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HomeMy WebLinkAboutPermit Field Test & Inspection Report 2002-4-9 -, . - ~ FO ~) ~\J:SS ~ _=ASS 3: \J ):~, INC. LAND SURVEYING. CONSTRUCTION SUPERVISION. WATER RIGHTS EXAMINATIONS CIVIL ENGINEERING . GEOTECHNICAL · ENVIR~0.;;l ~Ov~ April 9, 2002 Grassroots Development 1135 Cal Young Road Eugene, Oregon 97401 RE: Subgrade & Aggregate Compaction Evaluation Lot 66 - McKenzie Hills Subdivision Eugene, Oregon On April 8, 2002 a representative from Ford-Ness-Fassbender, Inc. hand-probed and evaluated the above referenced residential building lot to assess the subgrade for foundation bearing . capacity and shrink/swell potential of the soil. The follOWing observations and recommendations are provided for this lot to satisfy the City of Eugene's Option 2 Condition of Approval. ,~, , , . " . 'I Lot 66 - McKenzie Hills Subdivision : The builging pad portion ofthe lofwas cut to grade back In the late 1970's and has not been built upoh. ."" The surfaCe vegetation was removed from the eXisting grade and the west 5- to 1 0- feet of the lot was overexcavated approximately 12-inches. The silty clay subgrade was determined to be suitable for an allowable bearing capacity up to 1,500 pst. The subgrade soil has a low to moderated shrink/swell potential that is mitigated by the overlying aggregate. Site testing of the 8- to 10-inch thick layer of ~JJ_O crushed aggregate from Springfield Quarry indicates that the aggregated has been compacted to at least 95% of the materials maximum dry density of 133.5 pet as determined by AASHTO T-99 method. The subgrade and aggregate fill are suitable for conventional perimeter foundation construction. We recommend that footing be reinforced with at least two #4 steel reinforcing bars. The south Side of the lot has an approximately 8- to 10-foot high cut slope that was exposed during the initial pad excavation in the 1.979's and has been stable. This cut slope is approximately 1:4 (horizontal:vertical) and has been buttressed with 4- to 12-inch diameter rip- rap material placed at a 2:1 slope on the lower 4-feet of the cut bank. The exposed slope above the rip-rap is nearly nothing to the west and approximately 4 feet to the east. The area above the slope is generally covered with blackberry thickets and low brush. We recommend that surface drainage be directed away from the top of the slope and that adequate drainage be provided so that water does not accumulate at the toe of the slope. 116 Hwy. 99 N., SUite 1 00. P.O. Box 22 73 5. Eugene, OR 97402. (541) 344-1852 . Fax (541) 344-9923 E-mail: mall@fnflne net. Web site' www fnfine net CertIfied WB.E / D B E ~ ..... - . . McKenzie Hills - Lot 66 We recommend the landscape soil slope to direct surface water away from all foundations, and water should not pond adjacent to footings. Although not anticipated, should near surface seepage be present, a footing drain, consisting of 3-inch diameter perforated pipe encased in 1 cubic foot per foot of drain rock wrapped with filter fabric, or a suitable molded footing drain, be installed adjacent to all up slope footings. Sincerely, Ford-Ness-Fassbender Inc.