HomeMy WebLinkAbout971009-005; Bressi Ranch Lennar Homes Part 2; Mass Grading Bressi Ranch Part 2; 2001-03-14971009-005
APPENDIX C
Laboratory Testing Procedures and Test Results
Atterberg Limits: The Atterberg Limits were determined in accordance with ASTM Test Method D4318 for
engineeringclassificationof the fine-grained materials and presented in the table below:
Sample Location
B-2#7@40'
B-3 #7 @30'
B-5#6@20'
B-6#4@15'
Liquid
Limit (%)
35
39
42
42
Plastic
Limit (%)
16
16
20
17
Plastic
Index (%)
19
22
22
25
USCS Soil
Classification
CL
CL
CL
CL
Direct Shear Tests: Direct shear tests were performed on selected remolded and/or undisturbed samples,
which were soaked for a minimum of 24 hours under a surcharge equal to the applied normal force during
testing. After transfer of the sample to the shear box and reloading of the sample, the pore pressures set up
in the sample (due to the transfer) were allowed to dissipate for a period of approximately 1 hour prior to
application of shearing force. The samples were tested under various normal loads utilizing a motor-driven,
strain-controlled, direct-shear testing apparatus at a strain rate of less than 0.001 to 0.5 inches per minute
(depending upon the soil type). The test results are presented in the test data.
Sample Location
LB-25#3@11-
14'
LB-25#8@53'
LB-26#4@20'
LB-28#1@10'
Sample Description
Pale brown silty SAND
Green gray CLAY
Pale green sandy CLAY
Pale yellow silty SAND
Test Type
Remolded to
90%
Remolded to
90%
Undisturbed
Undisturbed
Friction Angle
(degrees)
30
26
25
25
Apparent
Cohesion (psf)
460
180
750
100
Moisture and Density Determination Tests: Moisture content and dry density determinations were
performed on relatively undisturbed samples obtained from the test borings and/or trenches. The results of
these tests are presented in the boring and/or trench logs. Where applicable, only moisture content was
determined from "undisturbed" or disturbed samples.
C-l
971009-005
APPENDIX C (Continued)
Expansion Index Tests: The expansion potential of selected materials was evaluated by the Expansion Index
Test, U.B.C. Standard No. 18-2 and/or ASTM Test Method 4829. Specimens are molded under a given
compactive energy to approximately the optimum moisture content and approximately 50 percent saturation
or approximately 90 percent relative compaction. The prepared 1-inch thick by 4-inch diameter specimens
are loaded to an equivalent 144 psf surcharge and are inundated with tap water until volumetric equilibrium
is reached. The results of these tests are presented in the table below:
Sample Location Sample Description
Light brown clayey silty sand to
sandy clay
Compacted Dry
Density (per)
101.5
Expansion
Index
28
Expansion
Potential
Low
Maximum Dry Density Tests: The maximum dry density and optimum moisture content of typical materials
were determined in accordance with ASTM Test Method Dl 557. The results of these tests are presented in
the table below:
Sample Location
LB-25#3@11-14'
LB-25#8@53'
Sample Description
Pale brown silty SAND
Green gray CLAY
Maximum Dry
Density (pcf)
117.5
111.0
Optimum Moisture
Content (%)
13.5
17.5
Consolidation Tests: Consolidation tests were performed on selected, relatively undisturbed ring samples in
accordance with Modified ASTM Test Method D2435. Samples were placed in a consolidometerand loads
were applied in geometric progression. The percent consolidation for each load cycle was recorded as the
ratio of the amount of vertical compression to the original 1-inch height. The consolidation pressure curves
are presented on the attached figures. Where applicable, time-rates of consolidation were recorded and
presented below:
Sample Location
B-2@20'
B-3 @20'
B-5@15'
Coefficient of Consolidation Cv
(cmVsec)
2.2 xlO'3
2.3 x W4
2.9 xlO"4
C-2
TERATEST LABS,
DIRECT SHEAR TEST RESULT
ASTM D 3080
Project Name:
Project Number:
Boring Number:
Sample Number:
Soil Description:
BRESSI RANCH
971009-005
LB-25
3
PALE BROWN SILTY SAND (SM)
Date: 10/31/00
Tested By: BCC
Checked By: ffl*-^
Depth (ft.): 11.0-14.0
VERTICAL STRESS
(psf)
554
1108
2216
PROVING RING
DIAL READING
PEAK
51
101
127
RELAXED
44
83
104
CONVERSI
ON
FACTOR
15
15
15
SHEAR
STRESS
(psf)
765
1515
1905
RELAXED
STRESS
(psf)
660
1245
1560
PEAK
COHESION (psf)
FRICTION (dag.)
