HomeMy WebLinkAboutSDP 2018-0004; ROMERIA POINTE APARTMENTS; GEOTECHNICAL UPDATE REPORT; 2021-08-17THESE PLANS/DOCUMENTS HAVE BEENREVIEWED FOR COMPLIANCE WITH THEAPPLICABLE CALIFORNIA BUILDING STANDARDSCODES AS ADOPTED BY THE STATE OFCALIFORNIA AND AMENDED BY THEJURISDICTION. PLAN REVIEW ACCEPTANCE OFDOCUMENTS DOES NOT AUTHORIZECONSTRUCTION TO PROCEED IN VIOLATION OFANY FEDERAL, STATE, NOR LOCAL REGULATION.BY: _________________ DATE: ________________
True North Compliance Services, Inc.
THIS SET OF THE PLANS AND SPECIFICATIONSMUST BE KEPT ON THE JOB SITE AT ALL TIMESAND IT IS UNLAWFUL TO MAKE ANY CHANGESOR ALTERATIONS WITHOUT PERMISSION FROMTHE CITY. OCCUPANCY OF STRUCTURE(S) ISNOT PERMITTED UNTIL FINAL APPROVAL ISGRANTED BY ALL APPLICABLE DEPARTMENTS.
Scott Weisse 07/23/24
GEOTECHNICAL UPDATE
ROMERIA POINTE APARTMENTS
7527 ROMERIA STREET
CARLSBAD SAN-DI ~ 009
ASSESSOR' , ND -13-00
Cl 04
•
BNR.JNVESTMl§bl'T AND DEVELOPM
-----28000 VIA DEi: RIO ----
YORBA LINDA, CALIFORNIA 92887
W.O. 7297-A4-SC AUGUST 17, 2021
•
Geotechnical • Geologic • Coastal • Environmental
5741 Palmer Way • Carlsbad, California 92010 • (760) 438-3155 • FAX (760) 931-0915 • www.geosoilsinc.com
August 17, 2021
BNR Investment and Development, LLC
28000 Via Del Rio
Yorba Linda, California 92887
Attention: Mr. Neal Desai
W.O. 7297-A4-SC
Subject: Geotechnical Update, Romeria Pointe Apartments, 7527 Romeria Street,
Carlsbad, San Diego County, California 92009, Assessor's Parcel Numbers
(APNs) 216-300-12-00 and -13-00, City of Carlsbad Project No.:
SDP2018-0004
Dear Mr. Desai:
In accordance with your request and authorization, GeoSoils, Inc. (GSI) is pleased to
present this geotechnical update relative to the planned multi-family residential
development at the subject site. The purpose of our study was to update the geotechnical
aspects of the planned development to the currently recognized building codes (i.e., the
2019 California Building Code [California Building Standards Commission, 2019] and the
American Society of Civil Engineers 7-16 [American Society of Civil Engineers, 2017] -see
the Appendix). The scope of our services has included reviews of the referenced
documents, listed in the Appendix, and the preparation of this summary report, which
provides updated geotechnical recommendations for seismic shaking parameters,
earthwork construction, and foundation design. Unless specifically superceded herein, the
conclusions and recommendations presented in the referenced geotechnical reports (see
the Appendix) remain valid and applicable, and should be appropriately implemented
during the balance of project design and construction.
UPDATED SEISMIC DESIGN PARAMETERS
The following table summarizes the updated site-specific seismic design criteria obtained
from the 2019 California Building Code (CBC), Chapter 16 Structural Design, Section 1613,
Earthquake Loads (California Building Standards Commission [CBSC], 2019) and
American Society of Civil Engineers (ASCE) 7-16 (ASCE, 2017). The computer program
Seismic Design Maps, provided by the California Office of Statewide Health Planning and
Development (OSHPD) and the Structural Engineers Association of California (SEAOC)
was utilized to calculate the mapped seismic design parameters (https://seismicmaps.org).
