REVIEWED RESUB BLD2021-0116+geo letter- shoring+2.15.2022_11.30.42_AM+2681622Irerracon
February 8, 2022
CA Senior Living Holdings, LLC
130 E. Randolph St., Ste 2100
Chicago, IL 60601
Attn: Mr. Michael Duggan — Vice President of Development
P: (312) 248-2091
E: mduggan@ca-ventures.com
Re: Shoring Plan Review (Rev. 5) - Permit No. BLD2021-0116
Anthology of Edmonds
21200 72nd Ave. W
Edmonds, Washington
Terracon Project No. 81185173
Dear Mr. Duggan:
This letter serves as documentation that Terracon has reviewed the Shoring Plans, Revision 5
dated December 28, 2021 prepared by Ground Support, PLLC. An initial review of the shoring
plans was completed by Terracon on Dec. 31, 2019. A second review was performed on August
27, 2021 for Revision 3 of the shoring plan. Both review letters are included as an attachment. It
was mentioned in both letters, and now in this letter, that the following comment should be
incorporated into the plan set from either review:
References to the geotechnical report addendums dated September 18 and December
6, 2019. (i.e. See SUBSURFACE DESIGN on SH1.0)
We anticipate that this will be our final request for review and that this comment will be
incorporated into the final version of the shoring plans.
Furthermore, the geotechnical engineering report and associated appendices recommend that
foundations bear on dense, native soils. Based on a linear interpolation between soil borings, the
projected contact of the dense, native layer suggests that footings between piles E4 and E9 could
require between 1/2 to 3 feet of overexcavation to satisfy the bearing capacity requirements. All
other footings along the shoring walls are projected to result in footing bases at or within the
dense, native contact. Terracon should be retained during construction to verify that dense, native
soils are observed at the assumed depth.
It appears the piles and tiebacks for E4 to E8 are sized the same as E9 and E10, which appear
to be designed for a wall height of about 14 feet. We recommend that the pile design for E4 to E8
be reviewed, and if necessary revised, to account for the possible need to overexcavate the
footings to the dense, native bearing stratum.
Terracon Consultants, Inc. 21905 64th Ave. W, Suite 100 Mountlake Terrace, WA 98043
P (425) 771 3304 F (425) 771 3549 www.terracon.com
Shoring Plan Review (Rev. 5) — Permit No. BLD2021-0116
Anthology of Edmonds Edmonds, Washington
February 8, 2022 Terracon Project No. 81185173
With the exceptions noted above, the design drawings and revisions appear consistent with the
recommendations provided in the geotechnical engineering report and associated addendum
letters.
We apprec
concerning
Sincerely,
Terracon
Zachary L.
Project Engineer
✓ice to you on &
------.-as(
Attachments:
Review Comments for City of Edmonds —Permit No. BLD19-1106 (Dec. 31, 2019)
Review Comments for City of Edmonds (Rev. 3) — Permit No. BLD2021-0116 (Aug. 27, 2021)
tions
Responsive ■ Resourceful ■ Reliable 2
Irerracon
December 31, 2019
CA Senior Living Holdings, LLC
130 E. Randolph St., Ste 2100
Chicago, IL 60601
Attn: Mr. Michael Duggan — Vice President of Development
P: (312) 248-2091
E: mduggan@ca-ventures.com
Re: Review Comments for City of Edmonds - Permit No. BLD19-1106
Edmonds Senior Living
21200 72nd Ave. W
Edmonds, Washington
Terracon Project No. 81185173
Dear Mr. Duggan:
This letter serves as our formal response to the City of Edmonds (the City) review comment
requesting review from the geotechnical engineer of the shoring design. The comment presented
from the City is as follows:
1) The geotechnical engineer for the project, Terracon, should review the shoring design for
compliance with the recommendations for shoring provided in the geotechnical report.
Terracon should provide a letter summarizing their review and providing any
recommendations. All recommendations need to be addressed in the resubmitted drawing
set. (Geotech Report, p. 16)
Terracon has completed a review of the stated design parameters presented in the design
memorandum prepared by Ground Support, PLLC (GS) and dated December 24, 2019. These
design parameters were used as input parameters in the design of the shoring system in what
appears to be design spreadsheets internally developed by GS. In general, the design is
consistent with the recommendations presented in the geotechnical engineering report though
GS has assumed several parameters that were not presented in the geotechnical engineering
report. We are comfortable with GS's assumed additional parameters. We request that the
following information be included/amended in the design memorandum:
References to the geotechnical report addendums dated September 18 and December
6, 2019.
Surface conditions summary references a fill and recessional outwash thickness of 15
feet whereas the geotechnical report references up to 13 feet.
Confirm a lateral earth pressure of 125 psf corresponds to the assumed vertical 250 psf
surcharge and 4 klf building load.
The Stage 1 cantilever condition for the north and east walls assumed a lateral pressure
of 75 psf while the full depth spreadsheet assumed 150 psf. The lateral earth pressure of
150 psf is presented on SH4.1. Confirm whether this discrepancy is intentional.
Terracon Consultants, Inc. 21905 64th Ave. W, Suite 100 Mountlake Terrace, WA 98043
P (425) 771 3304 F (425) 771 3549 www.terracon.com
Review Comments for City of Edmonds — Permit No. BLD19-1106
Edmonds Senior Living Edmonds, Washington
December 31, 2019 Terracon Project No. 81185173
The design drawings appear consistent with the recommendations provided in the geotechnical
engineering report.
We appreciate the opportunity to be of service to you on this project. If you have any questions
concerning this letter or if we may be of further service, please contact us.
Sincerely,
Terracon Consultants, Inc.
Zachary L. Koehn, P.E.
Project Engineer
David A. Baska, P.E.
Senior Engineering Consultant
Responsive ■ Resourceful ■ Reliable 2
Irerracon
August 27, 2021
CA Senior Living Holdings, LLC
130 E. Randolph St., Ste 2100
Chicago, IL 60601
Attn: Mr. Michael Duggan — Vice President of Development
P: (312) 248-2091
E: mduggan@ca-ventures.com
Re: Shoring Plan Review - Permit No. BLD2021-0116
Anthology of Edmonds
21200 72nd Ave. W
Edmonds, Washington
Terracon Project No. 81185173
Dear Mr. Duggan:
This letter serves as documentation that Terracon has reviewed the Shoring Plans, Revision 3
dated May 21, 2021 prepared by Ground Support, PLLC. An initial review of the shoring plans
was completed by Terracon on Dec. 31, 2019. That review letter is included as an attachment.
We noticed the following comments were not incorporated into the plan set from that review:
References to the geotechnical report addendums dated September 18 and December
6, 2019. (i.e. See SUBSURFACE DESIGN on SH1.0)
Based on our review, the design drawings and revisions appear consistent with the
recommendations provided in the geotechnical engineering report and associated addendum
letters.
We appreciate the opportunity to be of service to you on this project. If you have any questions
concerning this letter or if we may be of further service, please contact us.
Sincerely,
Terracon Consultants, Inc.
Zachary L. Koehn, P.E. David A. Baska, P.E.
Project Engineer Senior Engineering Consultant
Attachments:
Review Comments for City of Edmonds —Permit No. BLD19-1106 (Dec. 31, 2019)
Terracon Consultants, Inc. 21905 64th Ave. W, Suite 100 Mountlake Terrace, WA 98043
P (425) 771 3304 F (425) 771 3549 www.terracon.com