4020 COLBY AVE Geotech Report 2018-01-02 MF Import

McDonald's Corporation E-3676 December 21, 1987 Pa�e 5 Slab-on-Grade Floors Slab-on-grade floors may be supported on recomp�cted native soils or on structural fill. Any disturb2d native soils must either be recompacted or replaced with siructural fill. The siab should be provided with a minimum of four inches of free-draining sand or gravel. We also recommend that a vapor barrier such as a 6 mil plastic membrane be placed beneath the slab to reduce water vapor transmission through the slab and the resultant moisture accumula- tion. Two inches of sand may be placed over the membrane for protection during construction and to aid in curing of the concrete. Excavations and Slones in no case shonld excavation slopes be greater than the limits speci.fied in local, state and national goverr.ment safety regula- tions. Temporary cuts greater than four feet in height shou.ld have an inclination no steeper than 1:1 (Horizontal:Vertical) . We also recommend that all excavated slopes, if any, be examined by ECI to verify that conditions are as anticipated. Supplementary recommendations can then be developed, if needed, to improve stability, including flattening of slopes or installation of surface or subsurface drains. All permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficial layer of soil. Site Drainaae No groundwater was encountered in our borings. However, it has been our experience that groundwater levels change significantly due to changes in rainfall amounts, surface drainage or other far_tors. If seepage is encoutitered in the excavation, the water should be drained away from the site by use of drainage ditches, perforated pipes or French drains, or by pumping from sumps interconnectEd by shallow connector trenches at the bottom of the excavation. The excavation and site should be graded �o that surface water is directed off the site and away from the tops of slopes. Water should not be allowed to stand in any area where buildings, slabs, or pavements are to be constructed. During construction, loose surfaces shoul.d be sealed at night by compacting the surface soils to reduce the infiltration of rain into the soils. Final site grades srtould allow for drainage away from the building foundations. Earth Consultants, Inc.