1934 GRAND AVE 2016-01-01 MF Import

. ,_ ._-, Carl Pearson JN 95068 February 20, 1995 Page 5 access to �asing in case sloughing occurs in the near-surfac9 soils. 1f water is present in the hole at the time of pouring,the concrete should be tremied to the bottom of the hole. A wide varlety of dapths and pier diameters are possible, but we rer,ommend using a mini- mum pler diameter of 16 inches. For a minimum embedment of 10 feet into the denso sends and e pier dfameter of 16 inches, we recommend assuming an allowable compres- sive capacity of 15 tons per pier. All piers should be at least 20 feet in length, and center-to- center pier spacing should be no less than 3 times the pier diameter. Grade bearc�s shouid connect the piers together. We recommend designing the piers to cantilever for the upper 10 feet, wfth an equivalent fluid pressure of 60 pounds per cubic foot (pc� acting ov�r two times the pier diameter within the cantilever portion. For the purposes of reinforcement design, the soil adjacent to ihe d�llled pier below the cantllever portion can be assumed to have a passive earth pressure equal to that pressure exerted by a fluid with a density of 250 pcf acting on two times the pier diameter. The msximum bending moment can be assumed to occur at the bottom of the t(' -�ot candlever portion. We recommend reiniorcing the piers for their entire length. This typically consists of an upper ca�e of reinforcing steel, with a central steel bar extending the full length oi the pier. ptg�yo cansiderations We recommend the use of footing drains at the base of all footings and backfilled, earth- retsining walls. These drains should be surrounded by at least 6 inches of 1-inch-minus washed rodc wrapped In non-woven, geotextile filter fabric (Mirafi 140N, Supac 4NP, or similar meterlal). At(ts highest point, the perforated pipe invert should be at least as low as the bottom of the tooting, and it should be sloped for drafnage. All root and surtace water drafns must be kept separate from the toundation drain system. The excavation and site should be graded so that surface water is directed ott the site and awsy irom the top� of slopes. Water should not be allowed to stand in any area where foun- datlons, slsbs, or pavements are to be constructed. Final site grading in areas adjacent to the house should be s!oped at least 2 percent away from the building, except where the area fs paved. Water from roof, stormwater, and foundation drains should not be dis- charged onto the slope; it should be tightlined to a suitable outfall Iocated away from the slope. Grading should be conducted so that surtace water is not directed toward the slope. GL•O'I7SC11 CONtiUI:I'AN"IS,WC.