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Report /ag GeoP o 6igmeernlg.lne Real-World Geotechnical Solutions Investigation•Design•Construction Support May 13, 2016 Project No. 12-2704 Stonebridge Project No. 1868 Stonebridge Homes 5T2dg - 00)53 4230 SW Galewood St., Ste. 100 Lake Oswego, OR 97035 Fax 503-387-7615 Email Andytstonebridgehomesnw.com; JimDcstonebridoehomesnw.com; kristenQdmhhokiingsco.com RE: FOUNDATION SUBGRADE REVIEW SOUTH VIEW SUBDIVISION LOT 31 12066 TURNAGAIN DRIVE 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 31. We understand that the proposed building is a two-story home, on downward 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 34 inch, respectively, over a span of 20 feet. At the time of our site visit, the excavation was nearly complete. The front half of the excavation consisted of predominantly stiff engineered fill soils that probed less than 1 to 3 inches with heavy pressure using a steel "T" bar probe. The back half consisted of stiff native soils. 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, should be removed and replaced with crushed aggregate or aitiional anysoftenessoil or slough 14835 SW 72nd Avenue Tel (503)598-8445 Portland, Oregon 97224 Fax(503) 941-9281 Project No. 12-2704 South-View Lot 31 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. RQPFikFs, „,5 S/0 le 0`EGvN q 23 � � �S D.IMF'' EXPIRES:06/30/20/2 James D. Imbrie, P.E., G.E. Geotechnical Engineer -2-