Report D.c.18. 2013 3:33PM No. 4117 P.
Gee
Engineering, Inc.
Real -World Geotechnical Solutions
• Investigation
• Design
• Construction Support
December 18, 2013
Project No. 03 -8449
Stonebridge Homes Job No. 1451 / 5 -4t eg +� r
Attention: Andy Thomas and Jim Delmore ' T
Stonebridge Homes f / 2- t S- o024
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503- 387 -7615
Email JirnD c@stonebridclehomesnw.com
FOUNDATION SUBGRADE REVIEW
LOT 80— ARLINGTON HEIGHTS NO. 3
15468 SW SUMMERVIEW DRIVE
CITY OF TIGARD, OREGON
GeoPacific Engineering Inc. visited the site this week to review the single family home foundation
layout on Lot 80. The foundation excavation reached medium hard rock in several areas, some stiff
native soils, and some compact granular fill. 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. 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 72 inch of loose soils is present prior to
pouring concrete.
14835 SW 72 "d Avenue Tel (503) 598 -8445
Portland, Oregon 97224 Fax (503) 941 -9281
r
Dec. 18. 2013 3:33PM No. isj P.
GeoPacifiL E feetn Inc.
•
Job No. 03-8449
Lot 80 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: 06/30/20!5
James D. Imbrie, G.E.
Geotechnical Engineer