Correspondence (8) May. 13. 2011 3:O6i'M No. 1756 P. 1
Coop ; ; • die
Engine'ering.Inc,
13910 SW Galbreath Drive
Sherwood, Oregon 97440
Tel (503) 625 -4455 • Fax (503) 6254405
May 12, 2011
Project No. 03 -8449
Attention: Blake Agate
Stonebridge Homes
4230 SW Galewood St., Ste. 100
Lake Oswego, OR 97035
Fax 503 - 387 -7615
FOUNDATION EXCAVATION REVIEW
LOT 67 --- ARLINGTON HEIGHTS NO. 3
CITY OF TIGARD, OREGON
GeoPacific Engineering Inc. visited the site today to review the single family home foundation layout
on Lot 67. We understand that the proposed budding 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 9 / inch, respectively, over a span of 20 feet.
The excavation was 2 to 5 feet deep to get through existing soft fill and some topsoil with roots. At
the time of our site visit, soils exposed in the bottom of the foundation excavation consisted of
predominantly very stiff loess, residual soil. These soils are considered adequate to support the
planned foundation loads. Footing -to -slope setbacks are not an issue and foundation embedment
depths appeared adequate.
Due to silty clay soils encountered throughout the site, all foundations should incorporate
appropriate drainage measures. Some minor trapped water was seeping from the rocky layers of fill_
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 1 /2 inch of loose soils is present prior to
pouring concrete.
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GeoPacifi Inc.
•
Job No. 03 -8449
Lot 67Arlington 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.
/ 14 E ,
OREGON
23 A ,
S D. tiM
EXPIRES: 06 /30/20 t i
James D. Imbrie, G.E.
Geotechnical Engineer
Michael K. Brown, S.E.
5346 E. Branchwood Dr.
Boise,, ID 83716
208 -850 -7542
Mikebrown.se@gmail.com
June 7, 2011 1
Dan Velasquez
. Stonebridge Homes ,
4230 SW Galewood St. Ste. 100
Lake Oswego, OR. 97035
Re: Lot 67, Arlington Heights
Tigard, Washington County, OR
Hold Down All Thread Length (Detail 5 & 6/S3)
Stonebridge Job Number: 1438
Engineer Job Number: DM11 -005
Dear Dan:
This letter is in regards to the All Thread Hold Down Anchor Bolt into the crawl space. Any
length of all thread may be used. The All Tread works in tension only and is not affected by
length. However, a wood post should be in line with the end of shear wall post above per detail
5 and 6/S3.
If you have ; questions, please do not hesitate to contact me.
Sincerely,
i
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Michael K. Brown