2802 HOYT AVE EVERETT ELKS Geotech Report 2018-01-02 MF Import

GeotechnicalEngineering Evaluation Everett Elks Club November 2, 2006 NGA File No. 751106 Page 7 the nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater copditions encountered. The following information is provided solely for the benefit of the owner and other design consultants and should not be construed to imply that Nelson Geotechnical Associptes, Inc. assumes responsibility for job site safety. Job site safety is the sole responsibility of the project contractor. For planning purposes, we recommend that temporary cuts in the sandier soils be no steeper than 1.5 Horizontal to I Vertical (1.5H:IV). If perched groundwater is encountered, we would expect that flatter inclinations would be necessary. We recommend that cut walls be protected from erosion. Measures taken may include covering cut walls with plastic sheeting and diverting surface runoff away from the top of cut slopes. We do not recommend vertical walls for cuts deeper than four feet, if worker access is necessary. Excavation spoils should be hauled off site and not be stockpiled near the cut walls. We recommend that cut slope heights and inclinations contort to appropriate OSHA/WISHA regulations. If the above -recommended inclinations are not feasible due to property boundary constraints, the planned cuts should be shored as recommended in the Shoring Wall subsection of this report. Site Preparation and Grading After the existing structure has been removed, the next step of site preparation should be to strip any undocumented fill, or loose material to expose medium dense or better native soils in foundation and slab areas. Approximately two feet of soil interpreted to be fill was encountered below the existing sidewalk in Boring 2 along Hoyt Avenue. The extent of the fill should be evaluated during construction. Excavations for the building foundations may need to be completed after any shoring systems are installed. If the ground surface, after excavating down to planned foundation subgrade elevations appears to be loose, it should be compacted to a non -yielding condition and then proof -rolled with a heavy rubber - tired piece of equipment. Areas observed to pump or weave during the proof -roll test should be reworked to structural fill specifications or over -excavated and replaced with properly compacted structural fill or rock spalls. If significant surface water now is encountered during excavation, this flow should be collected in small sump and pump pits and pumped out of the excavation. The exposed subgrade should not be compacted NELSON GEOTECHNICAL ASSOCIATES, INC.