Report (2) GEDPfCIFIC
Real-World Geotechnical Solutions
Investigation • Design• Construction Support
August 31, 2022
Project No. 16-4108 /lri YStonebridge Job No. 31676 4
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Attention: Andy Thomas OO
Stonebridge Homes NW LLC
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503-387-7615
Email Andy(c�stonebridgehomesnw.corn; JimD(a�stonebridgehomesnw.corn;
kristen(a�dmhholdingsco.com
FOUNDATION SUBGRADE REVIEW
LOT 109 RIVER TERRACE CROSSING
15797 S.W. VANDERWOOD AVENUE
WASHINGTON COUNTY, OREGON
GeoPacific Engineering Inc. visited the site last week to review the single-family home foundation
subgrade at the above address. We understand that the proposed building is a two-story home. In
our opinion, the observed subgrade is adequate for support to an allowable bearing pressure of
1,500 psf.
At the time of our site visit, the excavation was complete and soils exposed in foundation excavation
consisted of predominantly stiff fill soils that could be probed about 2 to 6 inches with moderate
pressure using a steel "T" bar probe. The expected maximum anticipated total and differential
footing movements (generally from soil expansion and/or settlement) are 1 inch and 3/ inch,
respectively, over a span of 20 feet. The lot is gently sloped to the south side. Footing-to-wall and
footing-to-slope setbacks were not an issue.
Due to relatively impervious silty and clayey soils encountered throughout the site, all foundations
should incorporate appropriate drainage measures in accordance with the International Residential
Code. Adequate crawlspace drainage is not something that geotechnical consultants can verify; the
purpose of our visit is for observations of foundation bearing conditions only.
Our work scope pertains to a geotechnical engineer's foundation excavation review only and the
conditions existing and exposed at the time of our site visit. Within the limitations of scope, schedule
and budget, GeoPacific attempted to execute these services in accordance with generally accepted
professional principles and practices in the fields of geotechnical engineering and engineering
geology at the time the report was prepared. No warranty, express or implied, is made. If you have
any questions, please call.
14835 SW 72nd Avenue Tel (503) 598-8445
Portland,Oregon 97224 Fax(503)941-9281
A.
GEOPACIFIC
Job No. 16-4108
Lot 109 River Terrace Crossing
Sincerely,
GeoPacific Engineering, Inc.
,sozED PR OFFS
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EXPIRES:O6/30/2023
James D. Imbrie, G.E.
Geotechnical Engineer