550
35
RELAXED
COHESION (psf)
FRICTION (deg.)
460
30
z
%
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,
*
30
f
*
0
{
s '
**
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'
t
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S
2
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^
500
TERATEST LABS, INC.
DIRECT SHEAR TEST RESULT
ASTM D 3080
Project Name:
Project Number:
Boring Number:
Sample Number:
Soil Description:
BRESSI RANCH
971009-005
LB-25
8
GREENISH GRAY LEAN CLAY (CL)
Date: 10/31/00
Tested By: BCC
Checked By: jft£/
Depth (ft.): 53.0
VERTICAL STRESS
(psf)
554
1108
2216
PROVING RING
DIAL READING
PEAK
35
54
99
RELAXED
31
45
86
CONVERSI
ON
FACTOR
15
15
15
SHEAR
STRESS
(psf)
525
810
1485
RELAXED
STRESS
(psf)
465
675
1290
PEAK
COHESION (psf)
FRICTION (deg.)
200
30
RELAXED
COHESION (psf)
FRICTION (deg.)
180
26
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a.
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mnn .
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>^'•*'*•
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500
TERATEST LABS, IN c.
DIRECT SHEAR TEST RESULT
ASTM D 3080
Project Name:
Project Number:
Boring Number:
Sample Number:
Soil Description:
BRESSI RANCH
971009-005
LB-26
4
PALE GREEN SANDY LEAN CLAY s(CL)
Date: 10/30/00
Tested By: BCC
Checked By: SfU^
Depth (ft.): 20.0
VERTICAL STRESS
(psf)
554
1108
2216
PROVING RING
DIAL READING
PEAK
77
84
138
RELAXED
74
78
127
CONVERSI
ON
FACTOR
15
15
15
SHEAR
STRESS
(psf)
1155
1260
2070
RELAXED
STRESS
(psf)
1110
1170
1905
PEAK
COHESION (psf)
FRICTION (deg.)
750
29
RELAXED
COHESION (psf)
FRICTION (deg.)
750
25
•(Knn ,STRAIN (psf)3 ID CD C*ion .
*
-
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_
^*
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ii
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0 500 1000 1500 2000 2500
STRESS (psf)
TERATEST LABS, INC.
DIRECT SHEAR TEST RESULT
ASTM D 3080
Project Name:
Project Number:
Boring Number:
Sample Number:
Soil Description:
BRESS1 RANCH
971009-005
LB-28
1
Date: 10/30/00
Tested By: BCC
Checked By:
Depth (ft.):10.0
PALE YELLOW POORLY-GRADED SAND WITH SILT (SP-SM)
VERTICAL STRESS
(psf)
554
1108
2216
PROVING RING
DIAL READING
PEAK
33
103
160
RELAXED
30
98
147
CONVERSI
ON
FACTOR
15
15
15
SHEAR
STRESS
(psf)
495
1545
2400
RELAXED
STRESS
(psf)
450
1470
2205
PEAK
COHESION (psf)
FRICTION (deg.)
100
49
RELAXED
COHESION (psf)
FRICTION (deg.)
100
47
STRAIN (psf)-xD C3 C3 Ci t'
A tr
A~
-
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1¥I
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-
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._,
0 500 1000 1500 2000 2500
STRESS (psf)
Leightonand Associates, Inc.
GENERAL EARTHWORKANDGRADINGSPECIFICATIONS
Page 1 of 6
LEIGHTON AND ASSOCIATES, INC.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS FOR ROUGH GRADING
1.0 General
1.1 Intent: These General Earthwork and Grading Specifications are for the grading and
earthwork shown on the approved grading plan(s) and/or indicated in the geotechnical
report(s). These Specifications are a part of the recommendations contained in the
geotechnical report(s). In case of conflict, the specific recommendations in the
geotechnical report shall supersede these more general Specifications. Observations of the
earthwork by the project Geotechnical Consultant during the course of grading may result
in new or revised recommendations that could supersede these specifications or the
recommendations in the geotechnical report(s).
1.2 The Geotechnical Consultant of Record: Prior to commencement of work, the owner shall
employ the Geotechnical Consultant of Record (Geotechnical Consultant). The
Geotechnical Consultants shall be responsible for reviewing the approved geotechnical
report(s) and accepting the adequacy of the preliminary geotechnical findings, conclusions,
and recommendations prior to the commencement of the grading.
