1304 80TH ST SW EVERETT SCHOOL DISTRICT 2018-01-02 MF Import

Subsurface Exploration and Everett Biu Facility Geoirrhniral Engineering Report Everett, Washingion Drsign Recommendations 3. Demolition and clearing beyond the improvement areas should be kept to a minimum. 4. Temporary silt fences should be provided along the lower margins of cleared/disturbed areas. 5. Temporary sediment catchment facilities should be cleaned out and maintained periodically, as necessary, to maintain their capacity and function. 6. Soils, which will be stockpiled at the site, should be stored in such a manner as to reduce erosion. Protective measures may include, but are not necessarily limited to, covering with plastic sheeting or the use of straw bales/silt fences. 7. 'temporary construction entrances should be constructed with quarry spalls or equivalent according to Snohomish County and City of Everett regulations. 7.0 STRUCTURAL. PILI. No major grade changes are anticipated at the site, and as such, the use of structural fill will be limited to minor grade changes for drainage, utility and vault backfill, and the removal of soft or yielding soils in parking lot areas. All references to structural fill in this report refer to subgrade preparation, fill type, placement, and compaction of materials as discussed in this section. In those areas where existing, uncontrolled, soft silty and/or organic fill is present, we recommend that it be removed, and where suitable, set aside for reuse in landscaping areas. Our recommendations for the placement of structural fill are presented in the following sections. 7.1 Fill Placement After stripping, planned excavation, and any required overexcavation have been performed to the satisfaction of the geotechnical engineer/engineering geologist, the upper 12 inches of exposed ground should be recompacted to at least 95 percent of the modified Proctor maximum density using ASTM:D-1557 as the standard. If the subgrade contains too much moisture, adequate recompaction may be difficult or impossible to obtain and should probably not be attempted. In lieu of recompaction, the area to receive fill should be blanketed with washed rock, quarry spalls, or crushed recycled concrete to act as a capillary break between the new fill and the wet subgrade. Structural fill should be placed and compacted within 2 percent of the optimum moisture content. After compaction of the exposed ground is tested and approved, or a free-draining rock course is laid, possibly in conjunction with engineering stabilization fabric, structural fill may be placed to attain desired grades. Structural fill is defined as non-organic soil, acceptable to the November 28, 2005 ASSOCIATED JiAR771 SCl1iA('ES, INC. EG11d.KEW,42n2-1'm1rrtrn12WJ6021WWP Page 7