HomeMy WebLinkAboutAttachmt 10 Stg 2 Rez Bklt - Appendix D
Via Facsimile and Mail
March 6, 2006
Job No. 1394.1 13A
Mr. Jim Tong
Charter Properties
4690 Chabot Drive, Suite 100
Pleasanton, California 94588
Subject:
Geotechnical Assessment of Commercial Development
Grafton Station at Dublin Ranch
Dublin Boulevard and Grafton Street
Dublin, California
Dear Mr. Tong:
At the request of Mr. Dave Chadbourne of MacKay & Somps, this letter provides our
geotechnical assessment of commercial development at Grafton Station at Dublin Ranch in
Dublin, California. Based on our discussion with Mr. Chadbourne, we understand that the
planned commercial development consists of 8 buildings with associated parking areas,
driveways and underground utilities, As part of a larger project, we previously performed three
geotechnical investigations at the site and its vicinity, and presented the results in the following
reports:
I, Geotechnical investigation report titled "Dublin Ranch, Assessment District, Infrastructure
Improvements, Tassajara Road and Fallon Road, Dublin, California," dated May 5, 1999
(BGC Job No, 1394.112).
2. Geotechnical investigation report titled "Dublin Ranch - Pao-Yeh Lin Property, Tassajara
Road, Dublin, California," dated August 30, 1999 (BGC Job No. 1394.1 13).
3, Geotechnical investigation report titled "Preliminary Geologic and Geotechnical
Investigation, Pao- Yeh Lin Property, Tassajara Road, Dublin, California," dated
November 13,1998 (BGC Job No. 1394.106).
During our previous investigations, we reviewed aerial photographs of the site and its vicinity,
pertinent geologic maps and available published reports; and performed geologic mapping of the
site. We also drilled a total of 12 borings to depths of about 25 to 50 feet to explore the soil and
groundwater conditions at the site and its vicinity. To evaluate the expansion potential,
settlement characteristics, liquefaction potential, shear strengths and corrosion potential of the
soil and engineered fill, we conducted 48 Atterberg Limits, 100 single-point consolidation/swell,
72 direct shear, 22 unconfined compression, 13 consolidation, 19 gradation, 8 compaction and 8
corrosion tests.
To evaluate the presence and absence of earthquake faults within the site, we reviewed pertinent
fault maps and aerial photographs of the site. No earthquake faults (active or inactive) are found
SOIL ENGINEERS. ENGINEERING GEOLOGISTS. 5587 SUNOL 80ULEVARD . PLEASANTON, CA 94566 . (925) 484-0220 . FAX: (925) 846-9645
March 6, 2006
Job No. 1394.113A
Page 2
within the site. In the vicinity of the site, the Mt. Diablo Thrust, Calaveras, Greenville and
Hayward faults lie about 3 miles north, 4 miles southwest, 8 miles northeast and 10 miles
southwest of the site, respectively. It is our opinion that, from a geotechnical engineering
standpoint, the nearby active faults do not preclude commercial development at the site.
As part of Area H of Dublin Ranch, the site was mass graded in 2003 under our observation and
testing, The results of our observation and testing are summarized in our April 28, 2004 report
(BGC Job No. 1394.329).
In summary, it is our opinion that, from a geotechnical engineering standpoint, the site is suitable
for commercial development. Our previous reports provide sufficient conclusions and
recommendations for site mass grading, and backbone roadway and underground utility
construction. Design-level foundation investigation/study should be performed to provide
specific conclusions and recommendations for the design and construction of the commercial
buildings and associated parking areas, driveways and underground utilities.
We trust this letter provides the information you require at this time. If you have any questions,
do not hesitate to call us.
Respectfully submitted,
ERLOGAR GEOTECHNICAL CONSULTANTS
, fA ~, l-
~!~~tiai
rincipal Engineer
E 2326, Exp. 12/31/07
PSL:jmb
Copies: Addressee (2)
MacKay & Somps (3)
Attention: Mr. Dave Chadbourne
wordlletters/I8695
BERLOGAR GEOTECHNICAL CONSULTANTS