HomeMy WebLinkAboutCDP 2020-0001; PATEL RESIDENCE; RESPONSE TO THIRD PARTY GEOTECHNICAL REVIEW FOR PROPOSED TWO-STORY RESIDENCE WITH BASEMENT GARAGE; 2021-02-17Mr. Rajesh Patel
3170 Vista Way
EAST COUNTY SOIL CONSULTATION
AND ENGINEERING, INC.
10925 HARTLEY ROAD, SUITE "I"
SANTEE, CALIFORNIA 92071
TEL. 619-258-7901
Oceanside, California 92056
February 17, 2021
Project No. 19-l 126G3
Subject: Response to Third-Party Geotechnical Review for Proposed Two-Story
Residence with Basement Garage
5462 Carlsbad Boulevard
Carlsbad, California 92008
Reference:
• Third Party Geotechnical Review (Third) for Proposed Single Family Residence, Carlsbad
Boulevard, Carlsbad, California, Project No. ID: CDP 2020-0001 , by Hetherington
Engineering Inc, dated January 25, 2021
Dear Mr. Patel:
In accordance with your request, we have prepared this letter in response to the subject third-
party geotechnical review by Hetherington Engineering, Inc.
Comment Nos. 1 and 2
Please find attached (Figures No. 2 and 3) showing an updated geotechnical map/plot plan and
geologic cross sections.
Comment No. 3
It is our opinion that the proposed grading and construction will not adversely impact the adjacent
properties or improvements.
Comment Nos. 4 and 5
Proposed driveway and exterior concrete slabs should be at least 5 inches thick and reinforced
with No. 4 rebars spaced at 18 inches on centers in two directions and placed at mid-height in the
slab. Exterior slabs should be supported on the exisitssng souls scarified to a depth of 6 to 8
inches inches, moisture condititoned and compacted to at least 90 percent relative compaction.
Driveway and exterior slabs should be provided with construction joints spaced no more than 1 O
feet apart to minimize shrinkage cracking. Slab concrete should have a minimum compressive
Response to Third-Party Geotechnical Review for Proposed Two-Story Residence
with Basement Garage
5462 Carlsbad Boulevard
Carlsbad, California 92008
Page 2
February 17, 2021
Project No. 19-1126G3
strength of 3,000 psi and maximum water-cement ratio of 0.5 to minimize shrinkage cracking. No
special testing of concrete is necessary. Some shrinkage cracking is still possible.
Comment No. 6
An allowable passive pressure for foundations of 300 pounds per cubic foot may be used. Section
1806.2 of the 2019 CBC allows 400 pcffor sedimentary rock.
Comment No. 7
Corrosivity tests were performed on a representative sample of the onsite soils. The attached test
results (Figure 4) indicate a low degree of corrosivity.
Accordingly, we recommend Type I/II Portland Cement for foundation construction.
Comment No. 8
The project geotechnical engineer or engineer's representative should receive advance notice to
provide the necessary intermittent fieled observations and compaction testing during site
development.
Comment No. 9
The attached Figure 1 provides an updated list of references.
This opportunity to be of service is appreciated. If you have any questions, or we can be of
further service, please do not hesitate to call or contact us .
This opportunity to be of service is appreciated. If you have any questions, or we can be of
further service, please do not hesitate to call or contact us.
Respectfully Submitted,
Martin R. Owen, PE, GE
Geotechnical Engineer
Attachments: Figures 1 through 4
EAST COUNTY son, CONSULTATION AND ENGINEERING, INC.
Response to Third-Party Geotechnical Review for Proposed Two-Story Residence
with Basement Garage
5462 Carlsbad Boulevard
Carlsbad, California 92008
FIGURE 1
REFERENCES
Page 6
February 17, 2021
Project No. 19-1126G3
1. "2019 California Building Code, California Code of Regulations, Title 24, Part 2, Volume 2 of 2",
Published by International Code Council.
2. "Grading Plans for Patel Residence-Terramar, Carlsbad Boulevard, Project No. CDP 2020-0001,
Drawing No. 526-6A, Prepared by BHA, Inc. Land Planning, Civil Engineering, Surveying, Undated.
