1984-09-01 Soil Report - Laserfiche WebLink

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ANALYSIS AND RECOMMENDATIONS The existing fill and organic sells at this site are not suitable for support of a single family Cwelling. Some soil corr- ection work will be necessary to remove the unsuitable near su rf_ac soils and to densify loose or soft zones exposed during grading. The house will have a crawl space below the first floor in the living area. The garage floor will be designed as a slab -on -grade The existing fill, organic soils, and underlying soft alluvium should be removed from below footings, floor slabs, and associated oversizing areas. The thickness of unsuitable soils and corres- ponding elevation of the top of foundation subsoils suitable for footing support at our borings is esti:,,a*-d to be: TEST THICKNESS OF HOLE UNSUITABLE SOILS _`eet) ELEVATION OF TOP OF SUITABLE SUBSOILS ( feet) 1 5.5 927.7 2 10.0 921.6 As indicated above, the soft to stiff alluvial soils betwee the dep'-hs of 6.5 and 10 feet at Test Hole 2 are not suitable for footing support. However, these soils are suitable for support of the proposed garage slab. As a result, it will only be necessary to subcut to a depth of approximately 6.5 feet (Elev. 925.1 feet) below the garage slab in the vicinity of Test Holt 2. In the living area where no concrete slabs -on -grade are proposed, it will be necessary to excavate only for the footings, to the estimated elevations tabulated above. These footings can bear directly on the native, tough, clayey till. Due to the relatively high water table, it will be necessary to adequately dewater the footing excavations prior to casting footings. The footings should be excavated in small areas, and the concrete cast with a minimum of delay to avoid softening of the native clayey soils. It may be necessary to place an approximately 1 foot thick ness of washed gravel at the base of the ^xcavations to provide a wTiKing area, and to protect the clay from softening. SUBTERRANEAN ENGINEERING CORP. n MINNEAPOLIS, M.NNESOTA