6920 SEAWAY BLVD Geotech Report 2018-01-02 MF Import

1 1 impermeable vapor barrier should be placed betveen the slab and the free- draining sand and gravel. Tne need for a base course layer benea[h [he slabs 1 for o[her profect facilittes should be con:tdered on a case-by-case basis. Table 3 - Free-Draining Sand and Gravel � L'.S. Standard Sieve �o. Percen[ Passing by Weight I3-inch 90 - 100 No. 4 40 - 80 E Yo. 40 10 - 50 � No. 80 5 - 30 I No. 200 0 - 3 The settlement of on-grade sl.abs cons[ructed as recommended is expecCed I to be minor. LATERAL SOIL PRESSlJRES I The lateral soil pressures acting on basement walls and other re[�ining s[ructures will depend on the nature, density and configuration of [he soil Uehind the wall and [he amount oE ].ateral wall movement which can occur as IbackEill is placed. Por walls [ha[ are free to yield at the top at leas[ une- thousandth of the height of the wall, suil pr�ssures will be less than if � movement is limited by such Eactors as c+all stiffness or bracing. We recom- mend [hat yielding walls supporting horizen[al backfill be designed using an I equivalent fluid density of 35 pounds per cubic foot (pcf) , ahile nonyi.elding walls be designed using an equivalent Eluid densi[y of 55 pcf. The above- I recommended laceral soil pressures do not include [he effec[s of surcharges such as floor loads, [rafEic Loads or other surface Loading. Surcharge effects should be conside[ed, as app[opriate. All backfili for subgrade walls should be compacted co between 90 and 92 percent of the maximum dry density determined in accordance wi[h ASI'M D-1557. ?teasures should be [aken to prevent the buildup of excess la[eral soil pres- sures due to overcompaction oE the backEill hehind tl;e wall. Th3s can be accomplished by placing the zone of backEill located within 3 feet of [he wall in lifts not exceeding 8 inclies in loose thickness and compacting this zone with a hand-opera[ed or small selF-propelled vibrating plate compactor. I� - tt - �s@OEfIQInA@fS Incorporafed