4800 DOGWOOD DR Geotech Report 2022-10-25

Subsurface Exploration, Geologic Hazards, View Ridge Community Church Addition and Geotechnical Engineering Report Everett, Washington Design Recommendations III. DESIGN RECOMMENDATIONS 8.0 INTRODUCTION The site is suitable for the proposed addition provided the recommendations presented in this report are properly implemented. Some portions of the site are underlain by a layer of surficial existing fill with a consistency that is very loose. The existing fill is not suitable for support of new foundations or structural backfill, and should be removed where they occur below areas planned for support of structural loads. Native sediments are suitable for support of lightly loaded shallow foundations and slab -on -grade, with proper preparation according to the recommendations presented in this report. 9.0 SITE PREPARATION Site preparation of the area for the new addition should include removal of all asphalt, sod, uncontrolled fill, organic debris, and any other deleterious material. Areas where looser native soils exist should be recompacted in place, or if this is not feasible due to either soil composition or moisture content, the loose soils should be removed and replaced as subsequently recommended for structural fill placement. In our opinion, stable construction slopes should be the responsibility of the contractor and should be determined during construction. For estimating purposes, we anticipate that temporary, unsupported cut slopes in the existing fill and advance outwash may be made at a maximum slope of 1.5H:1V (Horizontal:Vertical). As is typical with earthwork operations, some sloughing and raveling may occur, especially if ground water seepage is present in the excavation cuts, and cut slopes may have to be adjusted in the field. In addition, WISHA/OSHA regulations should be followed at all times. Permanent cut slopes in native sediments or structural fill must not exceed a 2H:1V inclination. Based on our observations, the on -site soils have a low to moderate percentage of fine-grained material making them slightly to moderately moisture -sensitive and subject to disturbance when wet. The contractor must use care during site preparation and excavation operations so that the underlying soils are not softened. If disturbance occurs, the softened soils should be removed and the area brought to grade with structural fill. Consideration should be given to protecting access and staging areas with an appropriate section of crushed rock or asphalt treated base (ATB). Any exposed soils should also be protected with plastic sheeting during the winter months. August 29, 2016 ASSOCIATED EARTH SCIENCES, INC. SKL11d - KE160351A2 - Projectsk20160351JKEJWP Page 10