2908 49TH ST SW 2016-01-01 MF Import

September 7, 2010 Mr. John Mustach L&A Job No. 10-036 Pagc 6 below the adjaccnt finish grade in front of the block wall. The precast concrete blocks should be stacked tighdy against one another. Drainagc Control A minimum G-inch perforated, rigid, PVC drain line fitted in a non-woven filter fabric sock should be laid in the kcyway trench behind thc base-course blocks. The bottom of keyway trench and the drain line should have su�cient slope (0.5 percent minimum) to generate flow hy gravity. The drain pipe should be iighUined to dischazge into a splash pad constructed with 4 to 6 inch rock spalls placcd uvcr the ditch off the southwest wmer of the site to dissipate energy of discharged watec A minimum 10-inch-thick (horizontally) vertical drainage blanket, constructed of clean I-inch washed gravcl or 7/8-inch crushed rock, should bc; placed against the back of thc block wall. 1'his vertical drainage blanket should be hydraulically connected to the drain line at tlte base behind the wall. 1'hc wall backftll bchind the vertical drainage blanket should consist of structural fill. 'I'he vcrlical drainage blanket and structural fill should be constructed in lifls after cach course of blocks is complctcd. Wall Back611 Wall backfill behind thc vertical drainagc blanket should consist of compacted structural fill. Structural fill should bc composcd of clean, granular soils frce of organics and debris, with partides no larger than threc inches. Onsite clean Esperance Sand soil meeting the above rcyuiremcnts may bc uscd as structural filL SWctural ftll should havc a moisturc contcnt within onc percent ot' its optimum moisture content at the time of placement. The optimum moisture content is the waler content in the soil that enables the soil to be compacted to the highest dry densiry for a given compaction etTort. Imporled material to be used as structural fill, should bc clean, fiec-draining, granul:u soils containing no more than 5 percent by weight finer than thc No. 200 sieve bascd on the fraction of the material passing No. 4 sieve. StrucWral fill should be placed in lifts no more than 10 inches thick in its loose state, with each lift compacted to at least 92% of the maximum dry density determined by AS'CM D1557 (Modified Proctor Method). LIU & ASSOCIATES, INC.