HomeMy WebLinkAboutCT 82-23; Tentative Development CT 82-23; Soils Report; 1983-05-25-.
ENGlNEERlNQ DEPT, LIBRARY City of Carlsbad 2075 Las Palmas Drive Carisbad, CA 92009-4859
BOG 3J-2 2.W.ze)
GEOTECHNICAL INVESTIGATION
FOR
TENTATIVE PLANNED DEVELOPMENT, 82-23
CARLSBAD, CALIFORNIA
For
MOLA DEVELOPMENT CORPORATION
Huntington Beach, California
CEOCON, INCORPORATED
San Diego, California
May, 1983
GEOCON rn
TI
,1501,011100 -1 u
Geotechnical Engineers and Engineering Geologists
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File No. 0-2904-501 - May 25, 1983
Mola Development Corporation
Huntington Beach, California 92648
808 Adams
Attention: Mr. Ed Wale
Subject : TENTATIVE PLANNED DEVELOPMENT
MAP 82-23
CARLSBAD, CALIFORNIA
REPORT OF GEOTECHNICAL INVESTIGATION
Gentlemen:
In accordance with your authorization, we have performed a geotechnical
investigation for the subject project. The accompanying report presents
the findings from our study and our recommendations pertaining to the
geotechnical engineering aspects of project development.
Should you have any questions concerning the contents of this report or if
we may be of further service, please contact us at your convenience.
Very truly yours,
GEOCON, INCORPORATED
James E. Likins
RCE 17030
SRP:JEL:ln
(6) addressee
Michael W. Hart
CEG 706
Steven R. Penn
RS 4007
9530 Dowdy Drive San Diego. CA 92126 619 6952880
"1,. .....
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- '? i TABLE OF CONTENTS
Page
SOIL INVESTIGATION AND GEOLOGIC RECONNAISSANCE
Purpose and Scope. ..................... 1
Site and Project Description ................
3
1
Groundwater.........................
Soil Conditions
5
Geologic Hazards/Seismicity. ................ 5
CONCLUSIONS AND RECObPlENDATIONS. ................ 7
General. .......................... 7
Grading. .......................... 8
Foundations......................... 9
Concrete Slabs-on-Grade. .................. 10
Retaining Walls and Lateral Loads. ............. 10
Site Drainage and Moisture Protection. ........... 11
Grading and Foundation Plan Review ............. 11
LIMITATIONS AND UNIFORMITY OF CONDITIONS ............ 12
Figure 1, Site Plan. ...................... 13
APPENDIX A
......................
FIELD INVESTIGATION
Figures A-3 - A-7, Logs of Test Trenches
Figures A-1 - A-2, Logs of Test Borings
APPENDIX B
LABORATORY TESTING
Table I, Moisture-Density and Direct Shear Test Results
Table 11, Compaction Test Results
Table 111, Expansion Index Test Results
APPENDIX C
Recommended Grading Specifications
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File No. D-2904-J01
May 25, 1983
GEOTECHNICAL INVESTIGATION
Purpose and Scope
We have performed a geotechnical investigation for the Tentative Planned
Development Map 82-23 located in Carlsbad, California. The purpose of our
investigation was to evaluate the surface and subsurface soil and geologic
conditions at the site and, based on the conditions encountered, to provide
recommendations relative to the geotechnical engineering aspects of project
development.
The scope of our field investigation consisted of a site reconnaissance,
the drilling of two exploratory borings and the excavation of seven
exploratory trenches. In addition, a review of relevent soil and geologic
literature concerning the site was performed. Laboratory tests were
performed on selected representative soil samples to evaluate pertinent
physical properties. The recommendations presented herein are.based on an
analysis of the data obtained in the various phases of our investigation
and our experience with similar soil and geologic conditions.
