3105 PINE ST 2018-01-01 MF Import

Voth Brothers Construction, Inc. E-1201-1 October 20, 1980 Page 6 � For the above design criteria, it is anticipated that total „ settlements of footings in till will be about 3/4 inch� with dif- ; ferential settlements of half this amount. Almost all settle- ' ' ments should be realized during construction. ''j Footing excavations should be examined by a representative � of Earth Consultants, Inc. to verify that encountered conditions are as anticipated. Drains should be placed along all perimeter � footings and connected to a positive discharge system. Lateral Forces ^ Lateral forces may be resisted by backfill p�essures " against basement walls, passive pressures against the sides of foundations and by friction between the base of concrete foot- ' ings and the supporting subgrade. For calculating passive resis- � tance, an equivalent fluid weight of 400 pcf may be used in till and 300 pcf in the silty sand above the till, provided the foot- � � ings are poured neat or backfill is compacted to the require- ments for structural fill in the passive zone below the tops of � the footings. A value of 0.35 may be used for the friction coef- „ ficient at the base of footings. " Basement and Retaininq Walls " Basement and/or retaining walls should be designed to re- � + sist lateral earth pressures imposed by the soils retained by these structures. Walls that are free to rotate one-thousandth � � of their height at the top should be designed to resist lateral �., earth pressures imposed by an equivalent fluid with a unit weight of 35 pounds per cubic foot. If walls are restrained , . from free movement at the top, they should be designed for an additional uniform pressure of 120 pounds per square foot. ` The above pressures assume a maximum wall height of 10 feet ' and that no surcharge slopes or loads will occur above the walls. If deviations from these criteria are expected, we y should be contacted for the appropriate design parameters. All walls should be provided with adequate provisions for � subsurface drainage. Floor Slabs Slab-on-grade floors may be supported on the compacted sub- grade or on structural fill. In cut areas, the upper 12 inches of subgrade should be compacted to 95 percent of maximum density ` to provide uniform conditions beneath the slab. The slab should be provided with a minimum of 4 inches of free draining sand or ` gravel. In areas where moisture is undesirable, a vapor barrier Earth Consultants, Inc. � —