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I <br /> 3. Where trenches are outside existing or future structures,paved areas, road shoulders, <br /> driveways or sidewalks, or where designated on plans or specified elsewhere,the trench <br /> backfill shall be Class A and pipe zone backfill in these areas shall be Class B. For these <br /> locations, compaction of Class B backfill shall be to not less than 90 percent of maximum <br /> density at optimum moisture content. Class B backfill shall be compacted to not less than <br /> 95 percent of maximum density at optimum moisture content. <br /> E. Employ placement method that does not disturb or damage nearby or adjacent foundation <br /> perimeter drainage or utilities in trench. <br /> F. Do not use power-driven impact compactors to compact pipe zone material. <br /> G. Backfill Immediately: All trenches and excavations shall be backfilled immediately after pipe <br /> or conduit is in approved condition to receive it and shall be carried to completion as rapidly <br /> as possible,unless otherwise directed by the Engineer. <br /> H. Under no circumstances shall water be permitted to rise in open trenches after pipe has been <br /> placed. <br /> I. Do not allow backfill material to free fall into the trench or allow heavy, sharp pieces of <br /> material to be placed as backfill until after at least 2 feet of backfill has been provided over <br /> 111 the top of pipe. <br /> J. Use hand compactors for compaction until at least 2 feet of backfill is placed over top of pipe. <br /> Thoroughly tamp each lift,including area under haunches,with handheld tamping bars <br /> supplemented by"walking in"and slicing material under haunches with a shovel to ensure <br /> that voids are completely filled before placing each succeeding lift. <br /> K. Placement of Sand: <br /> 1. Place medium sand in lifts not exceeding 8 inches in uncompacted thickness. <br /> 2. Compact each lift to a minimum of 95 percent relative compaction prior to placing <br /> succeeding lifts. <br /> • <br /> L. Placement of CLSM: <br /> 1. Discharge from truck-mounted drum-type mixer into trench. <br /> 2. Place in lifts not exceeding 2 feet in thickness. <br /> 3. No compaction of CLSM is allowed. <br /> 4. Use steel plates to protect the CLSM from traffic a minimum of 24 hours. After 24 hours, <br /> the CLSM may be paved, or opened to traffic until permanent surface restoration is <br /> completed, if it has hardened sufficiently to prevent rutting. <br /> M. New trenching shall not be started when earlier trenches need backfilling or the surfaces of <br /> streets or other areas need to be restored to a safe and proper condition. <br /> N. Do not leave trench open at end of working day. <br /> Legion Golf Course Stormwater Detention Project Trenching <br /> WO#UP3620 31 23 17- 17 <br />