1984-09-01 Soil Report - Laserfiche WebLink

Home Browse Search

Below the g,.rage slab -on -grade, it will be necessary to remo the mixed fill and organic soils and replace them witll compacted structural fill. The excavation should be oversized a minimum horizontal distance beyond the outer edge of perimeter footings 1 foot for each 1 foot of vertical cut, or 6 feet, whichever is greater. Temporary sideslopes of the excavation should not be steeper- than 1 horizontal: 1 vertical. The removed material is gen erally not suitable for re -use as structural fill and should be disposed of off site or in landscape areas. Non -organic portions of the existing fill can be selectively re -used as structural fill. A qualified Suil Engineer s►-ould work with the grading contractor to determine the suitability of re -using excavated materials and to determine the actual required excavation d.,pths in both footing ai,d slab areas, during grading. The excavation will likely extenu below the water table. For practical reasons, where it extends below the water table, the exposed base does not requ_re compaction. However, the excavation should be adequately dewatered and the base visible to so that obsLrvations and shallow hand auger prob-s can be made at t.►e botto Fill necessary to reach design grade should consist of ( s~.' sand or gravel with less than 10% passing the No.200 sieve, and free of foreign material or debris. It should be spread in loo lifts limited to 8 inches in thickness, and compacted to an average of 92% Maximum Modified Proctor Dry Density, A.S.T.M. D-1557 with individual values of at least 90�, Modified Proctor. If adequate d-watering is not possible, c':eck borings throug the completed fill above bases obscured by water and slurry will be necessary, to verify that all unsuitable soils have been removed. The proposed building may be supported upon conventional relatively shallow spread footing foundations founded on approved compacted fill or approved native subsoils. A ne' allowable soil bearing Pressure of 1500 pol.nds per square foot ahould be used for the footing design. SUBTERRANEAN ENGINEERING CORP. MINNEAPOLIS, MINNESOTA e