Site and Project Description
The site is a 17.77+ - acre parcel which is situated on the vest side of El
Camino Real north of Alga Road in Carlsbad, California. The parcel contains
approximately 783+ - feet of frontage along El Camino Real and approximately
1063 feet along Alga Road. Topographically, the parcel is divided into
western and eastern portions by a north- to south-trending, well defined
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File No. D-2904-301
"I natural drainage course. At the time of our investigation, there was a
- small amount of water flowing in this drainage course.
- The western portion of the parcel ranges in elevation from a high point of
225 feet MSL along the western property line to a low of 110 feet MSL in
the bottom of the drainage swale as it exits the site to the south. The
eastern portion of the site ranges from a high point of 195 feet MSL in the
northwest corner of the parcel to a low point of 160 feet MSL in the bottom
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_. of the central drainage channel/ravine at the north property line.
- The preliminary grading plan for the project prepared by Sowards Engineer-
ing dated November 8, 1982 was utilized as a guide in the investigation.
- In general, development plans call for a balanced grading operation, with
cuts of 10 to 20 feet on the west and east slopes, and filling of the
north- to-south-trending central ravine. The maximum depth of fill soils
will be approximately 45 feet at the south-central portion of the site.
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The plans indicate that the eastern portion~of the site will be a shopping/
commercial center and the western portion will be residential. , The
commercial site will consist of five buildings with associated parking and
roadway areas. We snticipate that the tuildings will be one- and/or two-
-
- story structures and that the small buildings will be of wood-frame
construction and that the larger buildings will be of concrete tilt-up
construction. We also anticipate that spread and/or continuous footings
with slab-on-grade floors will be utilized. The residential complex
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proposed for the western part of the site will consist of 10 one- and/or
two-story multi-plex structures and associated parking and driveway areas.
We anticipate that construction will be of wood-frame and stucco with
spread and/or continous footings and slab on-grade floors. Should project
details vary significantly from those outlined, Geocon, Incorporated should
be notified for review and possible revision of the recommendations
-
-
presented herein.
Soil Conditions
As indicated by the exploratory borings and our review of relevant liter-
ature, the site is generally underlain by Eocene-aged Torrey sandstone. In
Boring 2 at a depth of approximately 12 to 13 feet, corresponding to a mean
sea level elevation of approximately 156 feet, sandstones and claystones of
the Delmar Formation were encountered. The Torrey sandstone consisted of
moderately dense to very dense, white to yellow-tan, lightly to highly
cemented, fine to medium sand. The Delmar Formation consisted of moderately
dense to dense, greenish-gray to greenish-brown, clayey sands to very waxy
claystone. The Torrey sandstone is expected to be the predominant soil
type exposed at finish grade over the majority of the site at the comple-
tion of grading. This material in either a natural or recompacted state
should exhibit excellent foundation support characteristics with minimal
postconstruction settlement or expansion potential. The Delmar Formation
encountered in Boring 2 is highly expansive and, therefore, is not suitable
as a foundation bearing material. Based upon the depth of the Delmar
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File NO. D-2904-J01
May 25, 1983
Formation in relationship to the anticipated grading, it appears that very
little of this material will be exposed at finish grade. If encountered
within 2 feet of finish grade, the affected area can be overexcavated 2
feet and capped with suitable material utilized to cap the pad.
Overlying the formational soils in most areas of the site is a 1- to
3-foot-thick topsoil layer consisting of moderately to highly expansive
clayey silty sands to sandy clays. This material is not suitable for use
in capping pads but can be utilized in the bottom of the deeper fills in
the central portion of the site.
Saturated, loose and unconsolidated alluvial deposits were encountered
within the confines of the well defined, deeply incised north- to south-
trending drainage basin and, to a lesser extent, within the immediate
vicinity of the small tributary drainage swales. As indicated by the logs
of the exploratory trenches, the depth of the alluvium in the smaller
drainage swales is 2 to 8 feet. The loose. and saturated condition of the
sands encountered in the bottom of the large central drainage feature made
exavation very difficult. In all of these trenches it was determined that
the depth of the alluvial deposits were greater than the excavation depth
of the backhoe. Based upon pertinent literature and our experience with
similar sites, an alluvial depth fo 15 to 20 feet should be anticipated.
