HomeMy WebLinkAbout30578 (48)lyTRIADFOUNDATIONENG19; ;1 pC
Foundation Engineering Engineering GeologyVFMaterialTesting * Construction Inspection
17231 EAST RAILROAD STREET, SUITE 100, CITY OF INDUSTRY, CA 91748
TELEPHONE (818) 964-2313
FAX (818) 810-0915
Sun -Ray
1724 Leaning Pine
July 3, 1989
Job #88-494
Pftrk
Diamond Bar, CA 91765 'JUL 10 'Y,qg 9
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Subject: Supplemental Geotechnical Data
and Review of Revised Grading Plan L06
Lot 36; Tract 30578 V.
22105 Rim Fire Lane
Diamond Bar, California
References: 1) Preliminary Soils & Geologic Investigation
By Triad Foundation Engineering, Inc.
Dated 9-8-88
2) County Geologic Review Sheet dated 11-21-88
3) Supplemental Geotechnical Data & Review of
Revised Grading Plan
By Triad Foundation Engi-,eering, Inc.
Dated 3-21-89
4) County Geologic Review Sheet dated 5-19-89
5) County Soils Review Sheet dated 5-18-89
Gentlemen:
Additional subsurface exploration was conducted downslope on the
site as requested by the County Geologist (Reference #4). The
location of the three Test PIts (#2, 3 and 4) and the data
obtained are plotted on the attached Geologic Map and Cross
Sections.
1
Additional geologic data downslope shows a slight steepening of
the apparent dip shown on the attached Cross Sections A -A' and B-
B'. Stability calculations contained in our Preliminary Report
on the natural slope indicate it to have an acceptable factor of
safety of 1.5.
The present grading concept is to place a fill to support the
house. As drawn on the plan it appears this fill will slope at
an average angle of 30 degrees and will be supported by a crib
wall as high as 40 feet. As noted on the plan the fill slope
will be at 34 degrees (1.5:1) and will be supported by a 26 foot
high crib wall. We presume the latter is the case.
A portion of this fill will encroach onto the restricted use area
as designated by Robert Stone and Associates in their report of
11-5-70 as an area of slumping and landsliding. Test Pit #4
indicates the rock to be relatively undisturbed. Test Pit #3
indicates the rocks to be moderately weathered and fractured to
about 4.5 feet. Below this point the rock is slightly weathered
and difficult to excavate with little or no fracturing. Based on
this data we have repositioned the edge of the area of slumping
and landsliding towards the east (See attached Geologic Map). It
appears therefore that much of the east edge of the fill will be
outside this affected area.
iq
Sails Engineer's Response
The following comments are in response to the soils review,
reference #5.
Item 1.
With the additional field investigation we are no longer relying
on previous reports and our reports are adequate for analysis of
the site.
Item 2.
By others.
Item 3.
Bedding planes are well,,pu true dip,ap p nppp; ,
how on t e
encloc.9qlq0c Map, and Cross Sections with.''tag 4 i9pal
P,,/xploxAt,4,on,, Additional slope stability calculations with
the good bedrock conditions reported in the enclosed Test PIt
Logs are not required.
Footings encroaching the compacted fill slope should have a
horizontal distance of 7 feet from the bottom side of the footing
to the face of the compacted fill slope as a minimum.
K
The opportunity to be of service to you on this project is
appreciated, and if you have any questions, please call us at
your convenience.
Respectfully submitted,
TRIAD FOUNDATION ENGINEERING, INC.
WGU;FCS/thf
Distribution:
Enclosures:
Addressee (4)
Frank C. Stillman
G.E. 805
L.A. County Review Sheets
Plate A --- Cross Sections
Plates B-2 thru B-4 --- Test Pit Logs
Geologic Map
4
William G. Uhl
C.E.G. 502
WGU;FCS/thf
Distribution:
Enclosures:
Addressee (4)
Frank C. Stillman
G.E. 805
L.A. County Review Sheets
Plate A --- Cross Sections
Plates B-2 thru B-4 --- Test Pit Logs
Geologic Map
4
V rC
GEOLOGIC REVIEW SHEET
Sheet L. A. COUNTY DEPARTMENT OF PUBLIC WORKS
Of
goo SO. FREMONT AVE.. ALHAMBRA, CA 91603
LAND DEVELOPMENT DIVISION
Lot(s)
roc PM
Parent Tract
Location
Site Address
Geologist
Developer
01F
Sails Engineer
Engineer/Arch-
Review Of:
r
Grading P.C. No.
