HomeMy WebLinkAboutm91789 (2).pdf.pdfENVIRONMENTAL
GEOTECHNOLOGY
i •ir,+, prM LABORATORY, INC.
2000 April 12, 2000
S & W Development
20547 Walnut Drive, Suite D
Walnut, California 91789
Attention: Mr. Simon Shum
Subject: Response to the City Review Letter dated March 21, 2000, to
Report of Geotechnical Engineering and Geological Investigation
2501 Crowfoot Lane, City of Diamond Bar, California
EGL Project No.: 99-181-006EG
References: 1. Reports of Geotechnical Engineering and Geological Investigation for the
subject site by EGL, Project No.: 99-181-006EG dated August 30, 1999
2. "Final As -Graded Geologic Report, Rough Grading Completed, Tract 30577,
Diamond Bar, California", by Robert Stone & Associates, Job No.: 1-68-303-44
dated September 24, 1971
3. "Redesign of Proposed Buttress Grading, Crowfoot Lane, Lot 61 and 62, Tract
30577, Diamond Bar, County of Los Angeles", by Robert Stone & Associates, Inc.,
Job No.: 1-68-303-33, dated June 11, 1970
Dear Mr. Shum:
This addendum provides EGL's response to the City of Diamond Bar Soil/Geology Review letter,
dated March 21, 2000, for the subject site. For your reference, the review letter is attached and
the responses to each item are presented below.
Item 1
A deep boring, B-1, was drilled, and its location is shown on the attached Site (Geology) Plan.
The boring was drilled to 60 feet below ground surface, and the drilled log is attached. The boring
encountered approximately 9 feet of slopewash overlying the sandstone and siltstone of Puente
Formation. The slopewash is consisted of silty sand, yellowish brown to orange brown, medium
dense with rock fragment. The Puente Formation is consisted of interlayers of sandstone and
siltstone, yellowish brown to orange brown, moderate hard to hard until the depth explored. The
measured bedding attitudes undulate at depths shallower than approximately 33 feet below
ground surface. Below 33 feet deep, the measured bedding attitudes are generally North 60 to 75
degrees West dipping North 15 to 16 degrees. The deep boring information is generally
consistent with the information presented in the Reference #1 report (EGL, 1999).
Item 2
The revised Site (Geology) Plan and cross section are attached in this addendum report.
11823 Slauson Avenue, Unit 18, Santa Fe Springs, GA 90670; Phone: 562-945-0689; Fax: 562-945-0364
E-MAIL: EGL88@AOL.COM
S & W Development
EGL Project Number: 99-181-006EGR
Page 2
April 12, 2000
Item 3
EGL has reviewed the previous reports by Robert Stone & Associates (1970 & 1971). Based on
the referenced reports, it is understood that buttress fills had been placed along Crowfoot Lane
during 1970. The approximate location of these fills was presented in the attached Site (Geology)
Plan. The buttress fill would provide necessary stabilization of the existing site slope.
Item 4
Slope stability analyses have been performed for the subject ]slope. The shear strength of the on -
site materials was determined based on the referenced reports. The following table presents the
selected shear strength parameters:
Materials Unit Weight (pcf) Friction Angle
Static/Seismic
Cohesion (psf)
Static/Seismic
Bedrock (Along Bedding) 120 20/20 150/150
Bedrock (Cross Bedding) 120 30/30 500/500
Based on our stability analysis, it is our opinion that the subject slope slopes are considered
satisfactory and should possess adequate factors of safety against instabilities provided they are
properly maintained. It is also recommended that drainage system be provided behind the shear
keys to prevent the build-up of any hydrostatic pressure.
Item 5
Adequate drainage system should be provided behind the walls to prevent the build-up of any
hydrostatic pressure. Typical retaining wall drainage is presented in the attached figure.
Item 6
Comply.
Item 7
Typical onsite near surface soils were collected and laboratory Expansion Index and Atterberg
Limits were also performed. The following presents the test results:
Soil Type El Liquid Limit (%) Plastic Limit {%)
Siopewash (CL) 35 28 17
Items 8 and 9
Comply.