-
As the horizontal extent of the alluvium is limited by the well defined and
deeply incised drainage swale, the total volume of alluvium should be
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File No. D-2904-J01
May 25, 1983
within acceptable limits. However, the saturated condition of these
materials may hamper removal efforts. It will, however, be necessary to
remove all loose alluvial deposits until firm natural soils are exposed
prior to the placement of any fill soils.
Groundwater
Free groundwater was not encountered in the deep exploratory Borings 1 and
2 or the deep exploratory Trench 8. As mentioned previously, flowing
surface water was present at the time of our investigation in the large
drainage swale and a number of the smaller tributaries. This surface flow
of water did result in the saturation of the alluvial soils in these areas
with resultant groundwater infiltration into the excavated trenches.
However, it is our opinion that this water is transitory and
nature, and that water fron actual local water tables will
surface in
not affect
project development as presently proposed.
Geologic HazardsISeismicity
It is our opinion, based on our site reconnaissance, evidence obtained in
the exploratory borings and a review of published geologic maps and
reports, that the site is not located on any known fault trace. The
nearest known active faults are the Elsinore and San Jacinto Fault systems
which lie approximately 27 and 49 miles to the northeast, respectively. A
review of Special Report No. 123 (California Division of Mines and Geology)
indicates the most northernly mapped location of the potentially active
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May 25, 1983
-,
Rose Canyon Fault lies approximately 7 miles to the southwest. It is our
- opinion that the site could be subjected to moderate to severe ground
shaking in the event of a major earthquake along any of the above mentioned
faults. However, the seismic risk at the site is not significantly greater
than that of the surrounding area.
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I May 25, 1983
CONCLUSIONS AND RECOMMENDATIONS
General
1. It is our opinion no adverse soil or geologic conditions are present on
the site which would preclude the development of the proposed commercial/
residential project as described herein, provided the recommendations of
this report are followed.
2. The site was found to be covered by a thin (approximately 1- to 3-fOOt)
mantle of topsoil consisting of relatively loose, moderately to highly
expansive, clayey sands and sandy clays on the western and eastern slopes.
Underlying the topsoils are sands' of the Torrey Sandstone Formation.
Underlying the Torrey Sandstone, in the southeast corner of the site in the
vicinity of Boring 2, are clayey sands and claystones of the Delmar
Formation. Loose, unconsolidated, saturated alluvium was encountered
within the well defined confines of the large north-south-trending drainage
swale bisecting the site and, to a lesser extent, is the center of many of
the smaller drainage tributaries. These alluvial soils, in their present
condition, are not considered suitable for foundation support and will
require remedial grading prior to placement of fill.
3. Groundwater encountered in the drainage swales on the site is, in our
opinion, transitory and caused by surface runoff and drainage through the
site. The presence of this water, however, may increase the difficulty in
removing the loose alluvium in the drainage swales.
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May 25, 1983
4. No potential geologic hazards were observed or are known to exist on
the site which would adversely affect the proposed project.
Grading
5. All grading should be performed in accordance with the "Recommended
Grading Specifications" contained in Appendix C and the City of Carlsbad
Grading Specifications. Where the recommendations of Appendix C conflict
with this section of the report, the recommendations of this section take
precedence.
6. Site preparation should begin with removal of all deleterious matter
and vegetation.
7. Loose, saturated alluvial deposits should be excavated and removed from
all drainage swales until firm natural ground is exposed. The exposed
natural ground should then be scarified to a depth of 12 inches, moisture
conditioned and recompacted to at least 90 percent of maximum dry density
as determined in accordance with ASTM Test 'Procedure D1557-70, Method A or
C.
8. Fill soils derived from stockpiled alluvium, native topsoils and onsite
cutting operations can then be placed in compacted layers until final
elevations are reached.
