Report ?e- 5
GeoPacific
fn uicering.Inc
Real-World Geotechnical Solutions
Investigation • Design • Construction Support
March 12, 2015
Project No. 12-2704
Stonebridge Project No. 1845
Stonebridge Homes Y`
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503-387-7615
Email Andy(a7stonebridgehomesnw.corn; JimDt stonebridgehomesnw.corn
RE: FOUNDATION EXCAVATION REVIEW
SOUTH VIEW SUBDIVISION LOT 8- 15116 HARVEY'S VIEW AVENUE
TIGARD, OREGON
P4 c200 .? Li
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 yesterday to review the single family home foundation
subgrade on Lot 8. We understand that the proposed building is a two-story home extending over a
downward fill slope. 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 3/4 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 medium dense to dense, rocky fill soil that could be probed less than 2 inches with
heavy pressure using a steel "T" bar probe. These soils are considered adequate to support the
planned foundation loads. Footing-to-slope setbacks were adequate at more than 6 feet and
foundation embedment depths appeared adequate. Some interior backfilling may be necessary to
laterally support temporary vertical cuts.
Due to rocky and 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) 598-8445
Portland, Oregon 97224 Fax (503) 941-9281
Project No. 12-2704
South View Lot 8
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.
PROFFS,s
GINF9 X2
' 47 �i%
� �'// •
OREGON
✓,9 23.\
S D.t
EXPIRES:06/30/2OP
James D. Imbrie, P.E., G.E.
Geotechnical Engineer
•
-2-