9606 19TH AVE SE McDONALDS Geotech Report 2018-01-02 MF Import

GEOTECHNICAL ENGINEERING STUDY McDonald's Corporation June 9, 1995 E-6893-1 Page 6 Lateral loads may be resisted by friction between the foundations and the supporting native or compacted fill subgrade and by passive earth pressure on the buried portions of the foundations. The foundations must be poured "neat" against the ad;acent soil or the foundation excavation must be backfilled with structural fill. The following passive pressure and friction values include a factor of safety of 1.5: 0 Passive pressure = 350 pcf equivalent fluid weight • Coefficient of friction = 0.40 Footing excavations should be observed by a representative of ECI, prior to placing forms or rebar, to verify that exposed soil conditions are as anticipated in this report. Slab -on -Grade Floors Slab -on -grade floors may be supported on competent native soil or new structural fill. Should loose soil be present at the slab subgrade elevation, it should be compacted to the requirements of structural fill. Any disturbed subgrade soil must either be re - compacted or replaced with structural fill. Concrete slabs resting on soil ultimately cause the moisture content of the underlying soils to rise. This results from continued capillary rise and the ending of normal evapotranspiration. As concrete is permeable, moisture will eventually penetrate the slab unless some protection is provided. Therefore, the slab should be provided with a capillary break of a minimum of four inches of free -draining sand or gravel. In addition, in areas where slab moisture is undesirable, a vapor barrier such as a 6-mil plastic membrane should be placed beneath the slab. Two inches of damp sand should be placed over the membrane for protection during construction and to aid in curing of the concrete. Concrete toppings or additives and synthetic moisture -resistant memLranes may be used in lieu of a 6-mil plastic membrane in areas where moisture is undesirable. Information on the product usage, installation and warranty should be obtained from the manufacturer if these products are used. Enh Consultants. Inc.