HomeMy WebLinkAboutPD 2020-0042; 4100 SUNNYHILL DRIVE; FINAL SOILS REPORT; 2022-01-13January 13, 2022
Project No. 9235.1
Log No. 21737
Ron Severino
3295 Pio Pico Drive
Carlsbad, California 92008
Subject: AS-BUILT GEOTECHNICAL LETTER
Retaining Wall
4100 Sunny Hill Drive
Carlsbad, California
References: 1) “Geotechnical Investigation, Proposed Retaining Wall, 4100 Sunny
Hill Drive, Carlsbad, California”, by Hetherington Engineering, Inc.,
dated November 25, 2020.
2) “Response to City of Carlsbad Review, Proposed Retaining Wall, 4100
Sunny Hill Drive, Carlsbad, California,” by Hetherington Engineering,
Inc., dated January 13, 2021.
3) “Grading Plans for 4100 Sunny Hill Drive, Lot 80 Carlsbad Highlands
No. 2, GR2020-0034,” prepared by Alidade Engineering, Inc., dated
April 16, 2021.
Dear Mr. Severino:
In accordance with your request, we have performed geotechnical observation and testing
of the retaining wall construction at the subject site (see attached Field Reports). The
construction consisted of the demolition and removal of an existing retaining wall, and
construction of a new 30-inch high CMU block retaining wall along the west and north
property lines at the subject site.
Foundation excavations for the retaining wall were observed by an engineer from this
office. Footings were founded into suitable paralic deposits as recommended and
dimensioned in accordance with the grading plans (Reference 3). The retaining wall was
provided with a backdrain consisting of 4-in diameter, Schedule 40 perforated pipe
surrounded by approximately 1-cubic-foot per lineal foot of 3/4-inch crushed rock, all
wrapped in filter fabric. 3/4-inch crushed rock was placed from the top of the backdrain to
6-inches below finish grade in 6 to 8-inch thick, near horizontal lifts and compacted by
mechanical means to a minimum of 90-percent relative compaction as determined by
ASTM: D 1557.
SOIL & FOUNDATION ENGINEERING ENGINEERING GEOLOGY HYDROGEOLOGY
(760) 931-1917 Fax (760) 931-0545
333 Third Street Laguna Beach, CA 92651 (949) 715-5440 Fax (949) 715-5442
Carlsbad, CA 92008-43695365 Avenida Encinas, Suite A
HETHERINGTON ENGINEERING, INC.
www.hetheringtonengineering.com
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AS-BUILT GEOTECHNICAL LETTER
Project No. 9235.1
Log No. 21737
January 13, 2022
Page 2
Geotechnical aspects of construction were performed in accordance with the
recommendations in the “Geotechnical Investigation…” (Reference 1) and the
requirements of the City of Carlsbad.
This opportunity to be of service is sincerely appreciated. If you have any questions, please
call this office.
Sincerely,
HETHERINGTON ENGINEERING, INC.
Edwin R. Cunningham Mark D. Hetherington
Civil Engineer 81687 Civil Engineer 30488
(expires 3/31/22) Geotechnical Engineer 397
(expires 3/31/22)
Distribution: 3-Addressee
1-via e-mail (ronseverino44@gmail.com)
1-via e-mail (Tim.Stanton@carlsbadca.gov)
HETHERINGTON ENGINEERING, INC.