HomeMy WebLinkAboutSDP 15-10; CARLSBAD OAKS NORTH BUSINESS PARK LOT 13; SOIL NAIL WALL PLAN REVIEW AND GLOBAL STABILITY ANALYSIS; 2016-01-18GEO CON
INCORPORATED
GEOTECHNFcAL 1 ENVIRONMEN,TA:L • MATERIALS
Project No. 06442-32-20
January 18, 2016
SR22 Carlsbad Oaks Distribution, LLC
% SR Commercial
127 Lomas Santa Fe Drive
Solana Beach, California 92075
Attention: Mr. Adam Robinson
Subject: SOIL NAIL WALL PLAN REVIEW AND GLOBAL STABILITY ANALYSIS
CARLSBAD OAKS NORTH BUSINESS PARK - LOT 13
CARLSBAD, CALIFORNIA
References: 1. Permanent Soil Nail Walls, Tier 1, Tier 2, Tier 3-1 & Tier 3-2, Carlsbad Oaks
Lot 13, Carlsbad, California, prepared by Drill Tech Drilling and Shoring, Inc.,
PDF copy received October 15, 2015.
2. Update Geotechnical Report, Carlsbad Qaks North Business Park - Lot 13,
Carlsbad, California, prepared by Geocon Incorporated, dated March 18, 2015.
Dear Mr. Robinson:
In accordance with your request, we have reviewed the retaining wall plans for the Carlsbad Oaks
North Business Park - Lot 13 project. The purpose of our review was to check that the plan and
details have been prepared in substantial conformance with the recommendations presented in the
referenced project geotechnical report. In addition, we performed a global slope stability analysis for
the proposed soil nail wall.
Based on our review, it is our opinion that the wall plan and details have been prepared in substantial
conformance with the recommendations presented in Reference No. 2.
We utilized the computer program GeoStudio 2007 distributed by Geo-Slope International to perform
the slope stability analysis. This program uses conventional slope stability equations and a two-
dimensional limit-equilibrium method to calculate the factor of safety against deep-seated failure. For
our analysis, Spencer's Method with a circular failure mode was used. Spencer's Method satisfies
both moment and force equilibrium. We used the shear strength parameters presented in Reference
No. 2. These shear strength values are shown on Figures 1 and 2 (attached herein).
We used Special Publication 117A guidelines adopted in 2008 by the California Geologic Survey
(CGS) for evaluating static and seismic slope stability. An equivalent site acceleration, kEQ, of 0.15g
was used to perform the seismic slope stability analysis.
Based on our slope stability analyses, the proposed soil nail retaining wall exhibits a minimum factor
of safety of at least 1.5 and 1.0 for static and seismic loading, respectively, and is considered grossly
6960 Flanders Drive 0 SOn DiegO, California 921212974 0 Telephone 85.558.6900 U Fax 858.558.6159
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Attachments: Figures 1 and 2.
EA:DBE:dmc
Addressee
Excel Engineering
Attention4 Mr. Andrew Van Loy
TFW Construction
Attention: Mr. Ted Weeks IV
stable as designed. This opinion assumes that the recommendations presented in the referenced report
are implemented during construction. The results of the slope stability analyses are presented in
Figures 1 and 2.
Our plan review was limited to geotechnical aspects of project development and did not include the
review of other details on the referenced plan. Geocon Incorporated has no opinion regarding other
details found on the referenced plan, structural, civil, or otherwise, that do not directly pertain to
geotechnical aspects of site development.
If you have any questions regarding this correspondence, or if we may be of further service, please
contact the undersigned at your convenience.
Very truly yours,
GEOCON INCORPORATED
David 4B. )t
CEG 1860 -
DAVID B.
EVANS
NO. 1860
CERTIFIED
ENGINEERING
GEOLOGIST,
Project No. 06442-32-20 -2- January 18, 2016