Report (2) GaoP�c�ic
Real-World Geotechnical Solutions
Investigation-Design-Construction Support
January 25, 2016
Project No. 12-2704
Stonebridge Project No. 1851 ,^��,Z0 002.7
Stonebridge Homes
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503-387-7615
Email Andya@stonebddgehomesnw.com; JimDCa)-stonebridgehomesnw.com;
kristen -dmhholdingsco.com
RE: FOUNDATION SUBGRADE REVIEW
SOUTH VIEW SUBDIVISION LOT 14
12007 ALITLIMSLVIEW STREET
TIGARD, OREGON
References: GeoPacific Engineering, Inc., Geotechnical Explorations, Knauss Property
Subdivision, 12035 Southwest Beef Bend Road, Washington County, Oregon, report
dated August 10, 2012
GeoPacific Engineering Inc. visited the site on last week to review the single family home foundation
subgrade on Lot 14. We understand that the proposed building is a two-story home, garage under
home on an upward sloping lot. 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 site visit, the excavation was nearly complete. The excavation consisted of
predominantly stiff native soils that probed less than 1 to 4 inches with moderate pressure using a
steel "T" bar probe. These soils are considered adequate to support the planned foundation loads.
Footing-to-slope setbacks were adequate and foundation embedment depths appeared adequate.
Some structural backfilling will likely be required.
Due to silty 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. If footing bearing soils become saturated or disturbed, any softened soil or slough
should be removed and replaced with crushed aggregate or additional concrete.
14835 SW 72nd Avenue Tel(503)598-8448
Portland,Oregon 97224 Fax (503)941-9281
NEW-
r
Project No. 12-2704
South View Lot 14
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.
James D. imbrie, P.E., G.E.
Geotechnical Engineer
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