This opportunity to be of service is sincerely appreciated, and if you have any questions or need
any clarifications pertaining to this report, please call the undersigned.
1G fV ERIn,GRespectfullysubmitted, o H. L c
Q.
Environmental Geotechnology Laboratory Inc. (EGL)
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ECHN" P Hank H. Jong, Ph.D., CEG 1646
Principal OFti Principal
11823 Slauson Avenue, Unit 18, Santa Fe Springs, California 90670; Phone: (562) 945-0689; Fax: (562) 945-0364
E-MAIL EGL88@AOL.COM
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COMPACTED
IMPERVIOUS SOIL
18-INCH MINIMUM
APPROVED FILTER MATERIAL
16-INCH MINIMUM(SEE NOTE)
PERFORATED PIPE(PERFO€iATIONS DOWN)
RAVITY DRAINED OR TO A SUMP PUMP
4-INCH DIAMETER, SCHEDULE 40 OR SDR
35 PVC PIPE(MINIMUM , WITH 2-INCHES
MINIMUM BELOW PIP
SOIL BACKFILL
NOT TO SCALE
NOTES: 1) Approved filter material shall be free -draining materials (SE of 30 or greater) or
Caltrans Class 11 permeable material. As an alternative, 3/4-inch crushed rock may
be substituted for the approved filter material if an approved, nonwoven geotextile
filter fabric is used to encapsulate the 3/4-inch crushed rock (such as MIRAFI 140N or
SUPAC 4NP).
2) Pipe perforations should not exceed a slot width of 116-inch for slotted pipe and
1/4-inch diameter for drilled pipe to avoid migration of fines into the drain pipe.
GEOTECHNICAL REVIEW SHEET
LEIGGHTON AND ASSOCIATES, INC.
FOR
CITY OF DIAMOND BAR
DEPARTMENT OF ENGINEERING
Tract(s) Lot 61, Tract 23483 Date March 21. 2000
Parent Tract
Site Address 2501 Crow Foot Lane
Location/Owner
Geologist Environmental Geotechnical Laboratory Developer
Soils Engineer Environmental Geotechnical Laboratory Engineer/Arch.
REVIEW OF:
Grading P.C. No.
Geologist Report(s) Dated
Soils Report(s) Dated
X Geology and Soils Report(s) Dated August 30. 1999
X Other Grading and Drainage Plan dated Febru .16, 2000
Previous Submittals Dated
ACTION:
Plan/Report is geotechnically approved
Plan/Report is geotechnicaliy approved
subject to conditions below.
REVIEW COMMENTS:
2910164-134
X Plan/Report not approved for reasons below
X Submit Plan/Re ort for recheck. Include a
copy of this review.
Shallow test pits (3 to 4 feet in depth exposing a maximum depth of 2 feet of bedrock) are insufficient to
evaluate the bedrock conditions underlying the site. Deeper geologic data must be obtained to evaluate the
geologic and slope stability conditions_
2. The geologic cross-section must be shown on the Site Geology Plan_ The geologic cross-section must be
appropriately labeled and include the subsurface data and the proposed structures. The section must be
extended beyond the property line, to include slopes above or below the property limits.
2910164-134
3_ The geotechnical consultant should review unpublished and published geotechnical maps and reports from
appropriate sources to further evaluate the site conditions. In addition, aerial photographs of the site should
be reviewed to evaluate site geologic conditions. Reference all material reviewed.
4. The geologic map and cross-section indicate that adversely oriented bedding planes may be present beneath
the slopes onsite. Stability analysis of these slopes must be provided. The consultant must review the need
for subdrainage behind slope stability fills.
5_ Provide specific recommendations for the construction of the recommended retaining wall subdrain system.
6. The geotechnical consultants must review foundation and retaining wall plans and provide appropriate
recommendations.
7. Provide Expansion Index test results for the site. Foundations in expansive soils must be designed in
accordance with Section 1815 or 1816 of the current UBC.
