Report Apr. 19. 2013 9:45AM No. 3729 P. 1
c1ic
Engineering, Inc.
Real -World Geotechnical Solutions
• Investigation
• Design
• Construction Support
April 19, 2013
Project No, 03 -8449
Stonebridge Homes Job No. 1469
Attention: Andy Thomas
Stonebridge Homes ``- S' "7 .3 nil C `75
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503 -387 -7615
FOUNDATION SUBGRADE REVIEW
LOT 98 - ARLINGTON HEIGHTS NO. 3
15439 SW SUMMERVIEW DRIVE
CITY OF TIGARD, OREGON 0.H -g0 /3 — G7 0o?,5
GeoPacific Engineering Inc. visited the site last week to review the single family home foundation
layout on Lot 98. 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 first site visit, the excavation was nearly complete and exposed medium stiff to stiff
native soil. These materials are considered adequate to support the planned foundation loads.
Footing to slope setbacks are adequate and footing -to -wall setbacks are not an issue.
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.
1483S SW 72" Avenue
Portland, Oregon 97224 Tel (503) S98 - 8445
Fax (503) 941!9281
Apr. 19. 2013 9:46AM GeoPaci 3729 : Inc.
Job No. 03 -8449
Lot 98 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: 06/30/20a
James D. Imbrie, G.E.
Geotechnical Engineer