5016 HARBOR LN 2016-01-01 MF Import

� � � � � �. � � � i � � �A, .�. DAVIL� L. NELSON AND ASSOCIATES, INC. Consul[ing F.ngineering Geology October 27, 1988 Prnject No. 13288 Page 5 q the dense basal soils, composed of grey. dense. poorly sorted silty sand Nith 'I gravel (glacial ti11). As shown on the test pit logs, the depth belovi existing grade varies from about 2 to 10 feet below grade where explored, but�� could be someNhat deeper in the vicinity of the northeast corne of the structure. Foundations, consisting of conventional isolated or continuous spread footings, could expect net atla+aDle soil bearing pressures of 3000 pounds per square foot, placed directly within the dense native soils. A71 � footings should be placed a minimum of 18 inches be7av finish grade as to be belav frost 1eve1. AlternatiYely, the areas of deeper artificial fitl (lower I elevation dense basal soils) could be removed and replaced with structural fill (discussed below), and residence foundations placed upon the structural fill rather than the deeper native soils. Residence foundations placed within � � the adequate prepared and placed structural fill areas should anticipate net allowable soil bearing pressures of 2000 pounds per square foot. Removal of � the unsuitable soils above the dense basal soils, and replacement with structural fill, should be perfo►med so that the extent of fill occurs at II least 1.5 times the fi11 depth outside footing lines. We suggest the �� recortmendations as shown on the enclosed Subdrain d Backfill Schemes, sheet ' S-i and S-2, be used for footing placement, slab-on-grade placement, drainage and backfill performed ►vithin this site area. A minimum building setback of 25 feet from the located top-of-slope should be used for foundation placement. The setback, top-of-slope and slope area should not be disturbed, except for landscaping Nithin the setback area. Absolutely no filling should be perfornied within these areas, including "temporary" excavation materials from foundation preparation. All drainage should be directed away from these areas, and not allowed to freely flow over the setback, top-of-slope or slope areas. Any disturbed portions of these areas should be imnediately re-vegetated, using hydro-seeding, jute netting or vegetation planting. Foundations placed at the 25 feet setback line should be placed a minimum of 12 inches into the dense basal soils. If the setback is increased to 35 feet, the foundations could 1ie directly upon the dense basal soils.