Report AVOW 4
GeoP1c
Enginrrnng.flu:
Real-World Geotechnical Solutions
Investigation•Design•Construction Support
May 13, 2016
Project No. 12-2704
Stonebridge Project No. 1867
Stonebridge Homes 5 z �� " �'� 3
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503-387-7615
Email AndvC stonebridoehomesnw.com; JimD(A_stonebridgehomesnw.com;
kristentfdmhholdirgsco.com
RE: FOUNDATION SUBGRADE REVIEW
SOUTH VIEW SUBDIVISION LOT 3.
12078 TURNAGAIN DRIVE
TIGARD, OREGON
References: GeoPacific Engineering, Inc., Geotechnical Explorations, Knauss Property
Subdivision, 12035 Southwest Beef Bend Road, Washington County, Oregon, report
dated August 10, 2012
GeoPacific Engineering Inc. visited the site on last week to review the single family home foundation
subgrade on Lot 30. We understand that the proposed building is a two-story home, on downward
sloping lot. In our opinion, the observed subgrade is generally adequate for support to an allowable
bearing pressure of 1,500 psf. The expected maximum anticipated total and differential footing
movements (generally from soil expansion and/or settlement) are 1 inch and '/. inch, respectively,
over a span of 20 feet.
At the time of our site visit, the excavation was nearly complete. The front half of the excavation
consisted of predominantly stiff engineered fill soils that probed less than 1 to 3 inches with heavy
pressure using a steel "T" bar probe. The back half consisted of stiff native soils. Footing-to-slope
setbacks were adequate and foundation embedment depths appeared adequate. Some structural
backfilling will likely be required.
Due to silty soils encountered throughout the site, all foundations should incorporate appropriate
drainage measures. Crawlspaces should be provided with a low-point drain and pass through pipes
should be installed through footings which would otherwise restrict water flow to the low-point drain.
Care should be taken to avoid saturation or disturbance of footing subgrade soils during and after
excavation. If footing bearing soils become saturated or disturbed, any softened soil or slough
should be removed and replaced with crushed aggregate or additional concrete.
14835 SW 72nd Avenue Tel(503) 598-8445
Portland, Oregon 97224 Fax(503) 941-9281
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Project No. 12-2704
South View Lot 30
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.
Sincerely,
GEOPACIFIC ENGINEERING, INC.
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EXPIRES:0613012017
James D. Imbrie, P.E., G.E.
Geotechnical Engineer
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