HomeMy WebLinkAboutCUP 2018-0014; FIRE STATION NO. 2; RESPONSE TO REVIEW COMMENTS; 2021-06-28
5710 Ruffin Road | San Diego, California 92123 | p. 858.576.1000 | www.ninyoandmoore.com
June 28, 2021 Project No. 108715014
Mr. Steven Stewart
City of Carlsbad – Public Works 1635 Faraday Avenue Carlsbad, California 92008
Subject: Response to Review Comments Carlsbad Permanent Fire Station No. 2 1906 Arenal Road Carlsbad, California
Dear Mr. Stewart:
At your request, we have prepared this letter providing responses to the referenced third party review
comments prepared by Hetherington Engineering on the geotechnical evaluation reports for the project
(Ninyo & Moore, 2017 and 2021). The comments and our responses are provided below.
Comment 1: The Consultant should review the project grading and foundation plans, provide any additional geotechnical recommendations considered necessary, and confirm that the plans have
been prepared in accordance with the geotechnical recommendations provided in the referenced reports.
Response: Our review of the project grading and foundations plans are provided under separate cover.
Comment 2: The Consultant should provide an updated geotechnical map/plot plan utilizing the
latest grading plan for the project to clearly show (at a minimum) a) existing site topography, b) proposed structures/improvements, c) proposed finished grades, d) locations of the subsurface
exploration, e) geologic contacts, and f) remedial grading limits, etc.
Response: The requested updated geotechnical map is presented on the attached Figure 1.
Comment 3: The Consultant should provide geologic cross-sections utilizing the current grading plan to clearly show (at a minimum) a) existing site topography, b) proposed structures/improvements,
c) proposed finished grades, d) geologic contacts, e) geologic structure, f) locations of the subsurface
exploration, g) temporary construction slopes and h) remedial grading, etc.
Response: The requested updated geologic cross section utilizing the current grading plan (BWE, 2021)
is presented as A-A’ on the attached Figure 2.
Geotechnical & Environmental Sciences Consultants
Ninyo & Moore | 1906 Arenal Road, Carlsbad, California | 108715014 | June 28, 2021 2
Comment 4: The Consultant should provide a statement regarding the impact of the proposed
grading and construction on adjacent properties and improvements.
Response: Provided that the planned improvements are constructed in accordance with the
recommendations provided in our geotechnical evaluation reports (Ninyo & Moore, 2017 and 2021),
as well as in accordance with the requirements of the applicable governing agencies, the planned
grading and construction is not anticipated to destabilize or have a negative impact to adjacent
properties and improvements.
Comment 5: The laboratory test data figures B-1 through B-4 were missing from the report. The Consultant should provide the missing figures.
Response: The referenced geotechnical report (Ninyo & Moore, 2017) included laboratory test
results on Figures B-1 through B-5 in Appendix B. For reference, Figures B-1 through B-4 are
attached to this letter.
Comment 6: Remedial grading recommendation in nonbuilding areas will leave existing fill in place. The consultant should demonstrate the suitability to support the proposed improvements and address.
Response: The remedial grading recommendations provided in the referenced geotechnical report
(Ninyo & Moore, 2017) are intended to provide uniform and consistent bearing conditions for the
planned building as well as nonbuilding improvements. The nonbuilding improvements (i.e., site
walls, pavements, etc.) will replace similar existing improvements. According to our review of the
project plans, we are of the opinion that the proposed nonbuilding improvements possess similar
load characteristics as those currently in place. Accordingly, we consider the lateral and vertical
extents of the remedial grading recommended in our geotechnical evaluation reports (Ninyo &
Moore, 2017 and 2021) to be suitable for support of the nonbuilding improvements.
Comment 7: Consultant should address minimum footing reinforcement recommendations from a geotechnical standpoint.
Response: We recommend that foundations be reinforced in accordance with the recommendations
of the project structural engineer. From a geotechnical standpoint, we recommend that continuous
footings be reinforced with four No. 4 reinforcing bars, two placed near the top of the footing and two
near the bottom.
Ninyo & Moore | 1906 Arenal Road, Carlsbad, California | 108715014 | June 28, 2021 3
We appreciate the opportunity to be of service.
Respectfully submitted,
NINYO & MOORE
Nissa M. Morton, PG, CEG Senior Project Geologist Jeffrey T. Kent, PE, GE Principal Engineer
NMM/JTK/gg
Attachments: References Figure 1 – Geotechnical Map
Figure 2 – Geologic Cross Section A-A’ Figure B-1 through B-4 – Laboratory Test Results (108438001)
Ninyo & Moore | 1906 Arenal Road, Carlsbad, California | 108715014 | June 28, 2021
REFERENCES
BWE, 2021, Grading Plans for Carlsbad Permanent Fire Station No. 2, 1906 Arenal Rd., Carlsbad, CA 92009, Drawing No. 530-8A, Sheets 1 through 7.
Hetherington Engineering, Inc., 2021, Third Party Review (First), Geotechnical Evaluation, Fire Station No. 2, 1906 Arenal Road, Carlsbad, California, Project ID: CUP2018-0014: dated May.
Ninyo & Moore, 2021, Update Addendum to Geotechnical Evaluation Report, Fire Station No. 2, 1906 Arenal Road, Carlsbad, California: dated January 14.
Ninyo & Moore, 2017, Geotechnical Evaluation, Fire Station No. 2, 1906 Arenal Road, Carlsbad, California: dated October 18.
AREN
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Geotechnical & Environmental Sciences Consultants
FIRE STATION NO. 2
1906 ARENAL ROAD, CARLSBAD, CALIFORNIA
108715014 I 6/21
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EXISTING TOPOGRAPHY
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PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 422
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NUMBERS HYDROMETER
GRADATION TEST RESULTS
FIRESTATION NO. 2
1906 ARENAL ROAD, CARLSBAD, CALIFORNIA
1084348001 | 10/17
FIGURE B-1
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PERFORMED IN GENERAL ACCORDANCE WITH ASTM D 3080
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Friction Angle
(degrees)Soil Type
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Depth
(ft)
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0
1000
2000
3000
4000
5000
0 1000 2000 3000 4000 5000SHEAR STRESS (PSF)NORMAL STRESS (PSF)
FIGURE B-2
DIRECT SHEAR TEST RESULTS
FIRESTATION NO. 2
1906 ARENAL ROAD, CARLSBAD, CALIFORNIA
1084348001 | 10/17
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UBC STANDARD 18-2 ASTM D 4829
EXPANSION INDEX TEST RESULTS
FIRESTATION NO. 2
1906 ARENAL ROAD, CARLSBAD, CALIFORNIA
1084348001 | 10/17
FIGURE B-3
108438001_EXPANSION - SDx3
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Geotechnlcal & Environmental Sciences Consultants
1 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 643
2 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 417
3 PERFORMED IN GENERAL ACCORDANCE WITH CALIFORNIA TEST METHOD 422
(ppm) (%)
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CHLORIDE
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(ppm)
pH 1SAMPLE
DEPTH (ft)
SAMPLE
LOCATION
RESISTIVITY 1
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SULFATE CONTENT 2
CORROSIVITY TEST RESULTS
FIRESTATION NO. 2
1906 ARENAL ROAD, CARLSBAD, CALIFORNIA
1084348001 | 10/17
FIGURE B-4
108438001_CORROSIVITY B-3 @ 1.5-4.0
Geotechnical & Environmental Sciences Consultants