HomeMy WebLinkAboutCT 02-28; LA COSTA CONDOMINIUMS; LANDSIDE STABILIZATION; 2008-04-09BUREAU
VERITAS
April 9, 2008 Contract No.: 148589
Mr. Steve Bobbett
City of Carisbad-Public Works
1635 Faraday Avenue
Carisbad, CA 92008
Subject: Third-Party Review of Construction Revision
Landslide Stabilization
Banich, Powers, Calso Landslide
2416 Sacada Circle
Carisbad, California
Dear Mr. Bobbett:
Introduction
As requested, Bureau Veritas North America, Inc. has performed a third-party
geotechnical review of the construction revision for the subject project. The
purpose of our review was to provide an opinion on whether the geotechnical
aspects of the construction revision have been Identified and appropriately
addressed In the project geotechnical documents. This letter presents the
results of our third-party review. Our review is based on geotechnical data
presented In the project geotechnical documents and our professional
judgment. We have not performed a subsurface Investigation, laboratory
testing or Independent geotechnical analysis for the project. The following
project documents were provided for our review:
1. "Interim Repair Recommendations, Landslide Stabilization, Banich,
Powers, Calso Landslides, 2416 Sacada Circle, Carisbad, California,"
prepared by American Geotechnical, Inc., File No. 23080-02, dated
February 19, 2008.
2. "Landslide Stabilization Recommendations, Banich Powers, Calso
Landslides, 2416 Sacada Circle, Carlsbad, California 92009," prepared
by American Geotechnical, Inc., File No. 23080.02, dated March 27,
2007.
3. "Project Plans for Banich, Powers, Calso Landslide Stabilization," Sheets
1 to 6, prepared by American Geotechnical, inc., dated March 27, 2007.
Testing Engineers San Diego
.4 Bureau\'erilas Company Main: 858,715,5800
7895 Convoy Court. Suite'18 Fax: 858.715,5810
San Diego. CA 92111 www.us.bureauveritas.com
City of Carlsbad
Banich, Powers, Calso Landslide
Contract No.: 148569
Results of Review
Based on our geotechnical engineering review It Is our opinion that the
following comment should be addressed by the project geotechnical engineer
of record:
1. In reviewing Interim Repair Recommendations (see reference no. 1),
American Geotechnical, Inc. states In the third paragraph of Issue No. 2 that
"In terms of gross stability, the factor of safety is unchanged for the upper
part of the slope due to the support provided by the three tieback walls and
additional soil reinforcement." Since the slope ratio will change from 1.5:1
(horizontal to vertical) to 1.2:1, It Is unlikely that the factor of safety for the
gross slope stability will remain unchanged. In any case, the geotechnical
engineer of record should provide global slope stability analyses showing
that the factor of safety Is greater than 1.5 and 1.1 for the static and seismic
conditions, respectively.
The opportunity to be of service on this project is appreciated. If you have any
questions regarding our review, please contact our office.
Respectfully submitted,
Testing Engineers - San Diego, Inc.
A Bureau Veritas Company
Nick Tracy, EIT
Staff Engineer
Van Olin, PE, GE
Principal Geotechnica
Gene Custenborder, Cl
Senior Engineering Geologist
NT/GCA/0:cs
Distribution: (4) Addressee