Prior to commencement of grading, the Geotechnical Consultant shall review the "work
plan" prepared by the Earthwork Contractor (Contractor) and schedule sufficient personnel
to perform the appropriate level of observation, mapping, and compaction testing.
During the grading and earthwork operations, the Geotechnical Consultant shall observe,
map, and document the subsurface exposures to verify the geotechnical design
assumptions. If the observed conditions are found to be significantly different than the
interpreted assumptions during the design phase, the Geotechnical Consultant shall inform
the owner, recommend appropriate changes in design to accommodate the observed
conditions, and notify the review agency where required. Subsurface areas to be
geotechnically observed, mapped, elevations recorded, and/or tested include natural ground
after it has been cleared for receiving fill but before fill is placed, bottoms of all "remedial
removal" areas, all key bottoms, and benches made on sloping ground to receive fill.
The Geotechnical Consultant shall observe the moisture-conditioningand processing of the
subgrade and fill materials and perform relative compaction testing of fill to determine the
attained level of compaction. The Geotechnical Consultant shall provide the test results to
the owner and the Contractor on a routine and frequent basis.
3030.1094
Leightonand Associates, Inc.
GENERALEARTHWORKANDGRADINGSPECIFICATIONS
Page 2 of 6
1.3 The Earthwork Contractor: The Earthwork Contractor (Contractor) shall be qualified,
experienced, and knowledgeable in earthwork logistics, preparation and processing of
ground to receive fill, moisture-conditioning and processing of fill, and compacting fill.
The Contractor shall review and accept the plans, geotechnical report(s), and these
Specifications prior to commencement of grading. The Contractor shall be solely
responsible for performing the grading in accordance with the plans and specifications.
The Contractor shall prepare and submit to the owner and the Geotechnical Consultant a
work plan that indicates the sequence of earthwork grading, the number of "spreads" of
work and the estimated quantities of daily earthwork contemplated for the site prior to
commencement of grading. The Contractor shall inform the owner and the Geotechnical
Consultant of changes in work schedules and updates to the work plan at least 24 hours in
advance of such changes so that appropriate observations and tests can be planned and
accomplished. The Contractor shall not assume that the Geotechnical Consultant is aware
of all grading operations.
The Contractor shall have the sole responsibility to provide adequate equipment and
methods to accomplish the earthwork in accordance with the applicable grading codes and
agency ordinances, these Specifications, and the recommendations in the approved
geotechnical report(s) and grading plan(s). If, in the opinion of the Geotechnical
Consultant, unsatisfactory conditions, such as unsuitable soil, improper moisture condition,
inadequate compaction, insufficient buttress key size, adverse weather, etc., are resulting in
a quality of work less than required in these specifications, the Geotechnical Consultant
shall reject the work and may recommend to the owner that construction be stopped until
the conditions are rectified.
2.0 Preparation of Areas to be Filled
2.1 Clearing and Grubbing: Vegetation, such as brush, grass, roots, and other deleterious
material shall be sufficiently removed and properly disposed of in a method acceptable to
the owner, governing agencies, and the Geotechnical Consultant.
The Geotechnical Consultant shall evaluate the extent of these removals depending on
specific site conditions. Earth fill material shall not contain more than 1 percent of organic
materials (by volume). No fill lift shall contain more than 5 percent of organic matter.
Nesting of the organic materials shall not be allowed.
If potentially hazardous materials are encountered, the Contractor shall stop work in the
affected area, and a hazardous material specialist shall be informed immediately for proper
evaluation and handling of these materials prior to continuing to work in that area.
As presently defined by the State of California, most refined petroleum products (gasoline,
diesel fuel, motor oil, grease, coolant, etc.) have chemical constituents that are considered
to be hazardous waste. As such, the indiscriminate dumping or spillage of these fluids
onto the ground may constitute a misdemeanor, punishable by fines and/or imprisonment,
and shall not be allowed.
3030.1094
Leighton and Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 3 of 6
2.2 Processing: Existing ground that has been declared satisfactory for support of fill by the
Geotechnical Consultant shall be scarified to a minimum depth of 6 inches. Existing
ground that is not satisfactory shall be overexcavatedas specified in the following section.
Scarification shall continue until soils are broken down and free of large clay lumps or
clods and the working surface is reasonably uniform, flat, and free of uneven features that
would inhibit uniform compaction.
