HomeMy WebLinkAboutCUP 2020-0003; RECYCLED WATER PHASE III D-4; GEOTECHNICAL REPORT UPDATE - RESPONSE TO COMMENTS FOR RECYCLED WATER PHASE 3 D-4 STORAGE RESERVOIR; 2023-01-12
15092 Avenue of Science, Suite 200 | San Diego, CA 92128 | www.NV5.com | Office 858.385.0500 | Fax 858.385.0400
MEMORANDUM
To: Neil Irani, Associate Engineer Date: January 12, 2023
From: Paul Cunningham, Senior Engineer Project: Carlsbad D-4 Reservoir
226816-0000111 CC: Carl Henderson, Julian Palacios NV5 Project
Number:
Subject: Geotechnical Report Update – Response to Comments list
Comments: See below for listing of page numbers within the updated geotechnical
report (updated 1/11/23) of answered comments (comments dated 11/4/22). If there
are any questions, please reach out by email to Paul Cunningham or Carl Henderson.
Addressed by new report
Addressed on page 14 of 79
Addressed on page 31 of 79
Addressed on page 32 of 79
Addressed on page 10 of 79
1. The submitted "Geotechnical Investigation Report ... " by NV5 is approximately 3.5-years
old and addresses an antiquated code cyde (2016 CBC and ASCE 7-10, etc.). Please
review the most current revisiion of the grading and other plans for the proposed project
and provide updated conclusions/recommendaHons to the report as necessary to address
the current codes and project.
2. Please provide a statement addressing the potential impact of the proposed project on
adjacent off-site properties from a geotechnical standpoint
3. Pl~ease provide an updated "Ge,otechnical Boring Map" (Figure 2) utilizing the most current
revision ofthe grading plan for the project as the base map and at a sufficfently large scare
to clearly show (at a minimum),: a) existing site topography, b) proposed waler tank and
any associiated improvements, c) proposed finished grades, d) geologic units, e) limits of
proposed remedial grading, and f) the locations of subsurface exploratron. Please note
that the "Geotechnical Boring Map" p.resented in the submitted report consists is relatively
4. Please provide the "Geologic Cross-Section· (Ffgure 3) based on the requested updated
"Geotechnical Boring Map" and scale/legibility comments requested above in comment
#3. Please assure the requested cross-section shows, at a minimum, a) existing site
topography and adjacent s.lopes, b) proposed finish grades, c) the limits of the proposed
water tank and associated improvements, d) the contacts between the so il/geologic units
underlying the site, e) limits and depths of proposed remedial grading, f) temporary slopes
necessary for the remedial grading for site retaining wall construction, and g) the locations
of subsurface exploration.
5. Please discuss the geologic structure of the Old Paral,ic Deposits as it relates to the
proposed project.
NV 5
Addressed on page 12 of 79
Addressed on page 22 of 79
Addressed on page 64 of 79
Addressed on page 19, 21 of 79
Addressed on page 20 of 79
Addressed on page 23 of 79
Addressed on page 25 of 79
Addressed on page 26 of 79
Regards,
Paul Cunningham, PE, GE
Senior Engineer
Paul.cunningham@nv5.com
6. Please provide a thorough discussion addressing the underlying geologic conditions and
stability of the approximate up to 40' high moderately descending slope that appears to
immediately bound the area of the proposed water tank and associated improvements
along the general ea.stem and southern portion of the site. Pease discuss both s,urficial
and gross slope stability of the desoending1 slopes wlth respect to the addition of the
proposed water tank and as they relate to the geotechnical pelfomiance of the proposed
water tank and associated improvements; provide justification (stability analysis) as
necessary to address site conditions.
7. Please provide updated seismic design parameters for the proposed development based
on the 2019 California Building Code and ASCE 7~16.
8. Please justify the use of Site Class C (in accordance with SecUon 1,613 of the 2019
California. Building Code and Chapter 20 of ASCE 7-16), to determine the seismic design
parameters provided in the report for tile Old Paralic Deposits.
9. Please clarify the approved embedment m,ate11ial (compacted fill, Old P·aralic Depoflits,
etc.) for new foundations (as the report refers to "natural soils-■
10. Please provide the minimum slab thickness and r,einfomlng for proposed -concrete slabs
associated wi1h the project from a geotechnicall standpoint.
11 .. Please1 p:rovi-de recommendations for asphart pavement design.
12. Pease provrde reoommendaUons for sulfate exposure for concrete design 1in accordance
With the 2019 California Building Code a.lld ACI 31 -8, Table,s 4.2.1 and 4.3.1.
· 3. Please pr,ovide a complete summery list of the geotechnical observationt/testing services
that should be performed as pan of the construciion of this proposed development.
NIVIS