09-22-2004 Council Agenda - Laserfiche WebLink

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Rug 26 04 07:56a Jon Whitcomb AUG 25 '04 02 :39PM BRAUN INTERTEC 0.3. Foundation/Basement Walls 651- 430 -0029 Wesley Investments, Inc. Project: SP -04 -03734 May 21, 2004 Page 7 p. 12 P. 12/23 D.3.a. Lateral Earth Pressure. We recommend that hackfrii placed on the exterior sides of the foundation/basement walls be compacted to a minimum of 90 percent of the standard Proctor maximum dry density. Beneath steps, slabs and pavements, it should be compacted to a minimum of 95 percent. For the on -site clayey soils, we recommend using a lateral earth pressure of 65 psfper foot of depth (pcf) for wall design, This value assumes at -rest earth pressure conditions.. D.3.b. Seepage Control. We recommend that the site be graded with positive drainage away from foundations. We recommend installing a perimeter foundation drain system. The system should include a perforated pipe with an invert within 2 inches of bottom -of- footing elevation. Collected seepage should be routed to a sump and then drained by a pump or gravity to a storm sewer or outlet to a low area. The seepage control system should include permeable material against the basement wall, such as a synthetic wall drainage system or at least 2 feet (hori2ontat).of permeable sandy gravel or sand backfill. The sandy gravel or sand backfli should have lass than 5 percent of the particles by weight passing a 200 sieve. Where the sandy gravel or sand back-fill extends outside the footprint of the building, it should be capped by a slab, pavement or at least 1 foot of topsoil and clay. D.4. Floor Stabs We recoinmend that floor slab elevations be designed to provide ar least a 4 -foot separation between the slabs and static uoundwater and at least 2 feet above The 100-year flood elevation of nearby ponds, wetlands or lakes. We recommend that you check with city personnel for their requirements for establishing lowest floor elevations. :f floor coverings or coatings less permeable than the concrete slab will be used, we recommend that a vapor barrier /retarder be placed beneath the slab. Some contractors prefer to bury the vapor barrier beneath a Layer of sand to reduce curling of tha floor slabs.