8_ All remedial measures (keys, estimated removal depths, etc_) must be shown on the grading plan. The
grading plan trust include a cut/fill line_ The notes on the grading plan must be updated to current standards
Note 18, Section I I I Statement).
9. Both the Soils Engineer and the Engineering Geologist must sign the grading, plan indicating they have
reviewed the plans from a geotechnical viewpoint_
Reviewed by C Date March 21, 2000
David C. Smith
7 7
Reviewed by Date March 2I. 2000
Philip A. Buchiarelli
u.: 5151L -502-- A4-.S-as&4
APPENDIX
SLOPE STABILITY ANALYSES
Slope stability analyses have been performed for the subject slopes. Selection of coulomb
strength parameters used for the analyses were based on the laboratory test data from the
referenced report and evaluated in light of past experience. A summary of these strength
parameters are presented in the following table:
Unit Weight. Friction Angle Cohesion
Material pcf) Static/Seismic Static/Seismic
Degree) psf)
Along Bedding 120 20120 150/150
Cross Bedding 120 30130 500/500
A summary of the stability analyses and corresponding preliminary geotechnical
recommendations are summarized in the following table, and sections and calculations are
presented on the following plates.
Calculated Conditions
Factor of Safety
Static/seismic)
Conclusions and Preliminary
geotechnical Recommendation
Gross Slope Stability 4.52/2.62 Stable as planned
Slope Stability along Bedding Plane 6.7713.05 Stable as planned
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Slope Stability Analysis --
Simplified Janbu, Simplified Bishop
or Spencer's Method of Slices
Run Date: 04-19-00
Time of Run: 11:08am
Run By: JCL
Input Data Filename: C:99181006.2
Output Filename: C:99181006.OUT
Plotted Output Filename: C:99181006.PLT
PROBLEM DESCRIPTION GROSS STABILITY CONDITION
BOUNDARY COORDINATES
5 Top Boundaries
5 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. ft) ft) ft) ft) Below Bnd
1, 0.00 30.00 53.00 30.00 1
2- 53.00 30.00 172.00 60.00 1
3 172.00 60.00 267.O0 62.00 1
4 267.00 62.00 268.00 62.00 1
5 268.00 62.00 300.00 62.00 1
ISOTROPIC SOIL PARAMETERS
1 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) pcf) psf) deg) Param. psf) No.
1 120.0 120.0 500.0 30.0 0.00 0.0 1
A Critical Failure Surface Searching Method, Using A Random
Technique For Generating Circular Surfaces, Has Been Specified.
10 Trial Surfaces Have Been Generated.
5 Surfaces Initiate From Each Of 2 Points Equally Spaced
Along The Ground Surface Between X = 20.00 ft. and X = 53.00 ft.
Each Surface Terminates Between X = 172.00 ft and X = 250.00 ft.
Unless Further Limitations Were Imposed, The Minimum Elevation
At Which A Surface Extends Is Y = 0.00 ft.
8.00 ft. Line Segments Define Each Trial Failure Surface.
Following Are Displayed The Ten Most Critical Of The Trial
Failure Surfaces Examined. They Are Ordered - Most Critical First.