The short spectral response utilizes a period of 0.2 seconds. Based on a review of the
existing subsurface data summarized in the project geotechnical reports (see the
Appendix), it remains our conclusion that Site Class "D" conditions are applicable.
I 2019 CBC SEISMIC DESIGN PARAMETERS I
MAPPED VALUE PER SITE SPECIFIC
PARAMETER OSHPD/SEAOC VALUE PER 2019 CBC or REFERENCE
ASCE7-16
Risk Category(1l II II Table 1604.5
Site Class D D Section 1613.2.2/Chap. 20 ASCE
7-16 (p. 203-204)
Spectral Response -(0.2 sec), s. 0.968 g 0.840g Section 1613.2.1
Figure 1613.2.1 (1)
Spectral Response -(1 sec), S1 0.352 g 0.633 9 Section 1613.2.1
Figure 1613.2.1 (2)
Site Coefficient, F. 1.2 1.164(2) Table 1613.2.3(1)
Site Coefficient, Fv null -see Section 11 .48 2_5(3) Table 1613.2.3(2) ASCE 7-16 (Section 21 .3)
Maximum Considered Earthquake Spectral 1.161 g 1.263 9(4) Section 1613.2.3
Response Acceleration (0.2 sec), SMS (Section 21.4) (Eqn 16-36)
Maximum Considered Earthquake Spectral null -see Section 11 .48 1.026 9(5) Section 1613.2.3
Response Acceleration (1 sec),SM1 ASCE 7-16 (Section 21.4) (Eqn 16-37)
5% Damped Design Spectral Response 0.774g 0.8429(6) Section 1613.2.4
Acceleration (0.2 sec), Sos (Eqn 16-38)
5% Damped Design Spectral Response null -see Section 11 .48 0.6849(7) Section 1613.2.4
Acceleration (1 sec), S01 ASCE 7-16 (Section 21.4) (Eqn 16-39)
PG~ -Probabilistic Vertical Ground
Acceleration may be assumed as about 50% 0.507g 0.5289 ASCE 7-16 (Eqn 11 .8.1)
of these values.
Seismic Design Category null -see Section 11 .48 D(B) Section 1613.2.5/ASCE 7-16
ASCE 7-16 /Section 11.6) /o. 85: Table 11.6-1 or 11.6-2)
1. Risk Category to be confirmed by the Project Architect or Structural Engineer.
2. Per Table 11.4-1 of ASCE 7-16.
3. Per Section 21.3 of ASCE 7-16, if S1 ~ 0.2 then F v is taken as 2.5.
4. Per Section 21.4 of ASCE 7-16, SMS = (1.5)(Sos) = (1.5)(0.842 g) = 1.263 g.
5. Per Section 21.4 of ASCE 7-16, SM1 = (1 .5)(S01) = (1 .5)(0.684 g) = 1.026 g.
6. Per Section 21.4 of ASCE 7-16, Sos shall be taken as 90 percent of the maximum spectral acceleration (SJ obtained from the
site-specific spectrum at any period within the range from 0.2 to 5 seconds, inclusive.
7. Per Section 21.4 of ASCE 7-16, S01 shall be taken as the maximum value of the product TS. obtained from the site-specific spectrum
from the period within the range of 1 to 5 seconds, inclusive.
8. Per Table 11.6-1 of ASCE 7-16 Sn, ;, 0.2 = > 0.858 ;, 0.2. Thus the seismic desian cateaorv is "D".
UPDATED SEISMIC SURCHARGE FOR RETAINING WALL DESIGN
For building walls and site retaining walls with more than 6 feet of retained materials, as
measured vertically from the bottom of the wall footing at the heel to daylight, or retaining
walls that could present ingress/egress constraints to emergency equipment and
personnel in the event of failure, GSI recommends that the walls be evaluated for seismic
surcharge in general accordance with 2019 CBC requirements. The retaining walls in this
category should maintain an overturning Factor-of-Safety (FOS) of approximately 1.25
when the seismic surcharge (increment), is applied. For restrained walls, the seismic
surcharge should be applied as a uniform surcharge load from the bottom of the footing
(excluding shear keys) to the top of the backfill at the heel of the wall footing. For
cantilevered walls, the seismic increment should be applied as an inverted triangular
pressure distribution from 0.6H above the bottom of the wall footing to the top of the wall.