Geologic Report(s) Dat
Soils Report(s) Dated
7 Geology and Soils Repo
Dist. Office
NF
DISTRIBUTION
Dist. Engineer
Geologist —
Soils Engineer
1 Geo. Sect. File
Grading Section
Health Dept.
Engineer
Building P.C. No. For:
Action: Plan is geologically approved. ,"-Plan is not approved for reasons below.
Plan approved geologically subject Submit plans for recheck. Include a copy
of this review and aILletoconditionsbelof2arts.
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Remarks: _4Z _5
1. Site C04d not be located in field. Provide prominent address sign at site. Stake corners of lot wit
highly visible flagging. Provide detailed location map with odometer mileage from road intersections.
2. No apparent geologic hazards, as defined by Los Angeles County, were observed at building site. A geologi.
report should not be required.
Z3. Comply with previous ge&4*V*=fsoJls review sheet(s) dated
41- 3
ew, Lbmit plans and/or reports. 4
4.A Required pJaAs_:5avd/=sMeP&
5. The reference4 report(s) is acknowledge and filed.
7 f - ko ;- 6 "— "
J
0 / et
Resubmit two original copies of al
6. The reportfs)l submji ited were eithl illegible o incomplete, or both.
geotechnical reports for this project, tproduced copies are not acceptable.
7. Report(s) can not be reviewed until the plans have been reviewed and approved by the geotechnica
consultants, by manual, ori final signatures and dates on each sheet of the plan.
B. 8 , uilding Plans can't.be approved until completion of rough grading, and approval by the Geology Section
based on the final Geology and Soils Report (submit at completion of grading). Do not resubmit buildio
pla S
ants: 2, 4 rr r -- -; ?/" "
vim. 4-""
d bReviewed y Date
Prepared by . Rev—
r , 1:GL3 07\ 2.7 C, - 1
e
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GEOLOGIC REVIEW SHEET
Sheet of L. A. COUNTY DEPARTMENT OF PUBLIC WORKS
900 SO. FREMONT AVE,, ALWORA, CA 91803
WD DEVELOPMENT DIVISION
ract/PM
Parent Tract
ate Address P,
Geologist
Soils Engineer vg A
Lot(s)
r
Location
Developer — WWF
Engineer/Arch.
Dist. Office
F NF
DISTRIBUTION
Dist. Engineer
Geologist
Soils Engineer
I Goo. Group File
Grading Section
Health Dept.
Engineer
Review of:
Zo--tradi ng P.C. No. Building P.C. No. For:
Geologic Report(s) Dated
Soils Report(s) Dated
7 Geology and Soils Report(s) Date; 9—
To t 6RRt>1Ny--->
Action: Plan is geologically approved. Van is not approrvedirf-
4.;
raso"
Plan approved geologically subject
ns b6low.
7e'LU NIT PLANS FOR RECHECK. Include a cgU
to condons below. of this review.
Remarks:
I. JZA consulting, ?e`nglneering geology, engineering p>ort, ) Is requir''e`dw'h-tch evaluate(s)
this specific plan, and make(s) recommendations. 'So,& ar
re;
GEOTECHNICAL ENGINEERING REVIEW SHEET
COUNTY OF LOS ANGELES District Office 10
Address: 900 So. Fremont Ave. DEPARTMENT OF PUBLIC WORKS
Alhambra, CA 91803
Telephone: (818) 458-4925 Land Development Division Sheet 1 of 1
4,q 3f7 f '
DISTRIBUTION:
E
Proposed Single Family Residence
Location 22105 Rim Fire Lane Diamond Bar / Grading and Drainage Sect.
Developer/Owner Cochran T Geo/Sails Central File
Geotechnical Engineer Triad Foundation Engineering Geologist
Geologist Same as above L Geotechnical Engineer
Engineer
District Engineer
Grading Plan Check No. 0861
Review of:
Geotechnical Report dated 3/21/89 Geologic Report dated 3/21/89
Action:
Before approval the following information is required:
Remarks:
1. Provide preliminary soil report dated 9/8/88.
2. Provide grading plans including detail sections of proposed buttress fills, crib
walls, and fill benches.
Provide slope stability analyses for the out -dipping slopes shown on Sections A -A' and
B -B' of the geotechnical report.