Safety Factors Are Calculated By The Modified Bishop Method
Failure Surface Specified By 18 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 53.00 30.00
2 60.95 29.09
3 68.93 28.53
4 76.93 28.32
5 84.92 28.47
6 92.91 28.98
7 100.86 29.84
8 108.77 31.05
9 116.62 32.60
10 124.39 34.51
11 132.07 36.75
12 139.64 39.34
13 147.09 42.26
14 154.40 45.50
15 161.56 49.07
16 168.56 52.95
17 175.37 57.13
18 179.85 60.17
Circle Center At X = 77.5 ; Y
4.524
Failure Surface Specified By 25
Point X-Surf Y-Surf
No. ft) ft)
1 20.00 30.00
2 25.86 24.56
3 32.15 19.61
4 38.83 15.21
5 45.85 11.37
6 53.16 8.12
7 60.72 5.49
8 68.46 3.50
9 16.35 2.15
10 84.32 1.45
11 92.32 1.42
12 100.29 2.05
13 108.19 3.34
14 115.95 5.27
15 123.53 7,84
16 130.87 11.02
17 137.92 14.80
18 144.63 19.15
19 150.96 24.04
20 156.87 29.44
21 162.31 35.31
22 167.25 41.60
23 171.64 48.28
24 175.48 55.31
25 177.61 60.12
Circle Center At X = 88.7 ; Y
4.856
Failure Surface Specified By 21
Point X-Surf Y-Surf
No. ft) ft)
1 53.00 30.00
2 58.69 24.38
3 64.97 19.41
4 71.74 15.16
5 78.94 11.67
6 B6.48 8.99
7 94.26 7.14
8 102.20 6.15
9 110.20 6.02
10 118.16 6.78
208.8 and Radius, 180.5
Coordinate Points
98.1 and Radius, 96.7
Coordinate Points
11 126.00 8.39
12 133.61 10.85
13 140.91 14.12
14 147.81 18.17
15 154.23 22.94
16 160.09 28.39
17 165.33 34.44
18 169.87 41.02
19 173.67 48.06
20 176.68 55.47
21 178.00 60.13
Circle Center At X = 107.3 ; Y 79.3 and Radius, 73.4
4.916
Failure Surface Specified By 32 Coordinate Points
Point X-Surf Y-Surf
No. ft) ft)
1 20.00 30.00
2 26.98 26.09
3 34.13 22.50
4 41.43 19.22
5 48.86 16.28
6 56.42 13.66
7 64.09 11.38
8• 71.85 9.44
9 79.69 7.85
10 87.60 6.60
11 95.55 5.71
12 103.53 5.17
13 111.53 4.98
14 119.52 5.14
15 127.51 5.66
16 135.46 6.53
17 143.37 7.75
18 151.21 9.32
19 158.98 11.24
20 166.65 13.50
21 174.22 16.09
22 181.67 19.02
23 188.97 22.27
24 196.13 25.85
25 203.12 29.73
26 209.94 33.92
27 216.56 38.41
28 222.98 43.19
29 229.18 48.25
30 235.15 53.57
31 240.87 59.16
32 243.07 61.50
Circle Center At X = 111.8 ; Y 185.8 and Radius, 180.9
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Slope Stability Analysis --
Simplified Janbu, Simplified Bishop
or Spencer's Method of Slices
Run Date: 04-19-00
Time of Run: 11:09am
Run By: JCL
Input Data Filename: C:99181006.2
Output Filename: C:99181006.OUT
Plotted Output Filename: C:99181006.PLT
PROBLEM DESCRIPTION GROSS STABILITY CONDITION Seismic a=0.15
BOUNDARY COORDINATES
5 Top Boundaries
5 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. ft) ft) ft) ft) Below Bnd
1 0.00 30.00 53.00 30.00 1
2- 53.00 30.00 172.00 60.00 1
3 172.00 60.00 267.00 62.00 1
4 267.00 62.00 268.00 62.00 1
5 268.00 62.00 300.00 62.00 1
ISOTROPIC SOIL PARAMETERS
1 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) pcf) psf) deg) Param. psf) No.
1 120.0 120.0 500.0 30.0 0.00 0.0 1
A Horizontal Earthquake Loading Coefficient Of0.150 Has Been Assigned
A Vertical Earthquake Loading Coefficient Of0.000 Has Been Assigned
Cavitation Pressure = 0.0 psf
A Critical Failure Surface Searching Method, Using A Random
Technique For Generating Circular Surfaces, Has Been Specified.
10 Trial Surfaces Have Been Generated.
5 Surfaces Initiate From Each Of 2 Points Equally Spaced
Along The Ground Surface Between X = 20.00 ft. and X = 53.00 ft.
