Loading...
Report --) Ceoracitic Engineering, Inc. Real -World Geotechnical Solutions Investigation • Design • Construction Support March 13, 2012 Project No 10 -2155 Mission Homes NW LLC PO BOX 1689 ti S l Z_d Qp n� Lake Oswego, OR 97035 r Phone 503 - 927 -1029 Fax 503 - 747 -5729 Email dalbey007@gmail.com FOUNDATION EXCAVATION REVIEW LOT 10 — HIGHLAND HILLS CITY OF TIGARD, OREGON GeoPacific Engineering Inc visited the site yesterday to review the single family home foundation layout on Lot 10. 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 site visit, soils exposed in foundation excavation consisted of predominantly moderately compact silt fill on the west half and medium stiff native silt on the east half that could be probed less than about 6 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 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. 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. 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 '/2 inch of loose soils are present prior to pouring concrete. 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. , PROF � �' GINF 2, 1 .1PE vA James D. Imbrie, G.E L % _ Geotechnical Engineer OREGON • 14835 SW 72 " Avenue /44I D W' Tel (503) 598 -8445 Portland, Oregon 97224 Fax (503) 941 -9281 EXPIRES: 06130/2.0 j