4. The Geotechnical Engineer must review the grading pians and sign and stamp the plans
in verification of his recommendations and the recommendations of the approved
geotechnical report.
5. Add the following notes on the grading plans:
The Geotechnical Engineer shall inspect and approve the foundation excavations before
steel or concrete is placed.
6. Please include a copy of this review sheet with your response.
Prepared by
Paul ChangChang
F:0859
9
Reviewed by '' e,(..pate 5/18/89
Victor C. Martinez
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a- TRIAD FOUNDATION ENGINEERING, Inc,
Consulting Geologists — Soils Engineering
Job no: Date: - Scalo: By:
TEST PIT LOG
Project 22105 Rim Fire -Diamond Bar Teat Pit No.2 Location see geologic mala
Job No. 88-494 Drill Date 6-13-89 Logged By JLK Driving Weight __-
in
UNIT (FILL, NATURAL, BEDROCK, etc.) : 1.4
MATERIAL (SAND, SILT, CLAY, etc.) -
vs 0 1
u 0
Description (color, moisture, density, etc.) w c, 0
a
o w ATTITUDE MEASUREMENTS :p, u
c w u
W
B - Bedding F - Fault p 0 4 U an
320 J - Joint C - Contact A ca
TOPSOIL: Clayey SILT with Sand - dark -brown, moist ML
very firm, moderately porous
2
of
BEDROCK: SANDSTONE - Fine to Coarse Grained, light
gray with orange -brown clasts, dense,
4 moderately weathered & friable
5
C N75E 20NW - irregular contact - indistinct
6 SANDSTONE - Fine grained, light gray, dense,
well cemented - difficult to excavate
7
Rock is moderately to thickly bedded with no
distinct bedding plane surfaces
J N85E 62SE
9
10 END OF TEST PIT 8.5 FEET
No Ground Water or Caving
11
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1415
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15-
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TEST PIT LO
Project 22105 Rim Fire -Diamond Bar Test pit No. 3 Location see geologic map
Jab No. 88-494 Drill Date 6-13-89 Logged By JLK Driving Weight ---
i niew r5unu 1 ium C1Mumm1nu, inn. rL.AI t B-3
UNIT (FILL, NATURAL, SEDR , etc.) : Z ...
MATERIAL (SAND, SILT, CLAY. etc.) - A m y
4J 0,m
Description (color, moisture, density, etc.)
U w p 2
3 G wATTITUDE is 4V
B - Bedding F - Fault 4
280 J - Joust G - Contact
0 TOPSOIL: Clayey SILT with Sand - dark -brown, ML
slightly moist, very firm, trace to slightly
1 porous
More Sand, brown
2 BEDROCK: Interbedded SILTSTONE & Fine Grained
SANDSTONE - gray & brown, dense, moderately
weathered & fractured
B NlOE 18NW - on irregular surface
4—
Shear N2OW 57SW
S Slightly weathered, difficult to excavate
Little or no fracturing
W
7
END OF TEST PIT 6.5 FEET
No Ground Water or Caving
10—
11-
12- 12
1313-
14- 14
1515
MPI%aA0% aftsearir...ir.r............"""..W._......__...... _
i niew r5unu 1 ium C1Mumm1nu, inn. rL.AI t B-3
TEST PIT LO
Project 22105 Rim Fire -Diamond Bar Test Pit No. 4 Location see geologic map
lob No. 88-494 Drill Dene 6-13-89 Logged By JLK Driving Weight ---
i nimu FOUNDA 1 IUN tnuinteminu, IAC. FL.A1 k B-4
UNIT (FILL, NATURAL, BEDROCK, etc.) :
MATERIAL (SAND, SILT, CLAY. etc.) - y Zy
Description (color, moisture, density, etc.) w a ii
A w ATTITUDE MEASURMCNTS:p, U1 4
B- Bedding F- Fault 0 c A U 0 G260J - Joint C - Contact t0
Q
TOPSOIL: Sandy SILT with Clay - dark -brown, ML
slightly moist, very firm, trace to slightly
1 porous
BEDROCK: SANDSTONE - Fine to Coarse Grained -
light gray with orange concretions, dense,
2 moderately weathered & friable
4
aneof Min SiTtstane un3.ts
B N60E 21NW
Fine Grained SANDSTONE - slightly weathered, well
cemented, difficult to excavate
6
7
END OF TEST PIT 6.5 FEET
No Ground Water or Caving
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