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File No. D-2904-J01
Foundations
9. All pads should be capped with at least 24 inches of non- to low
expansive soils. Where cut-fill daylight lines cross building pads, the
pads should be overexcavated 24 inches and replaced with properly compacted
non- to low expansive soils. It is our opinion that cut and fill slopes
inclined at slopes of 2 horizontal to 1 vertical will possess a factor of
safety of 1.5 or greater for near-surface sloughage and deep-seated
rotational failure (static loading), provided that the site is graded as
- recommended herein.
10. Fill slopes should be backrolled at intervals of at least 4 feet
and/or trackwalked, grid rolled or otherwise compacted such that relative
compactions of at least 90 percent are obtained within the top 12 inches of
the slope face.
11. It is recommended that minimum footing reinforcement consist of two
continuous No. 4 steel reinforcing bars placed horizontally in the foot-
ings, one near the top of the footing and one near the bottom. The above
minimum reinforcement is based on soil characteristics and is not intended
to be in lieu of reinforcement necessary for structural considerations.
12. An allowable bearing capacity of 2000 psf may be used for foundations
constructed as recommended above. The allowable bearing capacity is for
dead plus live loads and may be increased by one-third for transient loads
due to wind or seismic forces.
.
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13. It is estimated that .total and/or differential postconstruction
settlement for foundations designed as recommended herein will be within
normal tolerable limits for the proposed structures (less than 0.5-inch).
Concrete Slabs-on-Grade
14. Concrete slabs should have a nominal thickness of 4 inches and be
underlain by at least 4 inches of clean sand. Minimum reinforcement should
consist of 6x6-10/10 welded wire mesh throughout. Care should be taken to
place mesh in the middle of the slab.
15. Granular base would tend to act as a capillary barrier to moisture but
will not provide a positive barrier against the rise of moisture through
slabs. If moisture sensitive floor coverings are involved in any part of
the structures, an impervious membrane vapor barrier should be utilized.
Where used, a 2-inch layer of clean sand should be placed between the base
of the slab and the membrane to minimize shrinkage cracking and allow
proper curing of the concrete.
Retaining Walls and Lateral Loads
16. Lateral loads may be resisted by "passive" earth pressures. Passive
earth pressures against shallow spread-type or continuous wall footings in
contact with properly compacted backfill should be considered as being
equal to the forces exerted by a fluid of 300 pcf unit weight.
17. A coefficient of friction of 0.4 may be used between the bases of
footings and slabs and the soil for computing resistance to sliding.
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18. Retaining walls, which are not fixed at the top, should be designed to
- resist an active soil pressure of 30 pcf unit weight. Where the wall will
be fixed or restrained at the top, an additional uniform horizontal
pressure of 50 psf should be included. The values assume a drained and
level granular backfill condition. Waterproofing and wall drainage details
should be provided by the project architect.
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- Site Drainage and Moisture Protection
19. The provisions and maintenance of adequate site drainage and moisture -
protection of supporting soils is an important design consideration.
- Foundation recommendations presented herein assume proper site drainage
will be established and maintained.
-
20. Under no circumstances should water be allowed to pond adjacent to
footings. The site should be graded such that surface drainage flow is
directed away from structures and'into swales or other controlied drainage
facilities.
21. Landscaped areas within parking areas should be designed such that
excess irrigation water is positively drained. Ponding of water within
thsse areas could cause localized high moisture within subgrade soil
increasing the potential for pavenent failure and/or increased maintenance.
Grading and Foundation Plan Review
22. Geocon, Incorporated should review the final grading and foundation
plans to verify their compliance with this report.
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File No. D-2904-J01 L
.- - LIMITATIONS AND UNIFORMITY OF CONDITIONS
- 1. The recommendations of this report pertain only to the site investi-
gated and are based upon the assumption that the soil conditions do not
deviate from those disclosed in the investigation. If any variations or
undesirable conditions are encountered during construction, or if the
proposed construction will differ from that planned at the present time,
Geocon, Incorporared should be notified so that supplemental recom-
mendati0n.s can be given.