Each Surface Terminates Between X = 172.00 ft. and X = 250.00 ft.
Unless Further Limitations Were Imposed, The Minimum Elevation
At Which A Surface Extends Is Y = 0.00 ft.
8.00 ft. Line Segments Define Each Trial Failure Surface.
Following Are Displayed The Ten Most Critical Of The Trial
Failure Surfaces Examined. They Are Ordered - Most Critical First-
Safety Factors Are Calculated By The Modified Bishop Method
Failure Surface Specified By 32 Coordinate Points
Point X-Surf Y-Surf
No. (ft) (ft)
1 20.00 30.00
2 27.51 27.23
3 35.10 24.71
4 42.77 22.45
5 50.52 20.45
6 58.33 18.71
7 66.19 17.23
8 74.10 16.01
9 82.04 15.06
10 90.01 14.37
11 98.00 13.95
12 106.00 13.80
13 114.00 13.92
14 121.99 14.30
15 129.96 14.95
16 137.91 15.87
17 145.82 17.05
18 153.69 18.50
19 161.50 20.21
20 169.26 22.18
21 176.94 24.41
22 184.54 26.89
23 192.06 29.63
24 199.48 32.62
25: 206.80 35.85
26 214.01 39.33
27 221.09 43.04
28 228.05 46.99
29 234.87 51.18
30 241.54 55.58
31 248.07 60.21
32 249.95 61.64
Circle Center At X = 106.5 ; Y =
2.617
Failure Surface Specified By 32
Point X-Surf Y-Surf
No. ft) ft)
1 20.00 30.00
2 26.98 26.09
3 34.13 22.50
4 41.43 19.22
5 48.86 16.28
6 56.42 13.66
7 64.09 11.38
8 71.85 9.44
9 79.69 7.85
10 87.60 6.60
11 95.55 5.71
12 103.53 5.17
13 111.53 4.98
14 119.52 5.14
15 127.51 5.66
16 135.46 6.53
17 143.37 7.75
18 151.21 9.32
19 158.98 11.24
20 166.65 13.50
252.9 and Radius, 239.1
Coordinate Points
21 174.22 16.09
22 181.67 19.02
23 188.97 22.27
24 196.13 25.85
25 203.12 29.73
26 209.94 33.92
27 216.56 38.41
28 222.98 43.19
29 229.18 48.25
30 235.15 53.57
31 240.87 59.16
32 243.07 61.50
Circle Center At X = 111.8 ; Y =
2.646
185.8 and Radius, 180.9
Failure Surface Specified By 18 Coordinate Points
Point X-Surf Y-Surf
No. ft) ft)
1 53.00 30.00
2 60.95 29.09
3 68.93 28.53
4 76.93 28.32
5 84.92 28.47
6 92.91 28.98
7 100.86 29.84
8 108.77 31.05
9 116.62 32.60
10 124.39 34.51
11 132.07 36.75
12 139.64 39.34
13 147.09 42.26
14 154.40 45.50
15 161.56 49.07
16 168.56 52.95
17 175.37 57.13
18 179.85 60.17
Circle Center At X = 77.5 ; Y = 208.8 and Radius, 180.5
2.769
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Slope Stability Analysis --
Simplified Janbu, Simplified Bishop
or Spencers Method of Slices
Run Date: 04-19-00
Time of Run: 11:04am
Run By: JCL
Input Data Filename: C:99181006.1
Output Filename: C:99181006.OUT
Plotted Output Filename: C:99181006.PLT
PROBLEM DESCRIPTION BEDDING 13 DEGREE PROPOSED CONDITION
BOUNDARY COORDINATES
6 Top Boundaries
12 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. ft) ft) ft) ft) Below Bnd
1 0.00 30.00 53.00 30.00 1
2 53.00 30.00 53.50 30.00 2
3 53.50 30.00 172.00 60.00 1
4 172.00 60.00 267.00 62.00 1
5 267.00 62.00 268.00 62.00 2
6 268.00 62.00 300.00 62.00 1
7 53.50 30.00 150.00 25.00 2
8 150.00 25.00 266.00 50.00 2
9 266.00 50.00 267.00 62.00 2
10 53.00 30.00 150.00 24.00 1
11 150.00 24.00 267.50 49.00 1
12 267.50 49.00 268.00 62.00 1
ISOTROPIC SOIL PARAMETERS
2 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) pcf) psf) deg) Param. psf) No.
