1920 GRAND AVE 2016-01-01 MF Import

� D-1557 Modified Proctor method. We recommend that a representative from a qualified testing lab be on-site to monitor the placement of the fill and verify that the required compaction is achieved. Compaction tests should be pedormed at a frequency of one test per lik per 2,500 square fcet,or 500 lineal feet of trench. Due to the elevation of the water table, it may be difficult to place the structural fill at the base of the excavation. Stabilizing the base with crushed rock placed at the first lift of the stnutural fill may be necessary. Foundatlon Support Based upon the results of the subsurface exploration, it appears that after the cut is made for the basement,the foundation may be placed upon the dense sands and stiff silts which have adequate bearing capacity, However,due to the proximity of the stnuturo to the top of the slope those foundations within 15 feet of the top should be plsced upon drilled piers to support the foundation without loading the top of the slope. The remaining ponions of the stnuture may be placed upon a conventional spread footing. Footlngs The following criteria should be utilized in the design of the conventional spread footings: Maximum allowable bearing capacity: 3000 psf Friction against sliding: 03� Piles Drilled piers should be used for the support of all foundations within I S feet of the top of the slope. We anticipate that the piers may be drilled using open hole techniques,however, the contractor should have casing available to provide support of the pier excavation if needed. The piers should be a minimum of 16 inches in diameter, although larger diameters may be used. Cach pier should extend to a minirtmm depth of 20 feet below the finished basement elevation. If this criteria is used, the maximum allowable axial capaciry should be limited ro 15 tons per pier. Lateral capacity oF each pier will develop by an area over two times the diamerer of the pier, with a fluid equivalent pressure of 250 pcf and a point of fixiry located 10 feet below the surface. A one-third increase in allowable bearing capacity may be assumed in the design for short-term loads such as a seismic event or wind loading. We recommend that the soils engineer inspect all footing and pier excavations prior ro concrete placement to assure bearing capacity and that the conditions of the excavation are as anticipated. � Port Gardner Condominlums•GeotecMicel Repon Page 6