1033 51ST PL SW Geotech Report 2022-10-28

• When used as structural fill,the on-site soil should be placed in lifts with a maximum uncompacted thickness of 10 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D1557. 9.2 IMPORTED GRANULAR MATERIAL Structural fill placed for general site grading in improved areas should consist of clean, free-draining granular soil(sand and gravel) that is free from organic matter or other deleterious and man-made materials, with a maximum particle size of 3 inches and a maximum fines Content of 5 percent by dry weight passing the U.S.Standard No. 200 sieve. The use of granular, free-draining material will increase the workability of the material during the wet season and the likelihood that the material can be placed and adequately compacted. Imported granular material used for structural fill should be naturally occurring pit-or quarry-run rock, crushed rock, or crushed gravel and sand and should meet the specifications provided in WSS 9-03.14(1) -Gravel Borrow, with the exception that the percentage passing the U.S. Standard No.200 Sieve does not exceed 5 percent by dry weight. Structural fill should be placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D1557. 9.3' STABILIZATION MATERIAL Stabilization material for temporary roads or to backfill over-excavations below structures should consist of imported shot rock, quarry spalls, or crushed ballast. The material should have a maximum particle size of 6 inches, have less than 5 percent by dry weight passing the U.S. Standard No. 4 sieve, and have at least two mechanically fractured faces. The material should be free of organic matter and other deleterious material. Materials that meet the specifications provided in WSS 9-13.7(2)-Backfill for Rock Wall,WSS 9-13.1(5) -Quarry Spalls, or WSS 9-27:3(6) Stone are"generally acceptable for use.•Stabilization material should be placed in lifts between 12 and 18 inches thick and compacted to a firm.condition using the bucket of an excavator or with a smooth-drum roller without using vibratory action. • 9.4 DRAIN ROCK Drain rock used in subsurface drains or against retaining walls should consist of granular material with a maximum particle size of 1 inch and should meet the specifications provided in WSS 9-03.12(4) -Gravel Backfill for Drains. The material should be free of roots, organic matter, and other-unsuitable materials;have less than 2 percentby-dry-weight passing the U.S. Standard No. 200 sieve(washed analysis); and have at least two mechanically fractured faces. 9.5 FLOOR SLAB AND PAVEMENT BASE ROCK Imported granular material used as aggregate base for floor slabs, pavement, and beneath hardscape areas should consist of 114-inch-minus material meeting the specifications provided in WSS 9-03.`9(3) -'Crushed`Surfacing;"Base Course,with-the exception that the aggregate should have less than 5 percent by dry weight passing the U.S. Standard No. 200 sieve and at least two mechanically fractured faces. The imported granular material should be placed in lifts with a maximum uncompacted thickness of 12'inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D1557. CffligDI=SIGNz 11 NWHome-1-01:1 O161 s