HomeMy WebLinkAboutPD 2022-0003; KEMPER RESIDENCE; RESPONSE TO COMMENTS -FOUNDATION AND SLAB CRITERIA; 2022-08-25ALLIED EARTH TECHNOLOGY
7915 SILVERTON AVENUE, SUITE 317
SAN DIEGO. CALIFORNIA 92126
PH. (858) 586-1665 FAX (858) 586-1650
(6 I 9)44 7-474 7
ROBERT CHAN. P.E.
City of Carlsbad
Land Development Engineering
1635 Faraday Avenue
Carlsbad, CA/ 92008
August 25, 2022
Subject: Project No. 21-1127C6
Kemper Residence
7133 Aviara Drive
Carlsbad, California
Gentlemen:
The following is response to City comments :
1. Foundation and slab design criteria for expansive soils should be consistent with Section
I 808. 6 of the 20 I 9 California Building Code. The consultant should update foundation
recommendations, as necessary based on expansion index test data. (repeat comment -
As soils with expansion index (El) over 20 are considered expansive and require mitigation
in accordance with Section 1803.5.3 and 1808.6 of the 2019 CBC, please clarify the
methods that are being recommended to address expansive soils, and provide an statement
that the proposed foundation system for the residence will meet the requirements of Section
1808.6 of the 2019 California Building Code.
In order to minimize the detrimental effects of the expansive soils on foundation and slab,
it is recommended that the continuous footings for the proposed structure be reinforced
with a minimum of 4 #5 rebars; two rebars located near the top, and the other two rebars
near the bottom of the footings. All isolated pier footings should be reinforced with a
inimum of2 #5 rebars in both directions, placed near the bottom of the footings.
The concrete slab-on-grade should be 4 ½ inches in thickness, and be reinforced with #3
rebars @ 18 inches on center in both directions, placed at mid-height of concrete slab. The
concrete slab should be underlain by 4 inches of clean sand, a 10-mil moisture barrier and
covered by another inch of clean sand.
Project No. 21-1127C6 Steve Kemper 07/01/22
7133 Aviara Drive
The proposed foundation and slab system, designed as recommended above will meet the
requirements of Section .6 of the 2019 CBC.
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No. G-00198
Exp. 12/31/l:3
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