2. This report is issued with the understanding that it is the
responsibility of the owner, or of his representative, to ensure that the
information and recommendations contained herein are brought to the
attention of the architect and engineer for the project and incorporated
-
into the plans, and the necessary steps are taken to see that the
contractor and subcontractors carry out such recommendations in-the field.
3. The findings of this report are valid as of the present date. However,
changes in the conditions of a property can occur with the passage of time,
whether they be due to natural processes or the works of man on this or
adjacent properties. In addition, changes in applicable or appropriate
standards may occur, whether they result from legislation or the broadening
of knowledge. Accordingly, the 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 three
years.
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May 25, 1953 .I
..
0 .__.___PROPOSED STRUCTURE
SITE PLAN
TENTATIVE PLANNED DEVELOPHENT
YAP 32-23
CARLSBAD, CALIFORNIA
'IGURE 1 GEOCON INCORPORATED PAGE 13
File No. D-2904-JOl - May 25, 1983
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APPENDIX A
FIELD INVESTIGATION
_. 7'
The field investigation was performed between March 12 and May 11, 1983.
Inaccessability due to wet soil conditions hampered the completion of the
field portion of our investigation. The investigation consisted of the
excavation of two exploratory borings and eight exploratory trenches at the
approximate location shown on the Site Plan, Figure 1. The borings were
drilled to depths ranging from 21 to 26 feet below existing grade utilizing
a truck-mounted rotary drill rig equipped with 8-inch-diameter hollow stem
auger. The trenches were excavated using a Case 580 backhoe equipped with
a 24-inch-wide bucket.Chunk samples and bulk samples were obtained from the
backhoe excavations. For the exploratory borings, relatively undisturbed
samples were obtained by driving a 3-inch O.D. split-tube sampler into the
undisturbed soil mass with blows from a 140-pound hammer falling 30 inches.
The sampler was equipped with 1-inch by 2-3/8-inch brass sampler rings to
facilitare removal and testing.
During the investigaticn, the soils encountered were continuously examined,
visually classified and logged. Logs of the test borings and trenches are
presented on Figures A-1 through A-5 herein. The logs depict the depth and
description of the various soil types encountered and include the depths at
which sampling was performed.
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File No. D-2904-JOl -j May 25, 1983
APPENDIX B
LABORATORY TESTING
Laboratory tests were performed in accordance with generally accepted test
methods of the American Society for Testing and Materials (ASTM) or other
suggested procedures. Relatively undisturbed drive samples were tested for
their in-place dry density, moisture content, shear strength, compaction
and expansion potential characteristics. The results of these tests are
summarized in tabular and graphical form in Appendix B. In addition, in-
place moisture density relationships are presented on the logs of test
borings in Appendix A.
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File No. D-2904-J01
May 25, 1983 i -
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TABLE I
Summary of In-Place Moisture-Density and Direct Shear Test Results
Sample
NO.
1-1
1-2
*1"3
1-4
1-5
2-2
2-3
2-4
2-5
2-7
8-1
8-2
Dry
PCf
100.9
100.2
110.8
113.3
102.6
107.8
106.4
107.3
100.2
94.2
113.6
109.8
Density
Moisture
Content
%
11.8
10.7
11.1
8.1
10.2
9.3
11.6
18.2
23.8
25.3
8.0
9.7
Unit
Cohesion
psf
"-
"-
460
140 "_ "_
"-
50
"-
-I "_
1110
Angle of
Shear
Resistance
Degrees
"
"
27
52
"
"
"
52
"
"
"
45
*Sample remolded to approximately 90 percent of maximum dry density
at near optimum moisture content.
