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Report Main Office &ranch Office P.O. Box 23814 4460 Hudson AVe., NE Inc. igard, Oregon 97281 Salem, OR 97301 Carlson. Testa Phone 1503) 684.3460 Phone (503) 689 - 1252 ? FAX (503) 684-0954 PAX (503) 689 -1309 December3, 1998 FILE Job No. 97 -G1388 S COPY I , FIELD INSPECTION REPORT Ala \O AfS — o - v 3e 7 PROJECT: Hawk Meadows Lots 10 ADDRESS: $W 114th Avenue = SW Gaar• a t. - Tigard, Oregon • INSPECTOR: r •larr D. Leach, E.I At the request of Alai DeHarpport, CTI engineering associate, Brian Leach, visited the above referenced lots at 3:00 PM on November 30, 1998. The purpose of his visit was to inspect subgrade soil conditions and drainage problems impacting the lots. The subgrade soils on kt 5 and 11 were observed and hand probed by CTI. The excavations have extended down approximately 3 feet through the preexisting uncompacted fill on the surface of the lots. The subgrade soils consisted of a medium stiff, brown and grey, clayey silt. The upper 6 inches of the subgrade has b$come water - softened due to the amount of rainfall in the past week. These softer soils should be "mucked" out immediately prior to pouring. The observed subgrade for Lots 5 and 11 are considered ¢uitable for a maximum allowable bearing pressure of 1,500 PSF. The subgrade soils on T 10 were also reviewed by CTI. From our observations, the excavation has extended down beyond the overlying, soft fill. During excavation, some moderate to large springs were encountered. Th 4 flow rate of the groundwaterwas estimated to be approximately 15 gal/min. CTI recommends constructing a gravel drainage blanket beneath the proposed foundation. The drainage blanket should consist of a minimum of 12 inches of clean crushed drain rock (2 " -3/4 ") capped with 12 inches 'of a clean crushed aggregate (3/4 " -0). The 3/4" -0 should be compacted to a minimum of 90% of the modified Proctor as determined by AASHTO T -180. CTI should conduct the density test to determine if the required compaction has been achieved. A perimeter footing drain is recommended for Lot 10. The drain should consist of a 6 -inch perforated or slotted pipe wrapped with fabric and covered with drain rock. This report is based solely on a visual inspection of the ground surface. No evaluation of subsurface conditions was performed. Information contained herein is not to be reproduced, except in full, without prior authorization from this office. If you have any questions regarding this report, please do not hesitate to contact Us. Respectfully submitted, GEOTECHNICAL DEPARTMENT CARLSON TESTING, IN =nan Leach, El. James D. Imbne. P.E. Engineering Associate Geotechnical Engineer cc: Riverwood Eeve .oprnen - _ -_— T — =. ' <e X573 ..v xy4t;h 3f'rm ,_ `mot' _ <w 'a u—