2.3 Overexcavation: In addition to removals and overexcavations recommended in the
approved geotechnical report(s) and the grading plan, soft, loose, dry, saturated, spongy,
organic-rich, highly fractured or otherwise unsuitable ground shall be overexcavated to
competent ground as evaluated by the Geotechnical Consultant during grading.
2.4 Benching: Where fills are to be placed on ground with slopes steeper than 5:1 (horizontal
to vertical units), the ground shall be stepped or benched. Please see the Standard Details
for a graphic illustration. The lowest bench or key shall be a minimum of 15 feet wide and
at least 2 feet deep, into competent material as evaluated by the Geotechnical Consultant.
Other benches shall be excavated a minimum height of 4 feet into competent material or as
otherwise recommended by the Geotechnical Consultant. Fill placed on ground sloping
flatter than 5:1 shall also be benched or otherwise overexcavated to provide a flat subgrade
for the fill.
2.5 Evaluation/Acceptance of Fill Areas: All areas to receive fill, including removal and
processed areas, key bottoms, and benches, shall be observed, mapped, elevations
recorded, and/or tested prior to being accepted by the Geotechnical Consultant as suitable
to receive fill. The Contractor shall obtain a written acceptance from the Geotechnical
Consultant prior to fill placement. A licensed surveyor shall provide the survey control for
determiningelevations of processed areas, keys, and benches.
3.0 Fill Material
3.1 General: Material to be used as fill shall be essentially free of organic matter and other
deleterious substances evaluated and accepted by the Geotechnical Consultant prior to
placement. Soils of poor quality, such as those with unacceptable gradation, high
expansion potential, or low strength shall be placed in areas acceptable to the Geotechnical
Consultant or mixed with other soils to achieve satisfactory fill material.
3.2 Oversize: Oversize material defined as rock, or other irreducible material with a maximum
dimension greater than 8 inches, shall not be buried or placed in fill unless location,
materials, and placement methods are specifically accepted by the Geotechnical
Consultant. Placement operations shall be such that nesting of oversized material does not
occur and such that oversize material is completely surrounded by compacted or densified
fill. Oversize material shall not be placed within 10 vertical feet of finish grade or within
2 feet of future utilities or underground construction.
3030.1094
Leightonand Associates, Inc.
GENERALEARTHWORKANDGRADINGSPECIFICATIONS
Page 4 of 6
3.3 Import: If importing of fill material is required for grading, proposed import material shall
meet the requirements of Section 3.1. The potential import source shall be given to the
Geotechnical Consultant at least 48 hours (2 working days) before importing begins so that
its suitability can be determined and appropriate tests performed.
4.0 Fili Placementand Compaction
4.1 Fill Layers: Approved fill material shall be placed in areas prepared to receive fill (per
Section 3.0) in near-horizontal layers not exceeding 8 inches in loose thickness. The
Geotechnical Consultant may accept thicker layers if testing indicates the grading
procedures can adequately compact the thicker layers. Each layer shall be spread evenly
and mixed thoroughly to attain relative uniformity of material and moisture throughout.
4.2 Fill Moisture Conditioning: Fill soils shall be watered, dried back, blended, and/or mixed,
as necessary to attain a relatively uniform moisture content at or slightly over optimum.
Maximum density and optimum soil moisture content tests shall be performed in
accordance with the American Society of Testing and Materials (ASTM Test Method
D1557-91).
4.3 Compaction of Fill: After each layer has been moisture-conditioned, mixed, and evenly
spread, it shall be uniformly compacted to not less than 90 percent of maximum dry density
(ASTM Test Method Dl 557-91). Compaction equipment shall be adequately sized and be
either specifically designed for soil compaction or of proven reliability to efficiently
achieve the specified level of compaction with uniformity.
4.4 Compaction of Fill Slopes: In addition to normal compaction procedures specified above,
compaction of slopes shall be accomplished by backrolling of slopes with sheepsfoot
rollers at increments of 3 to 4 feet in fill elevation, or by other methods producing
satisfactory results acceptable to the Geotechnical Consultant. Upon completion of
grading, relative compaction of the fill, out to the slope face, shall be at least 90 percent of
maximum density per ASTM Test Method Dl 557-91.
4.5 Compaction Testing: Field tests for moisture content and relative compaction of the fill
soils shall be performed by the Geotechnical Consultant. Location and frequency of tests
shall be at the Consultant's discretion based on field conditions encountered. Compaction
test locations will not necessarily be selected on a random basis. Test locations shall be
selected to verify adequacy of compaction levels in areas that are judged to be prone to
inadequate compaction (such as close to slope faces and at the fill/bedrock benches).
