the building pad fill in a manner that will not separate the overlap during <br />construction. Seams -that have separated will require removal of the <br />building pad fill to establish the required overlap. <br />14. Place a minimum of 24 inches of Granular Site Fill, Select Fill or <br />combinations thereof, to construct the building pads during wet <br />weather. If desired, the bottom of the pad may consist of Granular Site <br />Fill capped with a minimum of 6 inches of Select Fill. The feasibility of <br />using 6-inch minus, Granular Site Fill for most of the building pad should <br />consider the required depth of utility excavations through the pad. <br />Initial loads of rock should be placed by end-dumping adjacent to the <br />excavation and spreading the rock onto the fabric using a light dozer. <br />Subsequent loads may be spread from a thickened access ramp that <br />extends onto the fabric. The initial lift should be ± 18 inches thick and <br />compacted using a large vibratory roller. Do not allow continuous <br />construction traffic on the rock section until a minimum of 24 inches of <br />rock is placed. <br />Utility Construction <br />Utility contractors should be informed that water infiltration may be encountered at <br />shallow depths during the winter months. Where ground water is encountered, <br />trenches should be pumped dry prior to placing the backfill. Utility construction <br />within the west and central portions of the site is likely to encounter shallow <br />gravels. Significant seepage may occur in the gravels, depending on weather <br />conditions and river level. Seepage within the gravels typically causes sloughing <br />and caving of trench sidewalls. Deep trenching in the east portion of the site could <br />encounter sands and significant seepage. These conditions can also cause sudden <br />sidewall caving, thus requiring shoring and dewatering. <br />Trench backfill that extends beneath the new building, pavements and hardscapes <br />should consist of Select Fill placed and compacted as specified above. Shore all <br />excavations to protect workers from sloughing or caving soils according to Oregon <br />OSHA requirements for Type C soils. <br />Foundation Design and Construction <br />15. Design all continuous wall footings and isolated column footings using <br />an allowable bearing pressure of 2,500 psf. This value assumes that all <br />footings or Select Fill underlying the footings will extend to stiff alluvium <br />having a minimum undrained shear strength of 0.5 tsf. <br />16. Assume total settlement of the foundation for an individual building unit <br />of up to 1 inch. Differential movement within the building unit should <br />be A inch or less, if the footings are designed and built as specified <br />herein. <br />Oakleigh Meadows Cohousing February 12, 2013 <br />1 454 Geotechnical Investigation Project 2131004 <br />Eugene, Oregon 9. Willard C. Dixon Architect, LLC <br />