Report Mar. 9. 2012 3: 01 PM No. 2748 P. 1
GOPIiIC
Engineering, Inc.
14835 SW 72n Avenue
Portland, Oregon 97224
Tel (503) 598 -8445 • Fax (503) 941-9281
March 9, 2012
Project No. 03 -8449
Stonebridge Homes Job No. 1436
Attention: Andy Thomas
Stonebridge Homes
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503 -387 -7615 and 503 -746 -6214
FO_ON lATION EXCAVATION REVIEW
1OT4 DARLINGTON HEIGHTS NO.3 A l / 5 1 - 0 2 0 ( f - coo 9 7
15238 SW SUMMERVIEW DRIVE
CITY OF TIGARD, OREGON
GeoPacific Engineering Inc. visited the site today to review the single family home foundation layout
on Lot 65. "We understand that the proposed building is a two -story home. 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 upper portion of the excavation was benched 1.5 to 2 feet into
the existing 25 percent side slope on the fill lot. It was excavated 1.5 to 2 feet to get below poorly
compacted fill. Once the excavator deepened the excavation he encountered suitably stiff fill soils.
These soils are considered adequate to support the planned foundation loads.
Due to silty clay 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. 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 Y2 inch of loose soils is present prior to
pouring concrete.
Mar, 9. 2012 3 : O 1 PM GeoPacific cn�g Inc.
• Job No. 03-8449
Lot 65 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: 06/30120j,3
James D. lmbrie, G.E.
Geotechnical Engineer
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