaining walls and masonry-block garden walls to
minimize excessive infiltration of water into the adjacent foundation soils. The
surface of the ground in these areas should also be sloped at a minimum gradient of
2 percent away from the walls and foundations. Drip-irrigation systems are also
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.24l-0l
Page 15
recommended to prevent overwatering and subsequent saturation of the adjacent
foundation soils.
POST-GRADING OBSERVATIONS AND TESTING
Petra should be notified at the appropriate times in order that we may provide the
following observation and testing services during the various phases of post-grading
construction.
. Building Construction
- Observe all footing trenches when first excavated to verifY depth and competent
soil-bearing conditions.
- Re-observe all footing trenches, if necessary, if trenches are found to be
excavated to inadequate depth and/or found to contain significant slough,
saturated or compressible soils.
. Retaining-Wall Construction
Observe all footing trenches when first excavated to verifY depth and competent
soil-bearing conditions.
Re-observe all footing trenches, if necessary, if trenches are found to be
excavated to inadequate depth and/or found to contain significant slough,
saturated or compressible soils.
- Observe and verify proper installation of subdrainage systems prior to placing
wall backfill.
- Observe and test placement of all wall backfill.
. Masonry Garden Walls
- Observe all footing trenches when first excavated to verifY depth and competent
soil-bearing conditions.
- Re-observe all footing trenches following removal of any slough and/or
saturated soils and re-excavation to proper depth.
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PACIFIC CENTURY HOMES
TR 23143-5 Park F & Old Kent Rd/Temecula
March 27, 2002
J.N.24l-01
Page 16
. Exterior Concrete Flatwork
- Observe and test subgrade soils below all concrete flatwork areas to verifY
adequate compaction and moisture content.
. Utility-Trench Backfill
- Observe and test placement of all utility trench backfill.
. Re-Grading
- Observe and test placement of any fill to be placed above or beyond the grades
shown on the grading plan.
This report is subject to review by the controlling authorities for this project.
We appreciate this opportunity to be of service. If you have any questions, please
contact this office.
Respectfully submitted,
CEG 1348
SMP/MB/keb/kms
Attachments: Table I - Field Density Test Results
References
Plates 1 and 2 - Geotechnical Maps with Density Test Location Maps
(in pocket)
Appendix A - Laboratory Test Criteria/Laboratory Test Data
Distribution: (6) Addressee
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REFERENCES
o PETRA
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REFERENCES
Petra Geotechnical, Inc., 2001a, Geotechnical Investigation of Tracts 23142 and 26941 and Preliminary Sewage-
Disposal Feasibility Evaluation ofCrowne Hill Estate Lots, Tract 26941, City ofTernecula, Riverside County,
California, J.N. 241-01, dated June 4, 200!.
,200Ib, Geotechnical Review of Rough-Grading Plans for Tracts 23143-1, 23143-6 through 23143-11,
23143-F, Crown Hill Park Site (Tract 23145-5) and Park Site 'A' (Lot 104 of Tract 23143-F), City of
Ternecula, Riverside County, California, J.N. 241-01, dated October 31, 200!.
, 2001c, Settlement Characteristics of Fill Soils for Tract 23143, City of Ternecula, Riverside County,
California, J.N. 241-01, dated December 10, 200!.
, 2001d, Reliance Letter for Tracts 23143-1, 23143-6 through 23143-11, 23143-F, Crowne Hill Park Site
(Tract 23145-5) an d Park Site "A" (Lot 104 of Tract 23l43-F), City of Ternecula, Riverside County,
California;for Lowe Enterprises Residential Advisors, J.N. 241-01, dated December II, 200!.
,2002, Geotechnical Recommendations for Removal Depths, Park Site A within Tract 23143-F and Park Site F
within Tract 23143-5, City ofTernecula, Riverside County, California, IN. 241-01, dated January 24, 2002.
PETRA GEOTECHNICAL, INC.
I.N. 241-01
MARCH 2002
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APPENDIX A
LABORATORY TEST CRITERIA
LABORATORY TEST DATA
o PETRA
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APPENDIX A
LABORATORY TEST CRITERIA
Laboratory Maximum Dry Densitv
Maximum dry density and optimum moisture content were determined for selected samples of soil and bedrock
materials in accordance with ASTM Test Method D1557. Pertinent test values are given on Plate A-I.
Exnansion Potential
Expansion index tests were performed on selected samples of soil and bedrock materials in accordance with ASTM
Test Method D4829. Expansion potential classifications were determined from 1997 UBC Table 18-I-B on the basis
of the expansion index values. Test results and expansion potentials are presented on Plate A-I.
Soluble Sulfate
Chemical analysis was performed on a selected sample of onsite soil to determine concentrations .of soluble sulfate.
This test was performed in accordance with California Test Method No. 417. The test result is included on Plate A-I.
PETRA GEOTECHNICAL, INC.
J.N.241-01
MARCH 2002
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LABORATORY MAXIMUM DRY DENSITY'
~, -T(5:;;;fi;',;~:--T- fi~~- - ,
f;l>~ III S:m1'l\-w I ~\'i~ :')]m ""
~~ ------.J~&.. J~
Medium brown Silty fine to medium SAND 8.5 129.0
2 Light brown Clayey Silty fine to coarse SAND 8.5 132.0
3 Yellowish brown Silty fine to coarse SAND 9.0 128.0
4 Olive brown Clayey Silty fine to medium SAND 9.0 130.5
5 Tan to yellow Sandy SILT 9.0 129.0
6 Tan Silty fine SAND 12.0 125.0
7 Light brown Silty fine to coarse SAND 9.5 127.0
8 Tan Silty medium to coarse SAND with trace Gravel 10.5 126.0
9 Brown Sil fine to medium SAND 10.5 128.0
EXPANSION INDEX TEST DATA
Park site
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Low
SOLUBLE SULFATE
11~~1~1___11
,_ . E'Q!;a,ti9.!l_ . '. '- . . _ . ~Sltlf:lte'. .. . . . .
I Park site I 0.015 I
(I) PER ASTM TEST METHOD 01557
(2) PER ASTM TEST METHOD 04829
(3) PER ]997 UBC TABLE IS-I-B
(4) PER CALIFORNIA TEST METHOD NO. 4t7
PETRA GEOTECHNICAL, INC.
J.N. 241-01
MARCH 2002
PLATE A-l
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