3400 RIVERFRONT BLVD Geotech Report 2022-10-25

• • • • • water from running down the slope face. Erosion control measures such as straw bales, • sediment fences, and temporary detention and settling basins should be used in accordance with local and state ordinances. • • 6.9 STRUCTURAL FILL • Structural fill includes fill beneath foundations, slabs, pavements, any other areas intended to • support structures, or within the influence zones of structures. Structural fill should be free of organic matter and other deleterious material and, in general, should consist of particles no • larger than 4 inches in diameter. Recommendations for suitable fill material are provided in the • following sections. 6.9.1 On-Site Soil • The on-site fine-grained soil will be suitable for use as structural fill only if it can be moisture • conditioned. Based on our experience, the silty soil is sensitive to small changes in moisture • content and may be difficult, if not impossible, to compact adequately during wet weather or • when their moisture content is more than a few percentage points above optimum. Available silty soil may require extensive drying if it is used as structural fill. The material should be • placed in lifts with a maximum uncompacted thickness of 8 inches and compacted to not less than 92 percent of the maximum dry density, as determined by ASTM D 1557. We recommend • using imported granular material for structural fill if the moisture content of the on-site soil • cannot be reduced. • The on-site coarse-grained soil will generally be suitable for use as structural fill. On-site coarse- • grained soil 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 D 1557. • • 6.9.2 Imported Granular Material • Imported granular material should be pit- or quarry-run rock, crushed rock, or crushed gravel . and sand that is fairly well graded between coarse and fine and has less than 5 percent by dry weight passing the U.S. Standard No. 200 Sieve. All granular material must be durable such that there is no degradation of the material during and after installation as structural fill. The • percentage of fines can be increased to 12 percent if the fill is placed during dry weather and • provided the fill material is moisture conditioned, as necessary, for proper compaction. The • 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 D 1557. During the wet season or when wet subgrade conditions exist, the initial lift • should have a maximum thickness of 15 inches and should be compacted by rolling with a • smooth-drum, non-vibratory roller. • 6.9.3 Recycled Concrete • Recycled concrete can be used for structural fill provided the concrete is broken to a maximum • particle size of 6 inches. This material must be durable such that there is no degradation of the • material during and after installation as structural fill. Recycled concrete can be used as trench backfill and pavement base rock if it meets the requirements for imported granular material, which would require a smaller maximum particle size. The material should be placed in lifts with • G EODESIGN= 17 Polygon-128-01:09161 5