1318 37TH ST Geotech Report 2018-01-02 MF Import

. ( ; Jart=_s Pirie • JN 97072 • March 18, 1997 Page 4 The native soils have poor drainage characteristics so using them for wall backfill involves a risk that some water may seep through wa!Is. As a minimum, waterproofing should be provided where there will be below-grade, occupied spaces or moisture-sensitive areas, such as skorage and mechanical rooms. In general, the more care and expense taken dwing the initiai drainage and waterproofing in:�tallation, the fewer water problems that will develop later. Geotech Consultants, Inc. should be allowed to review the final development plans to verify that the recommendations presented in this report are adequately addressed in the design. Such a plan review would be additional work beyond the current scope of work for this study, and it may include revis;ons to our recommendations to accommodate site, development, and geotechnical constraints that become more evident during the revie�v process. Conventional Foundations The proposed structures can be supported on conventional cortinuous and spread footings bearing on undisturbed, med��m-dense to dense, native soii or on structural fill placed above this competent, native soil. See the later sub-section entitled General Earthwork and Structural Fill • for recommendations regarding the placement and compaction of structural fill beneath structures. VJe recommend that continuous and individual spread footings have minimum widths of 12 and 16 inches, respectEvely. They snould be bottomed at least 12 inches below the lowest adjacent finish � ground surface ior frost protection. The local building codes should be reviewed to determine if different footing widths or embedment depths are required. Footing subgrades must be cleaned of loose or dis:urbed soil prior to pouring concrete. Depending upon site and equipment constraints, this rnay require removing the disturbed soil by hand. Depending on the final site grades, some ovarexcavation may be required below the footings to expose competent, native soil. Uniess lean concrete is used to fill an overexcavated hole, the overexcavation must be at least as wide at the bottom as the sum of the depth of the overexcavaii,,n and the footing width. For example, an overexcavation extending 2 feet below tt�e bottom of a 3-foot-wide footing must be at least 5 feet wide at the base of ihe excavation. If lea� concrete is used, the overexcavation need onfy ?xtend 6 inches beyond the edges of the footing. The following allowable bearing pressures are appropriate for footings constructed acccrding to the above recommendations: Allowable Bearinq Condition Bearinq Pressuie Placed directly on competent, 4,000 psf � native soil Supported on structural fill placed 2,000 psf I � above competent, native soil I, Where: I psf is pounds per square foot. G[JTECH CONSULTANTS,INC. �ZO