HomeMy WebLinkAboutPD 2022-0007; HAGUE RESIDENCE; SOILS REPORT-RESPONSE TO COMMENTS; 2022-09-06
EDG Project No. 216614-1
Date: September 6th, 2022
To: Ms. Nichole Fine
City of Carlsbad
Land Development Engineering
1635 Faraday Avenue
Carlsbad, California 92008-7314
Re: Proposed new, single-family residence, to be constructed at Cynthia Lane (APN:156-231-
70), Carlsbad, California
Subject: Addendum No. 2 – Updated Recommendations and Response to Comments.
EDG Project: 216614-1
Project ID: PD2022-0007
Grading No. GR2022-0011
References:
1. “Preliminary Geotechnical Investigation and Recommendations Proposed, New Single-Family
Residence to be located at Cynthia Lane (APN:156-231-70), Carlsbad, California”, prepared by
Engineering Design Group, dated October 18th, 2021.
2. “Addendum No. 1 – Updated Recommendations and Response to Comments”, prepared by
Engineering Design Group, dated August 26, 2022.
3. Geotechnical Report Review, Hague Residence – Cynthia Lane, Carlsbad, California (2nd Review),
dated August 5, 2020. From City of Carlsbad – Land Development Engineering.
4. Engineering Design Group, Grading Plan for Hague Residence– APN: 260-213-13, dated August
2022.
1.0 PURPOSE
We have prepared this addendum to provide updated recommendations to the above referenced
preliminary geotechnical report and addendum No. 1 (Reference No. 1 and No. 2, respectively) based
upon the updated preliminary grading plans (Reference No. 4), for the proposed new, single-family
residence, to be located at Cynthia Lane (APN: 156-231-70), in the City of Carlsbad. This addendum will
ENGINEERING
DESIGN GROUP
www.designgroupca.com
2121 Montiel Road, San Marcos, CA 92069
760.839.7302
EDG Project No. 216614-1
also address City of Carlsbad – Land Development Engineering Department’s – Geotechnical Report
Review comments (Reference No. 3). The response to comments will be incorporated into this
Addendum.
2.0 GEOLOGY AND FAULTS – RESPONSE TO COMMENT NO. 1
As described in Addendum No. 1, the project site is located within the Peninsular Ranges Geomorphic
Province of California. Site area topography consists of coastal foothill terrain and relatively shallow
drainages. The site is underlain by late-to-middle, Pleistocene-era, paralic deposits (as mapped per
Kennedy, et.al., 2007).
The nearest mapped active fault (Holocene) is the Rose Canyon Fault (Newport-Inglewood Fault zone) in
the Offshore Zone of Deformation, located approximately 22 miles southwest of the subject site. Other
major mapped faults in the region are the Elsinore Fault and associated faults within the Elsinore zone,
and the San Jacinto Fault and related branches within the San Jacinto zone. The subject site is
approximately 24 miles southwest from the Elsinore Fault zone and approximately 48 miles west from the
San Jacinto Fault zone.
Our review of geologic literature pertaining to the general site area indicates the subject site is not within
a mapped Alquist-Priolo fault zone. It is our opinion that the site could be subjected to moderate to severe
ground shaking in the event of a major earthquake along any of the faults in the Southern California
region. The seismic risk at this site is similar to that of the surrounding developed area.
3.0 SOIL TYPE AND VALUES – RESPONSE TO COMMENT NO. 2
During our subsurface investigation, penetrometer readings were taken within our test pits. Readings
from our tests, indicate onsite soils posses an unconfined compressive strength of between 2.0 and 3.0
tons per square foot. Based upon onsite testing, observation of onsite soils and our experience, a
conservative value of 2,000 PSF for bearing capacity was provided in our original report.
4.0 SITE CLASS – RESPONSE TO COMMENT NO. 3
For clarification purposes, we have provided the following values corresponding to Site Class D.
Site Class D*
Seismic Design Category D*
ASCE 7-16 Seismic Design Parameters
SS (g) 1.048
S1 (g) 0.381
SMS (g) 1.133
EDG Project No. 216614-1
SDS (g) 0.755
*Using the code values provided in the table above rather than
performing a ground motion hazard analysis, requires the exception
identified in ASCE section 11.4.8 be utilized in the structural design.
All recommendations and design parameters from our original report, not discussed herein, remain
applicable. If you have any questions regarding this letter, please feel free to contact our office.
Sincerely,
ENGINEERING DESIGN GROUP
Erin E. Rist
RCE #65122
Steven Norris
GE 2590; CEG 2263
2590
Exp 12-31-23