1 120.0 120.0 500.0 30.0 0.00 0.0 1
2 120.0 120.0 150.0 20.0 0.00 0.0 1
Trial Failure Surface Specified By
Point X-Surf Y-Surf
No. ft) ft)
1 53.50 30.00
2 150.00 25.00
3 266.00 50.00
4 267.00 62.00
4 Coordinate Points
Factor Of Safety For The Preceding Specified Surface = 6.766
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Purdue University
Slope Stability Analysis --
Simplified Janbu, Simplified Bishop
or Spencers Method of Slices
Run Date: 04-19-00
Time of Run: 11:11am
Run By: JCL
Input Data Filename: C:99181006.1
Output Filename: C:99181006.OUT
Plotted Output Filename: C:99181006.PLT
PROBLEM DESCRIPTION BEDDING 13 DEGREE PROPOSED CONDITION Seismic a=0.15g
BOUNDARY COORDINATES
6 Top Boundaries
12 Total Boundaries
Boundary X-Left Y-Left X-Right Y-Right Soil Type
No. ft) ft) ft) ft) Below Bnd
1 0.00 30.00 53.00 30.00 1
2 53.00 30.00 53.50 30.00 2
3 53.50 30.00 172.00 60.00 1
4 172.00 60.00 267.00 62.00 1
5 267.00 62.00 268.00 62.00 2
6 268.00 62.00 300.00 62.00 1
7 53.50 30.00 150.00 25.00 2
8 150.00 25.00 266.00 50.00 2
9 266.00 50.00 267.00 62.00 2
10 53.00 30.00 150.00 24.00 1
11 150.00 24.00 267.50 49.00 1
12 267.50 49.00 268.00 62.00 1
ISOTROPIC SOIL PARAMETERS
2 Type(s) of Soil
Soil Total Saturated Cohesion Friction Pore Pressure Piez.
Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface
No. (pcf) pcf) psf) deg) Param. psf) No.
1 120.0 120.0 500.0 30.0 0.00 0.0 1
2 120.0 120.0 150.0 20.0 0.00 0.0 1
A Horizontal Earthquake Loading Coefficient Of0.150 Has Been Assigned
A Vertical Earthquake Loading Coefficient Of0.000 Has Been Assigned
Cavitation Pressure = 0.0 psf
Trial Failure Surface Specified By
Point X-Surf Y-Surf
No. ft) ft)
1 53.50 30.00
2 150.00 25.00
3 266.00 50.00
4 267.00 62.00
4 Coordinate Points
Factor Of Safety For The Preceding Specified Surface = 3.052
Approximate Location -,! ;$ 1° L_.
of Recommended Key 31 $ac
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LEGEND:
Existing contour
New contour
and dip of
25'
Strike
25° bedding
Approximate boring
location
B-1
testzApproximatepitlocation
T-1
A A'
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Cross Section A -A'
Scale: 1 "=40'
Site Address:
Environmental 2501 Crowfoot Lane
Geotechnology Diamond Bar, California
Laboratory
SITE (Geology) PLAN
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EGL BORING LOG B-1
PROJECT LOCATION: 2501 Crowfoot Lane, Diamond Bar, California DATE DRILLIED: 2129I00
PROJECT NO: 99-181-006 SAMPLE METHOD: NIA
ELEVATION: NIA
LOGGED BY: JL
Sample
0
S: Standard Penetration Test
U) R: Ring Sample
o- Description of Materialomin
Slopewash, silty sand, yellowish brown to orange brown,
slightly moist to moist, medium dense, trace rock fragments
5 up to 2 inches
10
Sandstone (Puente Formation), fine to medium grained,
yellowish brown to orange brown, moderate hard,
1 generally massive, interlayers of siltstone
Siltstone interlayers up to 6 inches thick, gray to brown,
moderate hard, occasionally appearwavy
occasional diatomaceous clay layers up to 112 inches thick
N74° E, N20°@ 23'
Sandstone grades to fine grained
N850 W, S120 @ 26'
I — — -4 — — I— — — — — — — — — — — — — — — — — — — — — —
35
EGL BORING LOG B-1
PROJECT LOCATION: 2501 Crowfoot Lane, Diamond Bar, California
PROJECT NO: 99-181-006
DATE DRILLIED: 2/29100
SAMPLE METHOD: NIA
ELEVATION: WA
LVhhtU DT.
