Report 44cr , eX700
GeoP F cifI
Engineering,Inc,
Real-World Geotechnical Solutions
Investigation• Design•Construction Support
Revised August 18, 2014
Project No. 13-3103
Kurt Dalbey
Spectrum Development
PO Box 1689
Lake Oswego, Oregon 97035
FOUNDATION EXCAVATION REVIEW
LUKAR RIDGE LOT 1
TIGARD, OREGON
Reference:Geotechnical Report,Lukar Ridge Subdivision, 14235 SW Fern Street,Tigard,Oregon,September 6,2013.
GeoPacific Engineering Inc. visited the site last week to review the single family home foundation subgrade on
Lot 1. 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 static and 2,000 psf pseudostatic.
The expected maximum anticipated total and differential footing movements (generally from soil expansion
and/or settlement) are 1 inch and 'A inch, respectively, over a span of 20 feet.
At the time of our site visit, soils exposed in foundation excavation consisted of stiff native soils and very stiff to
hard compacted fill that could be probed less than about 1 to 2 inches with medium pressure using a steel "T"
bar probe. These soils are considered adequate to support the planned foundation loads. Footing-to-slope
setbacks were not an issue. The contractor will backfill in front of and behind the garage retaining wall with
compacted gravel after the foundation is poured; this is acceptable provided there is at least 4 feet horizontal
of level grade in front of the buried portion of the wall. The assumed design parameters reviewed in Sheet
S2.2 of Horn Consulting Engineers LLC are appropriate for the soil types at the site, the proposed backfilling,
and for overall design of the garage wall.
Due to relatively impervious clayey silt 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.
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, ` =,- If you have any questions, please call.
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Sincerely, �5 GINF %p
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GeoPacific Engineering, Inc. /
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James D. Imbrie, G.E. `"4,1 SSD.11■10 Q'
Geotechnical Engineer
rw 'nrt,oF4o/2013
14835 SW 72nd Avenue Tel(503)598-8445
Portland,Oregon 97224 Fax(503)941-9281