3030.1094
Leightonand Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 5 of 6
4.6 Frequency of Compaction Testing: Tests shall be taken at intervals not exceeding2 feet in
vertical rise and/or 1,000 cubic yards of compacted fill soils embankment. In addition, as a
guideline, at least one test shall be taken on slope faces for each 5,000 square feet of slope
face and/or each 10 feet of vertical height of slope. The Contractor shall assure that fill
construction is such that the testing schedule can be accomplished by the Geotechnical
Consultant. The Contractor shall stop or slow down the earthwork construction if these
minimum standards are not met.
4.7 Compaction Test Locations: The Geotechnica! Consultant shall document the approximate
elevation and horizontal coordinates of each test location. The Contractor shall coordinate
with the project surveyor to assure that sufficient grade stakes are established so that the
Geotechnical Consultant can determine the test locations with sufficient accuracy. At a
minimum, two grade stakes within a horizontal distance of 100 feet and vertically less than
5 feet apart from potential test locations shall be provided.
5.0 Subdrain Installation
Subdrain systems shall be installed in accordance with the approved geotechnical report(s), the
grading plan, and the Standard Details. The Geotechnical Consultant may recommend additional
subdrains and/or changes in subdrain extent, location, grade, or material depending on conditions
encountered during grading. All subdrains shall be surveyed by a land surveyor/civil engineer for
line and grade after installation and prior to burial. Sufficient time should be allowed by the
Contractor for these surveys.
6.0 Excavation
Excavations, as well as over-excavation for remedial purposes, shall be evaluated by the
Geotechnical Consultant during grading. Remedial removal depths shown on geotechnical plans
are estimates only. The actual extent of removal shall be determined by the Geotechnical
Consultant based on the field evaluation of exposed conditions during grading. Where fill-over-cut
slopes are to be graded, the cut portion of the slope shall be made, evaluated, and accepted by the
Geotechnical Consultant prior to placement of materials for construction of the fill portion of the
slope, unless otherwise recommended by the Geotechnical Consultant.
3030.1094
Leightonand Associates, Inc.
GENERAL EARTHWORK AND GRADING SPECIFICATIONS
Page 6 of 6
7.0 Trench Backfills
7.1 The Contractor shall follow all OHSA and Cal/OSHA requirements for safety of trench
excavations.
7.2 All bedding and backfill of utility trenches shall be done in accordance with the applicable
provisions of Standard Specifications of Public Works Construction. Bedding material
shall have a Sand Equivalent greater than 30 (SE>30). The bedding shall be placed to 1
foot over the top of the conduit and densified by jetting. Backfill shall be placed and
densified to a minimum of 90 percent of maximum from 1 foot above the top of the
conduit to the surface.
7.3 The jetting of the bedding around the conduits shall be observed by the Geotechnical
Consultant.
7.4 The Geotechnical Consultant shall test the trench backfill for relative compaction. At least
one test should be made for every 300 feet of trench and 2 feet of fill.
7.5 Lift thickness of trench backfill shall not exceed those allowed in the Standard
Specifications of Public Works Construction unless the Contractor can demonstrate to the
Geotechnical Consultant that the fill lift can be compacted to the minimum relative
compaction by his alternative equipment and method.
3030.1094
PROJECTED PLANE
1TO1 MAMMUM FROM TOE
OF SLOPE TO APPROVED GROUND
NATURAL
GROUND
FILL SLOPE
REMOVE
UNSUITABLE
MATERIAL
BENCH
HEIGHT
2'MIN.
KEY DEPTH
—15' MIR
LOWEST BENCH
(KEY)
NATURAL
GROUND
t— BENCH
HEIGHT
FILL-OVER-CUT
SLOPE
REMOVE
UNSUITABLE
MATERIAL
I—2'MIN.