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TABLE I1
Summary of Laboratory Compaction Test Results
ASTM D1557-70
Sample
No. Description
1-3 Brown-tan, fine to medium,
slightly Clayey SAND
2- 1 Brown, Clayey Silty, fine
SAND
2-6 Green-tan, Silty Sandy CLAY
Maximum Dry
Density Moisture
Optimum
PCf % Dry Wt.
123.1 11.1
120.2 12.5
111.1 16.6
Sample
No.
2-1
2-6
TABLE 111
Summary of Laboratory Expansion Test Results
Moisture Content
Before Af fer
Expansion (+)
or
Test Test Dry Settlement(-)
Surcharge Density x % pcf % psf
12.9 25.2 108.4 + 8.5 150
16.0 30.8 100.8 +14.1 150
i File No. D-2904-JOl
- May 25, 1983
RECOMMENDED GRADING SPECIFICATIONS
1. General
1.1
-
1.2
-
1.3
-
2.
- 2.1
-
2.2
2.3 -
- 2.4
These specifications have been prepared for grading of the Tentative
Planned Development, Map 82-23 in Carlsbad, California. They shall
be used only in conjunction with the soil report for the project
dated May 25, 1983 prepared by Geocon, Incorporated.
The contractor shall be responsible for placing, spreading, watering,
and compacting the fill in strict conformance with these specifica-
tions. All excavation and fill placement should be done under the
observation of the Geocon, Incorporated. Geocon, Incorporated, should
be .consulted if the contractor or owner wishes to deviate from these
specifications.
The grading should consist of clearing, grubbing, and removing from
the site all material the Soil Engineer designates as "unsuitable";
materials; and all other work necessary to conform with the lines,
preparing areas to be filled; properly placing and compacting fill
grades, and slopes shown on the approved plans.
Preparation of Areas to be Graded
All trees and shrubs not to be used for landscaping, structures,
weeds, and rubbish should be removed from the site prior to
commencing any excavating or filling operations.
All buried structures (such as tanks, leach lines, and pipes) not
depressions should be properly backfilled and compacted prior to any
designated to remain on the site should be removed, and the resulting
grading or filling operations.
All water wells should be treated in accordance with the requirements
of the San Diega County Health Department. The owner shall verify the requirements.
All vegetation and soil designated as "unsuitable" by the Soil Engi-
neer should be removed under his observation. The exposed surface should then be plowed or scarified to a depth of at least 12 inches
until the surface is free from ruts, hummocks, or other uneven fea-
tures that would prevent uniform compaction by the equipment used.
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2.5 Where the slope ratio of the original ground is steeper than 6.0
horizontal to 1.0 vertical, or where recommended by the Soil Engi-
neer, the bank should be benched in accordance with the following
illustration.
NOTES
ilNlSEED SLCPE
SUEFACE (2) SLOUGHING OR SLIDING DOES NOT KCJR -
RWYE AS RECCMVENDED jY
S0I.L ENGINEER
(NOTE 2)
(NOTE I) -
2.6
- 3.
3.1
3.2
3.3
3.4
"B" should be 2 feet
wider than the com-
paction equipment,
and should be a min-
inum of 10 feet wide.
The outside of the
botton key should be
below the topsoil or
slopewash and at
least 3 feet into
dense formational ma-
terials.
After the areas have been plowed or scarified, the surface should be
disced or bladed until they are free from large clods; brought to the
specified in Section 4 of these specifications.
proper moisture content by adding water or aerating; and compacted as
Materials Suitable for Use in Compacted Fill
Material that is perishable, spongy, contains organic matter, or is
used for compacted fill should consist of at least 40 percent fines
otherwise unsuitable should not be used in compacted fill. Material
smaller than 314-inch diameter.
The soil engineer should decide what materials, either imported to
the site or excavated from on-site cut areas, are suitable for use in
Compacted fills; the Soil Engineer should approve any import material
before it is delivered to the site. During grading, the contractor
may encounter soil types other than those analyzed for the soil
investigation. The Soil Engineer should be consulted to evaluate the
suitability of such soils.
