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As each length of pipe is placed in the trench, the joint shall be assembled and the pipe <br /> brought to correct line and grade . At times when pipe laying is not in progress , the <br /> open end of the pipe shall be closed by a watertight plug . When practical, the plug <br /> shall remain in place until the trench is pumped completely dry . When it is <br /> necessary to deflect the pipe from a straight line in either the vertical or horizontal <br /> plane, or where long radius curves are permitted, the amount of deflection shall <br /> not exceed that of Table 5 and 6 in AWWA Specification C600 for ductile iron <br /> pipe or AWWA M23 for P .V . C . pipe . <br /> 1 ) Thrust Restraint - All valves , dead ends, tees , and bends for changes in <br /> alignment shall be appropriately restrained against pipeline thrust. All items <br /> installed in the mainline which may cause vertical or horizontal thrust forces <br /> shall require the item and appropriate length of upstream and <br /> downstream pipe to be mechanically restrained with approved devices . <br /> 2) Backfill <br /> a. General - Where the trench has been dewatered, backfilling must <br /> progress sufficiently before pumps are shut off to prevent flotation of <br /> pipe . Any pipe that has been displaced perceptibly from its correct position <br /> shall be removed and re-laid properly at the. Contractor' s expense. <br /> Backfilling shall follow pipe laying within 100 feet, unless otherwise <br /> directed by the Engineer, but shall not be performed in any case until the <br /> Engineer has approved the line for backfilling . Water shall not be added <br /> except as required to obtain Optimum Moisture Content and " flooding " <br /> or "puddling" for compaction will not allowed . <br /> Backfill material shall be free of roots, logs, limbs , clays, large rocks or any <br /> material or debris determined to be unsuitable by the Engineer. The Engineer <br /> may reject any material which he considers unsuitable for backfill . <br /> The compaction procedures specified herein shall be considered <br /> " minimum procedures" to prevent after-settlement and the Contractor shall <br /> reopen, refill and recompact any trenches indicating improper backfill <br /> procedures or after-settlement. <br /> All road crossings shall be backfilled immediately, made passable and <br /> maintained passable until the permanent repair is made . <br /> b . State-Owned Rights-Of-Way Under Pavements - The initial lift (stage 1 ) <br /> shall consist of clean, fine, select materials, not exceeding 3 /4 " in diameter <br /> under the haunches of the pipe . The material shall be placed in layers not <br /> to exceed 6 " . The initial lift shall be manually compacted to 100% of <br /> the maximum density as determined by AASHTO T-99 . Subsequent lifts <br /> (stage 2) to 12 " above the pipe shall be constructed as specified for stage 1 , <br /> except that had operated mechanical tampers may be used . Additional lifts in <br /> stage 2 , from 12 " above the pipe to the top of subgrade shall be carefully <br /> backfilled with material free from organic material and stones or clumps <br /> C :\Download\techspec-02501 . doc SC501 - 9 <br />