Sample
a
E
S: Standard Penetration Test
t
CV
R: Ring Sample
o Description of MaterialocoDinD
Siltstone, gray, moderate hard to hard, slightly moist
35
N75° W, N15-@ 36.5'
40
45
50
55
N60° W, N16- @ 56'
60
Total depth 60 feet
No Groundwater
No Caving
Hale Backfilled
65
GEOTECHNICAL REVIEW SHEET
LEIGHTON AND ASSOCIATES, INC.
FOR
CITY OF DIAMOND BAR
DEPARTMENT OF ENGINEERING
2910164-134
Tract(s) Lot 61. Tract 23483 Date May 19, 2000
Parent Tract
Site Address 2501 Crow Foot Lane
Location/Owner
Geologist Environmental Geotechnical Laboratory Developer
Soils Engineer Environmental Geotechnical Laboratoa Engineer/Arch.
REVIEW OF:
Grading P.C. No.
Geologist Report(s) Dated
Soils Report(s) Dated
X Geology and Soiis Report(s) Dated April 12, 2000
X Other Grading and Drainage Plan dated February 16, 2000
X Previous Submittals Dated August 30. 1999
ACTION:
Plan/Report is geotechnically approved
Plan/Report is geotechnically approved
subject to conditions below.
REVIEW COMMENTS:
X Plan/Report not approved for reasons below
X Submit Plan/Revort for recheck. Include a
copy of this review. ^
1. The boring log and text indicate that slopewash is present to a depth of 9 feet. Bedrock with variable
bedding orientations is reported from 9 to 33 feet. Well bedded bedrock is present below 33 feet. As
described this condition could indicate that a landslide is present to a depth of 33 feet. Slope wash is not
typically present along a ridgeline to a depth of 9 feet. Aerial photographs should be reviewed (as
previously requested) to observe the conditions and the possible presence of existing landslides.
2. A geologic cross-section should be drawn down the 2:1 slope on the east side of the property. It appears
that an out -of -slope bedding condition may exist on this slope. Provide appropriate slope stability
analysis.
3. d during previous site grading is unclear. Why was theThediscussionregardingtheshearkeyconstructe
key constructed? Show the limits of the key.
1' N
2910164-134
4. The slope stability analysis is unclear. Which slope is being analyzed? Show the failure surface being
analyzed on the geotechnical cross -sections.
5. The along -bedding strength parameters used in the analysis are higher than typical for clay layers in the
Puente Formation. Provide justification for the use of these strength parameters or revise_
6. Provide recommendations for the design of foundations in accordance with Section 1815 of the current
Uniform Building Code.
7. All remedial measures (keys, estimated removal depths, etc.) must be shown on the grading plan. The
grading plan must include a cut/fill line. The notes on the grading plan must be updated to current
standards (Note 18, Section 111 Statement).
8. Both the Soils Engineer and the Engineering Geologist must sign the grading plan indicating they have
reviewed the plans from a geotechnical viewpoint.
Reviewed by Date _ Mav 19, 2000
David C. Smith
Reviewed by Date . Mav 19. 2000
Philip A. Buchiareili
N2- _` MEMO
GEOTECHNICAL REVIEW SHEET
LEIGHTON AND ASSOCIATES, INC.
