1901 MERRILL CREEK PKY 2018-01-01 MF Import

� oversteepening. The stabiliry of slopes in the development area will be improved by proper handling of all surface and subsurface water. Specific drainage recommendations are discussed in following sections of this report. SHALLOW FOUNDATlONS We recommend that spread footings be founded on undisturbed competent native soils or a zone of structural fill placed above the dense glacial soils to achieve footing subgrade elevation. ! All column and continuous footings should have minimum widths of 3 feet and 18 inches, respectively. The footings should be founded at least 18 inches below the lowest adjacent grade to provide adequate confinement. ��' We recommend that spread footings founded on undismrbed glacial tiU be proportioned using a maximum allowable bearing value of 4,000 pounds per square foot (ps�. An allowable bearing value of 3,000 psf may be used for footings bearing on new structural fill placed to mat the compaction cciteria presented in the "Structural Pill" section of this reFArt. Where footings will be supported on stn�ctural fill, we recommend that the structural fill thiclmess extend to dense glacial seils. The allowable bearing values pruented above apply to the total of dead and long-term live � loads ezclusive of the weight of the footing and any overlying bac�ll. An increase in thae L� valua�f one-third may be used when considering wind or seismic loading. We recommend that � ali footing excavations be observed by a repraentative from our firm immediately prior to pouring the concrete for [he footings to conticm that the bearing surface has ban prepazed in a f� manner consistent with our recommendations. We estimate that postconstcuction settlements of footings suppocted on dense native soils will be less than 1/2 inch if founded as recommended above. Settlements of footings will be j slightly higher supported on postconstruction strucmral fill. Assuming a mazimum structural fill thickness of 4 feet, we estimate settlements could be up to 3/4 inch. Settlements of footings are expected to occur rapidly as loads are applied, due to the granular nature of the material. We estimate that the differential settlement between compazably loaded footings founded ' on similaz soil will be on the order of one-half the total settlement. Diffetential settlements ' between footings supporting different loads or between footings undetlain by different subgrade soils will be somewhat greater. SLAB-ON-GRADE SUPPORT Floor slabs should be founded on capillary break material as described below. We recommend that all silt, mud or other deleterious material that may have collected during construction be temoved by scraping the surface of the capillaq� break material prior to slab construction. The subgrade should possess a minimum density of at lesst 95 percent of the MDD (ASTM D-1557). My loose or disturbed areas should be overexcavated and bac�lled with stcuctural fill as dacribed previously. G e o E u � i n e e r t 10 FileNo. 1160.006-7]•1130/�11297