bank
Civil/Environmental
- Jan 7, 2003
- 74
We designed an underground detention system using 30" HDPE pipe. According to our details and ASTM 2321 the trench is supposed to have a minimum clearance between the pipe and the trench wall of 10", backfilled with compacted Class I or II material. The contractor instead set the pipe in a trench almost exactly the width of the pipe OD. In-situ soil in this area is generally fat clay.
When we told him he had to take the pipe out of the ground, widen the trench, and provide the required backfill he asked if he could leave the pipe in place, widen the trench as required, and backfill and compact the Class I or II material. My question is can this work? Can they widen the trench 10" on either side of the HDPE pipe without damaging it, and achieve the required compaction such that the pipe is adequately supported laterally?
When we told him he had to take the pipe out of the ground, widen the trench, and provide the required backfill he asked if he could leave the pipe in place, widen the trench as required, and backfill and compact the Class I or II material. My question is can this work? Can they widen the trench 10" on either side of the HDPE pipe without damaging it, and achieve the required compaction such that the pipe is adequately supported laterally?
