Laserfiche WebLink
-17- <br /> Soil Type* A B C <br /> angle of internal 40 35 30 <br /> friction (degrees) <br /> moist unit weight (pcf) 150 130 110 <br /> ultimate active 0.22 0.27 0.33 <br /> pressure coefficient <br /> ultimate passive 4.6 3.7 3.0 <br /> pressure coefficient <br /> equivalent active 33 35 37 <br /> fluid density (pcf) <br /> equivalent passive 350 240 160 <br /> fluid density (pcf) <br /> equivalent net passive 330 220 150 <br /> fluid density (pcf) <br /> *Type A: dense unweathered till <br /> Type B: new unweathered till fill , compacted to 90 percent <br /> Type C: existing fill ; loose weathered till <br /> pcf- = pounds per cubic foot <br /> Playfield Drainage <br /> Considering the anticipated low permeability of existing in place soils <br /> and of newly placed compacted fill , a drainage layer beneath the playing <br /> surface is recommended. We understand that a drainage system is being <br /> designed by C. H. Huhn & Associates under a separate contract. <br /> Pavement Design <br /> As previously recommended, subgrade in areas to be paved should consist <br /> either of recompacted inorganic native soil , or at least 2 feet of new <br /> fill compacted to at least 95 percent relative compaction. For the <br /> recommended subgrade preparation, a pavement section of 2 inches of <br /> asphaltic concrete over 4 inches of crushed rock base is appropriate for <br />