Report r i��lJ
GeoPIIN
Engineering,Inc,
Real-World Geotechnical Solutions
•Investigation
•Design
•Construction Support
August 29, 2013
Project No. 03-8449
Stonebridge Homes Job No. 1427 /Sl7fo Sv
7\92v 7-cwt'
Attention:Andy Thomas o
Stonebridge Homes
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503-387-7615
FOUNDATION SUBGRADE REVIEW
LOT 56—ARLINGTON HEIGHTS NO.3
15176 SW SUMMERVIEW DRIVE
CITY OF TIGARD,OREGON
GeoPacific Engineering Inc. visited the site August 20th and 28th to review the single family home
foundation layout on Lot 56. Some soft and organic fill was encountered in the rear footing line of the
home. This material was removed by deepening to reach native soils. Engineered fill was observed of
the majority of the home. 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 '/a
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 stiff native soils on the rear footing line. 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
crawispace 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 72id Avenue Tel(503)598-8445
Portland,Oregon 97224 Fax(503)941-9281
GeoPacific"Liiaiiieel.,.y, Inc.
Job No.03-8449
Lot 56 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.
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EXPIRES:06130!2015
James D. Imbrie, G.E.
Geotechnical Engineer