HomeMy WebLinkAboutCT 2017-0007; TAMARACK BEACH HOMES; ADDENDUM TO LIMITED GEOTECHNICAL INVESTIGATION; 2018-09-17.. ~
~fr. Ben Ryan
EAST COUNTY SOIL C'ONSULTA TIOI\J
AND ENGlNEF:RING, INC.
10925 HARTLEY ROAD, SUITE ... ,,
SA~TEE, CALffORNIA 92071
(619) 258-7901
Fax (619) 258-7902
Tourmaline Properties
944 Archer Street
San Diego. California 92109
Subject: Addendum to Limited Gcotechnical investigation
five Proposed Single-Family Residences
438 Tamarack Avenue
City of Carlsbad, California 92008
September 17. 2018
Project No. 17-1106F6
Refer~ncc: .. Limited Gcotechnical Jnvestigat1on, Fi,e Proposed Single-Farnil} Residences, 438
·tamarack Avenue, City of C.:irbbad. California 92008". Project No. I 7-1106F6.
Prepared by East County Soil Consultation and Engineering. Inc .. Dated October 12.
2017.
Dear Mr. Ryan.
In accordance with your request, we hav1: prepared this addendum to address the proposed 3-foot
high (maximum) retaining wall at the subject sit~.
The proposed cantilevered retaining wall should be designed for an "active" lateral earth pressure of
35 psf/ft (35 pcf EFP) for approved granular and level backfill conditions. lf the wall is subject to
uniform sw·charge loads, it should be designed for an additional uniform lateral pressure equal to one-
third ( I /J) the anticipated surcharge pressure. This pressure is based on the backfill soils being free
draining mid non-expansive. Backfill materials mus1 be approved hy the soils engineer prior to use.
An additional lateral earth pressure due to earthquake motions of 26 pcf (Ef P) may be applied
using an inverted trian1:,:rular distribution if required.
Soil design criteria such as bearing capacity. passive earth pressure and sliding resistance us
recommended in the referenced geotechnkal repurt may be incorporated in the retaining wall
design.
RECORD COPY
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Initial Date LA,
OEC 10 20\8
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TOURJ1ALINE PROPERTIES ./38 TA.\1ARACK r-111£\'(;£ PROJECT.VO. !7-! !06/-6
Footings should be reinforced as recommended by the structural engineer and appropriate back
drainage provided to avoid cxcessi ve hydrostatic wall pressures. As a minimum, we recommend a
fabric:-v,-rapped crushed rock and perforated pipe system. At least 1 cubic feet per linear foot of free-
drainage crushed rock should be provideu. Waterproofing may include a sealer fluid ( fremco 250Gc
or equivalent) and a foam board.
Jf we can be of any further assistance. please do not hesitate to contact our office.
Respectfully submitted.
Mamadc,u Sahou ia o, P.E.
RCF 54071, GE 2704
MSD/md
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