HomeMy WebLinkAboutCT 16-07; MARJA ACRES; GEOTECHNICAL RESPONSE TO CITY OF CARLSBAD COMMENTS; 2021-12-17~ ~~~hnical, Inc.
To:
Attention:
Subject:
Reference:
December 17, 2021
NUWI Carlsbad, LLC
2001 Wilshire Boulevard, Suite 401
Santa Monica, California 90403
Mr. Jason Han, Partner
Project No. 21014-01
EnerGov Permit No. GR2021-0006
Project ID: CT160007
Development No. DEV 16038
Geotechnical Response to City of Carlsbad Comments, Rough Grade Plan Check
No. 4, Proposed Marja Acres Mixed Use Development, 4901 El Camino Real, City
of Carlsbad, County of San Diego, California
NMG Geotechnical, Inc., 2021, Supplemental Geotechnical Investigation and
Review of 40-Scale Grading Plan for Proposed Marja Acres Mixed Use
Development, 4901 El Camino Real, City of Carlsbad, County of San Diego,
California, Project No. 21014-01, dated July 26, 2021.
At the request if the project civil engineer HWL Planning & Engineering (HWL), NMG
Geotechnical, Inc. (NMG) has reviewed the City of Carlsbad rough grade plan check No. 4
geotechnical related comments and prepared this report in response to the plan checker's
comments. The comments were red-lined comments on a copy of the rough grade plan set
(Drawing 529-9A) for the subject project stamped received on November 8, 2021 by the Land
Development Engineering. NMG received the red-lined plans electronically on December 7, 2021.
Three were comments of a geotechnical nature where noted on three separate sheets (1 , 9 and 13).
SHEET 1
Soil Engineer's Certificate: Plan checker requests geotechnical stamp and signature.
NMG Response: The undersigned engineer will sign and stamp final grading plan title sheet.
17991 Fitch • In 111c. California 926 14 • Pl IONE (949) 442-2442 • FAX (949) 47(,-,322 • www.nmggct>lcchnical.com
SHEET 9
21014-01
December 17, 2021
Section 1-1 and Q-Q Red Line Comment: Provide letter from soil engineer that removal limits
are adequate to support wall.
NMG Response: The removals should be shown in similar fashion as on Section 2-2 on the same
sheet. The removal excavation should start in front of the walls at the property line or biological
buffer line as a 5-foot vertical cut which then transitions to a 1 H: 1 V sloped removal to the
recommended removal bottom (8 to 10 feet deep). Heavy benching should be performed into
the lH:lV excavation slope as compacted fill is brought up from the removal bottom in order to
provide essentially complete removals directly under the block portion of the MSE wall. The
engineered, compacted fills resulting from these removals will be adequate to support the walls.
Furthermore, settlement monitoring of these walls will be perfonned to verify anticipated
conditions.
Section K-K Red Line Comment: Comment provided by civil engineer (HWL) that plan checker
requested the soil engineer accept the dashed I: I zone of influence line projected from the toe of
wall footing adjacent to BMP zone.
NMG Response: The 1: 1 zone of influence line shown on the detail is geotechnically acceptable.
SHEET13
Section L-L Red Line Comment: Geotech has no problem with submerged wall? Provide letter.
NMG Response: The MSE wall is very small with only three feet exposed above ground and the
rest buried with biofiltration material in front of the wall. We also understand that a relatively
impermeable liner (30 mil HDPE) will be provided under the bioretention basin, further reducing
the impact of water in the basin next to the MSE wall. Furthermore, we expect only intennittent
water in the basin. Because of these factors, the potential submerged condition is geotechnically
acceptable.
2
21 1217 Response Report NMG
2l014-01
December 17, 2021
If you have any questions regarding this report, please contact our office. We appreciate the
opportunity to provide our services.
Respectfully submitted,
NMG GEOTECHNICAL, INC.
µ~
Ted Miyake, RCE 44864
Principal Engineer
TM/TW/je
Distribution: Addressee (E-Mail)
Mr. Jesse Kleist, KB Home (E-Mail)
~ ~~
Terri Wright, CEG)l342
Principal Geologist
Mr. Benny Sam, Madison Real Estate Consulting (E-mail)
Mr. Mel Landy, HWL (E-Mail)
3
211217 Response Repor1 NMG