Any material containing rocks or hard lumps greater than 6 inches in
diameter should be placed in accordance with Section 6 of these
specifications.
The Soil Engineer should perform laboratory tests on representative
samples of material to be used in compacted fill. Such tests should
of the samples. The tests should be performed in accordance with
be perforned to evaluate the maximun dry density and moisture content
Materials (ASTM).
accepted test methods of the American Society of Testing and
- 4.2
4.3
-
4.4
4.5
-
4.6 -
4.7
5.
5.1
5.2
Placing, Spreading, and Compacting Fill Material
Unless otherwise specified, fill material should be compacted while
at a moisture content near the optimum moisture content and to a
relative compaction of at least 90 percent as determined by accepted
ASTM test methods.
Fill materials should be placed in layers that, when compacted, have
a relative compaction in conformance with the project specifications.
Each layer should be spread evenly and mixed thoroughly to provide
uniformity of materials in each layer.
When the moisture content of the fill material is less than that
reconmended by the Soil Engineer, water should be added until the
moisture content is as recommended. When the moisture content of the
fill material is more than that recommended by the Soil Engineer, the
fill material should be aerated by blading, mixing, or other methods
until the moisture content is as recommended.
After each layer is placed, nixed, and spread evenly, it should be
thoroughly compacted to the recommended minimum relative Compaction.
The fill should be compacted by sheepsfoot rollers, multiple-wheel
pheumatic-tired rollers, or other types of compacting rollers that
content. Each layer should be rolled continuously over its entire
are capable of compacting the fill at the recommended moisture
area until the recornended minimum relative compaction is achieved
throughout the fill.
The fill operation should be continued in layers, as specified above,
until the fill has been brought to the finished slopes and grades
shown on the approved plans.
Fill slopes should be compacted by sheepsfoot rollers, by track-
walking with a dozer, or by other suitable equipment. , Conpaction
operations should continue until the slopes are properly compacted
least 90 percent at a horizontal distance of 2 feet from the slope
(that is, in-place density tests indicate a relative compaction of at
face).
Observation of Grading Operations
The Soil Engineer should make field observations and perform field
and laboratory tests during the filling and compaction operations, so
that he can express his opinion whether or not the grading has been
performed in substantial compliance with project recommendations.
The Soil Engineer should perform in-place density tests in accordance
with accepted ASTH test methods; such density tests should be made in
the Compacted materials below the disturbed surface. When results of’
that recommended, that layer or portion thereof should be reworked
tests taken within any layer indicate a relative compaction below
until the recommended relative compaction is obtained.
-j .? 6.
6.1
6.2
6.3
6.4
7.
7.1
7.2
Oversize Rock Placenent 'v
"Oversize" rock is defined as material that is greater than 6 inches
maximum dimension shou1d:not be used in fills; such material should
and less than 4 feet in maximum dimension. Material over 4 feet in
be exported from the site, broken into acceptably sized pieces, used
for landscaping purposes, or placed in areas designated by the Soil
Engineer andfor approved by appropriate governing agencies.
The Soil Engineer should continuously observe the placement of over-
size rock.
Oversize rock should be placed in lifts not exceeding the maximum
dimension of the rock, and should be placed in a manner that will not
resulc in "nesting" of the rocks. Voids between rocks should be
completely filled with properly compacted (minimum relative com-
paction of 90 percent), fine granular material.
Oversize rock should not be placed within 5 feet of finish pad grade,
within 10 feet of street subgrade, or within 2 feet of the bottom of
the proposed utility lines, whichever is deeper.
Protection of Work
During construction, the contractor should grade the site to provide
positive drainage away from structures and to prevent water from
age adjacent properties or finished work on the site. Positive
ponding adjacent to structures. Water should not be allowed to dam-
drainage should be maintained by the contractor until permanent
with project plans.
drainage and erosion control facilities are installed in accordance
No additional grading shall be done, except under the observation of
the Soil Engineer.
I'