HomeMy WebLinkAboutm28853.pdf2131 881-2063 881 -
2076 M)
MMC4)c, W1, i M'LL c. P. c engineering
geologist APR 2 21968 18Q32
TOPHAM STREET TARZANA,
CALIF 91356 --- April
40 1963 D U L5 D APR
12 190 Engineering
Geologic Review TRI STATE LLTCO. Borrow !area for
Tract 3 3 FUI.i.ERTOERkNG fV Diamond Bar, Los
Angeles County Project 7233 H.
V. Lae
aster and Company 7940 iAlairi Street
ENGINEER NUG GEOLOGY Stanton, California SECTION
Gentlemen: Please
be
advised
that the grading plan for the borrow area for Tract
28853 has been, examined by the writer. It reduces the helj7ht
of a "temDorary" out slope, by striDAing shale, mudstone, and
a minor volume of conglomerate. There will be
no reduction in gross stability of the existing cut, nor
is the proposed cut erected to be subject to more than
minor deterioration through ravelling, erosion, and slaking. Very
truly ,yours,
John D. Merrill
Engineering Geologist JIN:
ng
engineering geologist
18432 TOPHf.M STREET
TARZANA. CAOF 91356
July 8, 1968
REPLY ACTw _.r1100 ,,,.,
JUL 1 01968
0 1 1',
1 ' R::1s i EPIY Grading Plan ReviewENGINEERING a ' Tract ?7538 .'_,
Diamond Bar
SECTIONLosAngelesCounty
Project 7233
H. V. Laimaster and Company
7940 Main Street
atanton, California
Gentlemen:
Th:i,s letter is to advise you that the grading Man for
Tract 27538, dated 13 May 1968, prepared by Tri-State Engineer-
ing Company, Fullerton, California, has been revieved by the
Triter. Elements given specific consideration include the
detailed buttress fill design .for lots 14 through 17: and the
stabilization fill behind lots 79 to 79. In addition, the soil
engineer's laboratory tent criteria for design of the buttress
fill was disouseed fully. In of the straightforvard
geologic parameters it has been concluded that the design is
conservative, and therefore, should provide an adequate factor
of safety.
It is proposed to construct a combination block wall
and chain link fence, per Los Angeles County Engineering Standard
Plan D63, along the toe of future cutslopes bordering the north-
west and northeast sides of the tract. It is understood that
the awls will be constructed to support about three feet of
bedrock, leaving about one foot of freeboard at the top to
provide debris control.
Locally, the cutslopes will rise more than 30 feet above
the wall without drainage control devices. This design is
programmed largely in cut areas where debris production will
be slight o Ing to the hard, competent nature of the conglom-
erate bedrock. Moreover, for :call design purpose the con-
glomerate should be considered to be homogenous rock that
JDHN D. MERRILL
EMOOP4EFRING f3KOLOGIST
rro ject 72_51) - Page `''
possesses no planar features along which high stresses are
directed onto the proposed walls. Other factors of wall design
should be considered by the design engineer, based upon soil
engineering parameters.
During the oourse of grading, frequent checks by the
geologist will be performed to insure that no unusual or haz-
ardous geological condition has been exposed. Appropriate
rccommenda,tions for remedial grading will be presented if nec-
essary,
From an engineering geologic standpoint the grading
plan of Tract 27538 is approved as being consistent with the
recornmendations of the engineering geologic report for the
Tract dated 3 June 196,8. -
Very truly yours,
John D. Merrill
Engineering Geologist
JDK : ng