BNR Investment and Development, LLC
7527 Romeria Street, Carlsbad
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The seismic surcharge pressure (seismic increment) may be taken as 15H where "H" is the
wall dimensions for restrained and cantilevered retaining walls previously noted in the
preceding paragraph. For the evaluation of the seismic surcharge, the bearing pressure
may exceed the static value by one-third, considering the transient nature of this
surcharge. Please note this is for local wall stability only.
The seismic lateral earth pressure (increment) for the proposed retaining walls be obtained
from the following equation developed by the City of Los Angeles Department of Building
and Safety ([LADBS], 2020), which is based on Seed and Whitman (1970).
Where:
Y EFP(seismic)
Ysoi/
YEFP (seismic) = ¾khYsoil
is the seismic increment expressed as equivalent fluid pressure
(pounds per cubic foot [pcf]);
is the seismic lateral earth pressure coefficient equivalent to
one-half of two-thirds of PG~ (0.528 g x % x ½ = 0.176 g);
is the total unit weight of the retained soils (115 pcf)
Thus, for the proposed retaining walls:
Y EFP (seismic) = ¾ x ½ x % x 0.528 x 115 pcf = 15.2 pcf (use 15 pcf [15H])
UPDATED PRELIMINARY EARTHWORK CONSTRUCTION RECOMMENDATIONS
In addition to the preliminary recommendations contained in the referenced geotechnical
reports (see the Appendix), all earthwork should conform to the guidelines presented in
Appendix Chapter J of the 2019 California Building Code, and the requirements of the
City of Carlsbad. Grading should be performed under the observation and testing of GSI.
UPDATED PRELIMINARY RECOMMENDATIONS -FOUNDATIONS
The design and construction of the building foundations should conform to the preliminary
recommendations provided in the referenced geotechnical reports and the guidelines
presented in the 2019 California Building Code and American Society of Civil Engineers
7-16.
BNR Investment and Development, LLC
7527 Romeria Street, Carlsbad
File:e:\wp21 \7200\7297a4.gur GeoSoils, Inc.
W.O. 7297-A4-SC
August 17, 2021
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LIMITATIONS
The materials encountered on the project site and utilized for our analysis are believed
representative of the area; however, soil and bedrock materials vary in character between
excavations and natural outcrops or conditions exposed during mass grading. Site
conditions may vary due to seasonal changes or other factors.
Inasmuch as our study is based upon our review and engineering analyses and laboratory
data, the conclusions and recommendations are professional opinions. These opinions
have been derived in accordance with current standards of practice, and no warranty,
either express or implied, is given. Standards of practice are subject to change with time.
GSI assumes no responsibility or liability for work or testing performed by others, or their
inaction; or work performed when GSI is not requested to be onsite, to evaluate if our
recommendations have been properly implemented. Use of this report constitutes an
agreement and consent by the user to all the limitations outlined above, notwithstanding
any other agreements that may be in place. In addition, this report may be subject to
review by the controlling authorities. Thus, this report brings to completion our scope of
services for this portion of the project.
BNR Investment and Development, LLC
7527 Romeria Street, Carlsbad
File:e:\wp21 \7200\7297a4.gur GeoSoils, Inc.
W.O. 7297-A4-SC
August 17, 2021
Page4
The opportunity to be of service is sincerely appreciated. If you should have any
questions, please do not hesitate to contact our office.
Respectfully submitted,
GeoSoils, Inc.
~~-1:::!-
Engineering Geologist,
!B1!e, -
Staff Geologist
RBB/JPF /DWS/sh
Attachments:
Distribution:
Appendix -References
(1) Addressee (via email)
~~
Civil Engineer, ACE 47857
(1) Streamline Development Group
BNR Investment and Development, LLC
7527 Romeria Street, Carlsbad
File:e:\wp21 \7200\7297a4.gur GeoSoils, Inc.