FOR + S
CITY OF DIAMOND BAR
DEPARTMENT OF ENGINEERING
Tract(s) Lot 61. Tract 23483 Date May 19, 2000
Parent Tract Location/Owner
Site Address 2501 Crow Foot Lane
Geologist Environmental Geotechnical Laboratory Developer
Soils Engineer Environmental Geotechnical Laboratory Engineer/Arch.
REVIEW OF:
Grading P.C. No.
Geologist Report(s) Dated
Soils Report(s) Dated
X Geology and Soils Report(s) Dated April 12, 2000
X Other - Grading and Drainage Plan dated February 16. 2000
X Previous Submittals Dated August 30, 1999 _
ACTION:
Plan/Report is geotechnically approved
Plan/Report is geotechnically approved
subject to conditions below.
REVIEW COMMENTS:
2910164-134
X Plan/Report not approved for reasons below
X Submit Plan/Re ort for recheck. Include a
copy of this review.
1. The boring log and text indicate that slopewash is present to a depth of 9 feet. Bedrock with variable
bedding orientations is reported from 9 to 33 feet. Well bedded bedrock is present below 33 feet. As
described this condition could indicate that a landslide is present to a depth of 33 feet. Slope wash is not
typically present along a ridgeline to a depth of 9 feet. Aerial photographs should be reviewed (as
previously requested) to observe the conditions and the possible presence of existing landslides.
2
3.
A geologic cross-section should be drawn down the 2:1 slope on the east side of the property. It appears
that an out -of -slope bedding condition may exist on this slope. Provide appropriate slope stability
analysis.
The discussion regarding the shear key constructed during previous site grading is unclear. Why was the
key constructed? Show the limits of the key.
2910164-134
4. The slope stability analysis is unclear. Which slope is being analyzed? Show the failure surface being
analyzed on the geotechnical cross -sections.
5. The along -bedding strength parameters used in the analysis are higher than typical for clay layers in the
Puente Formation. Provide justification for the use of these strength parameters or revise.
6. Provide recommendations for the design of foundations in accordance with Section 1815 of the current
Uniform Building Code.
7. All remedial measures (keys, estimated removal depths, etc.) must be shown on the grading plan. The
grading plan must include a cut/fill line. The notes on the grading plan must be updated to current
standards (Note 18, Section 111 Statement).
8. Both the Soils Engineer and the Engineering Geologist must sign the grading plan indicating they have
reviewed the plans from a geotechnical viewpoint.
Reviewed by _ Date Mav 19.2000
David C_ Smith
Reviewed by Date Mav 19.2000
T,
Philip A. Buchiareili
1
21660 EAST COPLEY DRIVE, SUITE 100
DIAMOND BAR CA 91765-4177
909-860-2489 9 FAX 909-861-3117
5, U-(!:>
COMMUNITY & DEVELOPMENT SERVICES DEPARTMENT
LETTER OF TRANSMITTAL
TO: Leighton & Assoc.
WE ARE SENDING YOU
Shop drawings
Copy of Letter
DATE: 4124/00 JOB NO.: G-00-407
ATTENTION: David Smith
RE: 2501 CROW FOOT LN.
Attached Under separate cover via
Prints X Plans Samples
Change Order X Other Report
the following items.
Specs.
COPIES DATE NO. DESCRIPTION
1 Response to the City Review dated March 21, 2000...
4/12/00 Grading & Drainage Plan
THESE ARE TRANSMITTED as checked below:
For approval
For your use
As requested
X Review/comment
FOR BIDS DUE
Approved as submitted
Approved as noted
Returned for corrections
Other (see remarks)
Resubmit _ copies for approval
Submit _ copies for distribution
Return corrected prints
PRINTS RETURNED AFTER LOAN TO US
REMARKS: 2nd Sub. P.O. #9754. Pleasepick-up @ City ASAP. Thank you.
COPY TO: FILE
John L.1lasin, E.I.
SIGNED: Engineering Te an