KEY DEPTH
OUTFACE
SHALL BE CONSTRUCTED PRIOR
TO RLL PLACEMENT TO ASSURE
ADEQUATE GEOLOGIC CONDTTTONS
CUT FACE
TO BE CONSTRUCTED PRIOR
TO FILL PLACEMENT^
NATURAL
GROUND
OVERBUILT AND
TRIM BACK
PROJECTED PLANE
1TO1 MAXIMUM FROM
TOE OF SLOPE TO
APPROVED GROUND
<s>«r
CUT-OVER-FILL
SLOPE
DESIGN SLOPE REMOVE
NSUITABLE
MATERIAL
For Subdrains See
Standard Detail C
BENCH HEIGHT
2* MIN.-
KEY DEPTH
.15'
LOWEST BENCH
(KEY)
8ENCHNG SHAU BE DONE WHEN SLOPES
ANGLE IS EQUAL TO OR GREATER THAN 5:1
MINMUM BENCH HEIGHT SHALL BE 4 FEET
MINIMUM FILL WIDTH SHALL BE 9 FEET
KEYING AND BENCHING GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS A
ia->
uu
REV. 4/11/96
FINISH GRADE
SLOPE
FACE
---"--——-*?^-—I-I-^^^^-i-i-i-i-2£E^-i-l^--_-_--^^^
.- - _ _ .-_ j-r _^*^^ __ - _
—_———-———-A-\*^if —**———__
JETTED OR FLOODED
GRANULAR MATERIAL
• Oversize rock te larger than 8 Inches
In largest dimension.
• Excavate a trench in the compacted
fill deep enough to bury all the rock.
• Backfill with granular soil jetted or
flooded in place to fid all the voids.
• Do not bury rock within 10 feet of
finish grade.
• Windrow of buried rock shaH be
parallel to the finished slope fid.ELEVATION A-Af
PROFILE ALONG WINDROW
—A—
JETTED OR FLOODED
GRANULAR MATERIAL
OVERSIZE
ROCK DISPOSAL
GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS B
ia-s.
4/95
NATURAL
GROUND
BENCHING REMOVE
UNSUITABLE
MATERIAL
- COMPACTED FILL ^TL—_^nr^rrr-_-
V MIN. OVERLAP FROM THE TOP
HOG RING TIED EVERY 6 FEET
CALTRANS CLASS II
PERMEABLE OR #2 ROCK"
(9FT.VFT.) WRAPPED IN
FILTER FABRIC
FILTER FABRIC
(MIRAF1 140 ORV \ X
\COLLECTOR PIPE SHALL
CANYON SUBDRAIN OUTLET DETAIL
PERFORATED PIPE
MIN.
APPROVEDEQUIVALENT) BE MINIMUM 6- DIAMETERSCHEDULE 40 PVC PERFORATED
PIPE. SEE STANDARD DETAIL D
FOR PIPE SPECIFICATION
DESIGN
RNISHED
GRADE
a o
FILTER FABRIC
(MIRAFI 140 OR
APPROVED
EQUIVALENT)
20* MIN.-
. NON-PERFORATED
6'* MIN.
V,5* MIN.ROCK WRAPPED IN FILTER
FABRIC OR CALTRANS CLASS II
PERMEABLE.
CANYON SUBDRAINS GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS C
<i)-»
LU
4/95
OUTLET PIPES
4'* NON-PERFORATED PIPE,
100' MAX. O.C. HORIZONTALLY,
30' MAX. O.C. VERTICALLY BACKCUT1:1
OR FLATTER
KEY -v
DEPTH J
2' MIN.
POSITIVE SEAL
SHOULD BE
PROVIDED AT
THE JOI
12- MIN. OVERLAP FROM THE TOP
HOG RING TIED EVERY 6 FEET
v:
OUTLET PIPE
(NON-PERFORATED)
CALTRANS CLASS II
PERMEABLE OR *2 ROCK
<3FT.*/FT.) WRAPPED IN
FILTER FABRIC
FILTER FABRIC
(MIRAFM40OR
APPROVED
EQUIVALENT)
T-CONNECT1ON FOR
COLLECTOR PIPE TO
OUTLET PIPE
• SUBDRAIN INSTALLATION - Subdraln collector pipe shall be installed with perforations down or,
unless otherwise designated by the geotechnlcaf consultant Outlet pipes shaft be non-perforated
pipe. The subdrain pipe shad have at toast 8 perforations uniformly spaced per foot. Perforation shaft
be W to W if drilled holes are used. All subdrain pipes shall have a gradient at least 2% towards the
outlet
• SUBDRAIN PIPE - Subdrain pipe shall be ASTM D2751, SDR 23.5 or ASTM D1527, Schedule 40, or
ASTM D3034, SDR 23.5, Schedule 40 Pofyvinyi Chloride Plastic (PVC) pipe.
• All outlet pipe shall be placed in a trench no wider than twice the subdrain pipe. Pipe shall be in soil
of SE>.30 jetted or flooded in place except for the outside 5 feet which shall be native soil backfill.
BUTTRESS OR
REPLACEMENT FILL
SUBDRAINS
GENERAL EARTHWORK AND GRADING
SPECIFICATIONS
STANDARD DETAILS D
ia->
LU
4/95