W.O. 7297-A4-SC
August 17, 2021
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APPENDIX
REFERENCES
American Society of Civil Engineers, 2017, minimum design loads and associated criteria
for buildings and other structures, provisions, ASCE Standard ASCE/SEI 7-16.
California Building Standards Commission, 2019, California Building Code, California Code
of Regulations, Title 24, Part 2, Volumes 1 and 2, based on the 2018 International
Building Code.
City of Los Angeles Department of Building and Safety, 2020, Information bulletin/ public -
building code, reference no.: LABC 1610.1, 1807.2, document no.: P/BC 2020-083,
dated January 1 .
GeoSoils, Inc., 2019, Geotechnical response to issues raised at the June 11, 2019 City of
Carlsbad City Council meeting pertaining to the geotechnical conditions at the
Romeria Pointe Apartments project site and near vicinity, 7527 Romeria Street,
Carlsbad, San Diego County, California 92009, Assessor's Parcel Numbers (APNs)
216-300-12 &-13, City of Carlsbad project no.: SDP2018-0004, W.O. 7297-A3-SC,
dated November 30.
__ , 2018a, Geotechnical response to City of Carlsbad review comments dated October
19, 2018, Romeria Pointe Apartments, 7527 Romeria Street, Carlsbad, San Diego
County, California 92009, Assessor's Parcel Numbers (APNs) 216-300-12 &-13, City
of Carlsbad Project No.: SDP2018-0004, W.O. 7297-A2-SC, dated December 6.
__ , 2018b, Geotechnical review of title sheet and preliminary grading plans for: Romeria
Pointe, 7527 Romeria Street, Carlsbad, San Diego County, California 92009,
Assessor's Parcel Numbers (APNs) 216-300-12 & -13, W.O. 7297-A1-SC, dated
September 12.
__ , 2017, Geotechnical update evaluation, Romeria Pointe, multi-family residential
development, Assessor's Parcel Numbers (APNs) 216-300-12 & -13, Carlsbad,
San Diego County, California, W.O. 7297-A-SC, dated November 21.
__ , 2007a, Final geotechnical review offoundation (drilled pier and post-tensioned slab)
plans, notes, and details, Romeria Pointe Townhomes, Carlsbad, San Diego
County, California, W.O. 4460-A6-SC, dated November 14.
__ , 2007b, Geotechnical review of structural plans, Romeria Pointe Townhomes,
Carlsbad, San Diego County, California, W.O. 4460-A4-SC, dated February 22.
__ , 2006a, Memorandum: General discussion of recent cone penetration tests,
Building A, Romeria Point, Carlsbad, California, W.O. 4460-A3-SC, dated
October 13.
GeoSoils, Inc.
__ , 2006b, Revised geotechnical review of grading, post-tension foundation, and
structural plans, Romeria Pointe Townhomes, Carlsbad, San Diego County,
California, W.O. 4460-A3-SC, dated July 26.
__ , 2006c, Geotechnical review of grading, post-tension foundation, and structural
plans, Romeria Pointe Townhomes, Carlsbad, San Diego County, California,
W.O. 4460-A3-SC, dated July 21.
__ , 2005, Geotechnical review of post-tension foundation and structural plans, Romeria
Pointe Town homes, Carlsbad, San Diego County, California, W.O. 4460-A 1-SC,
dated March 8.
__ , 2004, Preliminary geotechnical evaluation, Romeria Pointe, APNs 216-300-12
and -13, Carlsbad, San Diego County, California, W.O. 4460-A-SC, dated
September 27.
Seed, H. B. and Whitman, R. V., 1970, Design of earth retaining structures for dynamic
loads, ASCE Specialty Conference, Lateral Stresses in the Ground and Design of
Earth Retaining Structures, pp. 103-147.
BNR Investment and Development, LLC .
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Appendix
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