3611 FEDERAL AVE 2018-01-02 MF Import

Geologic Im,estigation and Geotechnical Engineering Report Jones Residence 3611 Federal: ve. Everen, Washington 98-08-10 Foundation settlement will be closely related to the quality of the site earthwork and the degree that the native soil has been disturbed during construction. For the alternatives given above, we estimate that total settlement of the foundation elements placed as recommended above wil not exceed '/4 of an inch, with differential settlements approximately '/2 of that total. It should be noted that actual settlements could increase if care is not exercised during site development and foundation construction. Slab on grade floor designs, especially within the garage areas, will be utilized on this site. We recommend that all floor slabs be placed with a minimum four-(4) inches of clean, free draining granular sand below them. If a vapor barrier is placed below the slab, we recommend that a minimum two-(2) inches of sand be placed between the slab and the barrier to allow for proper curing of the slab at the time of construction. 4.6 Earth Pressures Behind Walls All backtill placed behind walls or around foundation elements should be placed per the recommendations given above or within this section of the report. The following recommended earth pressures are presented as equivalent fluid pressures and are based on the assumptions of an uniform, level, granular backtill without buildup of hydrostatic pressures behind the wall. To minimize earth pressures and prevent the buildup of hydrostatic pressures, wall backfill should consist only of free draining granular material with drainage provisions as described below. If the backtilled walls are structurally restrained from lateral movement at the top, we recommend that the walls be designed for an equivalent weight of 60 pounds per cubic foot (pcf) to represent at rest pressures. If the tops of the walls are free to move laterally by an amount equal to at least 0. l percent of the wall height, they may be designed for active conditions using an equivalent fluid pressure of 38 pcf. Passive resistance is 400 pcf. Surcharges due to sloping ground, adjacent footings, vehicles, construction equipment, etc., must be added to these values. Only light hand- held vibratory equipment should be used to compact soil within 5 feet of all walls. For modeling under seismic conditions, we recommend that a dynamic rectangular pressure increment be added to the static equivalent fluid pressure in the form of 12H psf. 13 GES, Inc.