8615 7TH AVE SE Geotech Report 2018-01-02 MF Import

St. Mary Magdalen Sport Covet Subsurface Exploration, Geologic Hazard, and Preliminary Geotecbnical Engineering Report aeration and drying prior to compaction in structural fill applications, weather dependent. Construction equipment traversing the site when the soils are wet can cause considerable disturbance. If fill is placed during wet weather or if proper compaction of the on -site soils cannot be obtained, a select, import material consisting of a clean, free -draining gravel and/or sand should be used. Free -draining fill consists of non -organic soil with the amount of fine-grained material limited to 5 percent by weight when measured on the minus No. 4 sieve fraction and 3t least 25 percent retained on the No. 4 sieve. 10.0 FOUNDATION RECOMMENDATIONS Spread footings may be used for building support when they are founded on approved structural fill placed as described above, or on the medium dense to dense till prepared as recommended in this report. If structural till is placed below footing areas, the structural fill should extend horizontally outward from the footing edges a distance equal to or greater than the thickness of the fill below the footing. Based on our understanding of the project, we anticipate that the majority of foundation elements will be founded upon the weathered to unweathered till soils. The footings for the proposed sport court may be designed for an allowable foundation soil hearing pressure of 3,000 pounds per square foot (psf), including both dead and live loads. An increase of one-third may be used for short-term wind or seismic loading. Perimeter footings should be buried at least 18 inches into the surrounding soil for frost protection. However, all foundation elements must penetrate to the prescribed bearing stratum, and no foundation elements should be constructed in or above loose, organic, or existing fill soils. Anticipated settlement of footings founded as recommended should be on the order of Y4 inch or less with differential settlement of 1/2 inch or less. However, disturbed material not removed from footing trenches prior to footing placement could result in increased settlements. All footing areas should be inspected by AESI prior to placing concrete to verify that the foundation subgrades are undisturbed and construction conforms to the recommendations contained in this report. Such inspections may be required by the City of Everett. Perimeter footing drains should be provided, as discussed under the section on Drainage Considerations. It should be noted that the area bounded by lines extending downward at 1HAV from any footing must not intersect another footing or intersect a filled area that has not been compacted to at least 95 percent of ASTM:D-1557. In addition, a 1.513:IV line extending down and away from any footing must not daylight because sloughing or raveling may eventually undermine April 24, 2006 Page 10 WIM - KEW-MAI - PmjraSl2W160KE1"