3. "Response to Third-Party Geotechnical Review for Proposed Single-Family Residence with
Basement Garage, 5462 Carlsbad Boulevard, California 92008, Project No. I 9-l 126G3, Prepared by
East County Soil Consultation and Engineering, Inc., Dated January 13, 2021.
4. "Review of Grading Plans and Supplemental Geotechnical Recommendations, Proposed Single-
Family Residence, 5462 Carlsbad Boulevard, California 92008, Project No. I 9-l l 26G3, Prepared by
East County Soil Consultation and Engineering, Inc., Dated November 11, 2020.
5. "Review of Foundation Drawings, Plans and Details for Proposed Single-Family Residence, Carlsbad
Boulevard, APN 210-115-08, Project No. I 9-l l 26G3, Prepared by East County Soil Consultation
and Engineering, Inc., Dated October 24, 2020.
6. "Response to EsGil Review, Proposed Single-Family Residence, 5462 Carlsbad Boulevard, Carlsbad,
California 92008", EsGil plan Check No. PC2020-0040, Project No. I 9-l l 26G3, Prepared by East
County Soil Consultation and Engineering, Inc., dated October 17, 2020.
7. Updated Report of Geotechnical Investigation for Proposed Single-Family Residence (Patel
Residence), 5462 Carlsbad Boulevard, APN 210-115-08, Carlsbad, California 92008, Project No. 19-
l 126G3, Prepared by East County Soil Consultation and Engineering, Inc., Dated January 12, 2021.
EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC.
Second Response to Third-Party Geotechnical Review for Proposed Two-Story
Residence with Basement Garage
5462 Carlsbad Boulevard
Carlsbad, California 92008
FIGURE2
GEOTECHNICAL MAP
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Page4
February 14, 2021
Project No. 19-1126G3
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Second Response to Third-Party Geotechnical Review for Proposed Two-Story
Residence with Basement Garage
Page5
February 14, 2021
Project No. 19-l 126G3
5462 Carlsbad Boulevard
Carlsbad, California 92008
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EAST COUNTY SOIL CONSULTATION AND ENGINEERING, lNC.
Second Response to Third-Party Geotechnical Review for Proposed Two-Story
Residence with Basement Garage
5462 Carlsbad Boulevard
Carlsbad, California 92008
FIGURE4
pH-RESISTIVITY TEST RESULTS
L A B O R A T O R Y R E P O R T
Page 6
February 14, 2021
Project No. 19-l 126G3
Telephone (619) 425-1993 Fax 425-7917 Established 1928
CLARKSON LABORATORY AND SUPPLY INC .
350 Trousdale Dr. Chula Vista, Ca. 91910 www .clarksonlab .com
A N A L Y T I C A L A N D C O N S U L T I N G C H E M I S T S
Date : February 3 , 2021
Purchase Order Number : NONE
Sales Order Number : 50602
Account Number: EASCS
To :
*-------------------------------------------------*
East County Soil Consultation and Engineering Inc .
10925 Hartley Road Suite I
Santee, Ca 92071
Attention: Michael Duncan
Laboratory Number: SO8103 Customers Phone : 258-7901
Fax : 258-7902
Sample Designation:
*-------------------------------------------------*
One soil sample received on 01/29/21 at 12:30pm,
taken from Patel Carlsbad Blvd.
Analysis By California Test 643, 1999, Department of Transportation
Division of Construction, Method for Estimating the Service Life of
Steel Culverts .
pH 7 .1
Water Added (ml)
46
60
84
107
130
10
5
5
5
5
5
5
years
years
years
years
years
to perforation
to perforation
to perforation
to perforation
to perforation
for a
for a
for a
for a
for a
Water Soluble Sulfate Calif.
Water Soluble
Rosa Bernal
RMB/arr
Chloride Calif .
16 gauge metal
14 gauge metal
12 gauge metal
10 gauge metal
8 gauge metal
Test 417
Test 422
Resistivity (ohm-cm)
30000
25000
20000
20000
20000
21000
22000
culvert.
culvert.
culvert.
culvert.
culvert.
<0 .003%
0.004%
EAST COUNTY SOIL CONSULTATION AND ENGINEERING, INC.