Report - ` May. 16. 2013 12:55PM : No. 3809 P. 1
GOOP
Real -World Geotechnical Solutions
• Investigation
• Design
• Construction Support
May 16, 2013
Project No. 03 -8449
Stonebridge Homes Job No. 1490
Attention: Andy Thomas
Stonebridge Homes
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503 - 387 -7615
FOUNDATION SUBGRADE REVIEW
LOT 119 — ARLINGTON HEIGHTS NO.3 r 000
12641 SW CANYONRIDGE COURT
CITY OF TIGARD, OREGON
GeoPacific Engineering Inc. visited the site May 10 and 15th to review the single family home
foundation layout on Lot 119. Some soft and organic fill was encountered in the rear footing line of
the home. This material was overexcavated and replaced with compacted granular fill. In our opinion,
the observed subgrade is now 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 3 inch, respectively, over a span of 20 feet.
At the time of our final site visit, the excavation was complete and exposed medium stiff to stiff fill
soils on the front and very compact granular reject rock on the rear footing line. Compaction tests
achieved 95 % of the standard Proctor. These materials are considered adequate to support the
planned foundation loads. Footing to slope setbacks are adequate and footing -to -wall setbacks are
also adequate.
Due to relatively impervious 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.
Care should be taken to avoid saturation or disturbance of footing subgrade soils during and after
excavation. We observed some placement of crushed aggregate to protect the subgrade from wet
weather. If footing bearing soils become saturated or disturbed, any softened soil or slough should
be removed and replaced with crushed aggregate or additional concrete. In general, footing
excavations should be cleaned such that no more than about 1 /2 inch of loose soils is present prior to
pouring concrete.
14835 SW 72 Avenue Tel (503) 593-8445
Portland, Oregon 97224 Fax (503) 941-9231
May. 16. 2013 12:55PM GeoPacifi Inc.
Job No. 03 -8449
Lot 119 Arlington Heights No. 3
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.
PROFFc,
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OREGON
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EXPIRES: O6/30/20a
James D. Imbrie, G.E.
Geotechnical Engineer