HomeMy WebLinkAboutCDP 05-46; MOSS RESIDENCE; UPDATE TO REPORT OF GEOTECHNICAL INVESTIGATION; 2018-02-08SHEI Geotechnical Exploration, Inc.
SOIL AND FOUNDATION ENGINEERING 0 GROUNDWATER e ENGINEERING GEOLOGY
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08 February 2018
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Mr. Steven H. Moss FEB 13 2M Job No. 07-9342
25408 Colette Way
Calabasas, CA 91302 LAND DEVELOPMENT
Subject: Update to Report
Proposed Moss Residence
5015 Tierra del Oro Street
Carlsbad, California
Dear Mr. Moss:
As requested, we herein provide this update to our original "Report of Geotechnical
Investigation and Geologic Reconnaissance" dated April 20, 2007. As part of this
update report, we have included updated seismic design criteria and reviewed to
temporary slope recommendations included in our report and the potential need for
shoring.
We visited the property to observe the current site conditions and discussed the
proposed project plans as compared to the original plans that were reviewed by our
firm during our investigation. It should be noted that the site has not changed
significantly since the project was approved, and there has been no change in
specific circumstances related to the underlying soil and geologic conditions.
No additional grading is proposed beyond what was originally proposed as part of
the approved project. Based on our review of the proposed basement excavation
requirements, it is our opinion that shoring will not be required. Temporary slopes
up to 9 feet will be required, including vertical cuts in the lower 4 feet into dense
formational soils and 0.75:1.0 to 1.0:1.0 in the upper 5 feet into existing fill soils.
7420 TRADE STREETS SAN DIEGO, CA. 92121 0 (858) 549-7222S FAX: (858) 549-1604 0 EMAIL: geoteth@gei-sd.com
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Proposed Moss Residence Job No. 07-9342
Carlsbad, California Page 2
Site-specific seismic design criteria to calculate the base shear needed for the
design of the residential structure are presented in the following table. The design
criteria was obtained from the California Building Code (CBC) 2016 edition, and is
based on the distance to the closest active fault and soil profile classification.
The proposed structure should be designed in accordance with Section 1613
of the 2016 CBC, which incorporates by reference the ASCE 7-10 for seismic
design and the following parameters should be utilized. We have determined
the mapped spectral acceleration values for the site based on a latitude of
33.1331 degrees and longitude of 117.3369 degrees, utilizing a program
titled "Design Maps and Tools," provided by the USGS, which provides a
solution for ASCE 7-10 (Section 1613 of the 2016 CBC) utilizing digitized files
for the Spectral Acceleration maps.
In addition, we have assigned a Site Classification of D. The response
parameters for design are presented in the following table. The design
spectrum acceleration vs. Period T is attached.
TABLE I
Mapped SDectral Acceleration Values and Design Parameters
I s, Is, I Fa I Fy I Sms I Smi I Sd5 Sd1
1.1769 10.4529 11.030 11.548 11.2119 1 0.699g I0.807g 0.466g
LIMITATIONS
The findings, opinions and conclusions presented herein have been made in
accordance with generally accepted principles and practice in the field of
geotechnical engineering within the City of Carlsbad. No warranty, either
expressed or implied, is made.
Proposed Moss Residence Job No. 07-9342
Carlsbad, California Page 3
If you have any questions regarding this letter, please contact our office. Reference
to our Job No. 07-9342 will help expedite a response to your inquiry.
Respectfully submitted,
GEOTECHNICAL EXPLORATION, INC.
Jaime A.," C , .
34422/G.E. 2007
SeQior Geotechnical Engineer
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r1H eiser
Senior Project Geologist
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1/152018 Design Maps Summary Report
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User-Specified Input
Report Title 5015 Tierra Del Oro, Carlsbad, CA
Mon January 15, 2018 21:13:59 UTC
Building Code Reference Document ASCE 7-10 Standard
(which utilizes USGS hazard data available in 2008)
Site Coordinates 33.133080N, 117.33687°W
Site Soil Classification Site Class D - "Stiff Soil"
Risk Category I/Il/Ill
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USGS—Provided Output
S5 = 1.176g S= 1.2119 SD5 = 0.807g
S1 = 0.452 g SM1 = 0.699 g SDI = 0.466 g
For information on how the SS and Si values above have been calculated from probabilistic (risk-targeted) and
deterministic ground motions in the direction of maximum horizontal response, please return to the application and
select the "2009 NEHRP" building code reference document.
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For PGA,, TLI C, and C5 values, please view the detailed report.
Although this information Is a product of the U.S. Geological Survey, we provide no warranty, expressed or implied, as to the
accuracy of the data contained therein. This tool is not a substitute for technical subject-matter knowledge.
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