REVIEWED GeoTech ReportREVIEWED,.,.,.,.,..
BY
CITY OF EDMONDS
BUILDING DEPARTMENT;
April 8, 2022
ES-8520
Ms. Gretchen Pawling
755 Daley Street
Edmonds, Washington 98020
Subject: Geotechnical Consulting Services
Proposed Single -Family Residence
755 Daley Street
Edmonds, Washington
Reference: Scott M. Pawling, PE, MSCE (Pawling)
Geotechnical Report, dated May 17, 2013
Puget Sound Planning
Site Plan, dated November 29, 2021
Deccio Engineering
Civil Plans, dated November 22, 2021
Dear Ms. Pawling:
Earth Solutions NW LLC
Ceotechnical Engineering, Construction
Observation/Testing and Environmental Services
In accordance with your request, Earth Solutions NW, LLC (ESNW) has prepared this letter with
foundation support recommendations. The referenced geotechnical report prepared by Pawling
was reviewed as part of preparation of this letter.
Project Description
The proposed project will consist of construction of a new single-family residential structure and
associated improvements at the subject site. We anticipate the proposed residential structure
will be two to three stories in height and constructed utilizing relatively lightly loaded wood framing
supported on conventional continuous and spread footing foundations. We anticipate perimeter
footing loads of about 1 to 2 kips per linear foot. Slab -on -grade loading is anticipated to be
roughly 150 pounds per square foot (psf).
If the above design assumptions are incorrect or change, ESNW should be contacted to review
the recommendations provided in this report. ESNW should review final designs to confirm that
our geotechnical recommendations have been incorporated into project plans.
15365 N.E. 90th Street, Suite 100 0 Redmond, WA 98052 0 (425) 449-4704 0 FAX (425) 449-4711
Ms. Gretchen Pawling
April 8, 2022
Foundations
ES-8520
Page 2
The proposed residential structure can be constructed on conventional continuous and spread
footing foundations bearing on compacted native soil or new structural fill placed directly on
compacted native soil. ESNW should be retained during construction to perform a foundation
subgrade evaluation prior to formwork. Where loose or unsuitable conditions are encountered at
foundation subgrade elevations, compaction of the soils to the specifications of structural fill, or
overexcavation and replacement with structural fill will be necessary. Provided the structure is
supported as recommended above, the following parameters can be used for foundation design:
• Allowable soil bearing capacity 2,500 psf
• Passive earth pressure
• Coefficient of friction
300 pcf
1 E 1R
The passive earth pressure value provided above assumes the foundations will be backfilled with
structural fill. A factor -of -safety of 1.5 has been applied to the passive earth pressure and
coefficient of friction values provided in this section. For short-term wind and seismic loading, a
one-third increase in the allowable soil bearing capacity may be assumed.
With structural loading as expected, total settlement in the range of one inch is anticipated, with
differential settlement of about one-half inch. The majority of the settlements should occur during
construction, as dead loads are applied.
Seismic Design
The 2018 International Building Code recognizes the American Society of Civil Engineers (ASCE)
for seismic site class definitions. Based on the soil conditions encountered at hand auger boring
and test pit locations, in accordance with Table 20.3-1 of the ASCE Minimum Design Loads for
Buildings and Other Structures manual, Site Class D should be used for design.
Earth Solutions NW. LLC
Ms. Gretchen Pawling
April 8, 2022
We trust this letter meets your current needs
information is needed, please call.
Sincerely,
EARTH SOLUTIONS NW, LLC
.../2022
Henry T. Wright, P.E.
Associate Principal Engineer
ES-8520
Page 3
If you have any questions or if additional
cc: Leif Helleren Construction, Inc.
Attention: Mr. Leif Helleren (Email only)
Earth Solutions NW. LLC