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<br />5/ 15/00 <br />- Trenched 26+30 [0 27+50. <br />- Backfilled 22+75 to 24+45. <br />-Could not clean trenching from previous day due to sloughing of overburden along trench <br />sides. <br />- Extensive sloughing during trenching has resulted in trench widths of 7 to 10 feet at surface. <br />This makes it very difficult to accurately check trench depths. <br />- Potential problem areas from 24+00 to 26+00 where bedrock key was tagged at less than 3 feet. <br />5/ 16/00 <br />- No work completed due to equipment problems. <br />5/ 17/00 <br />- Trenched 27+50 to 27+70 <br />- No backfilling <br />- Work day shortened by equipment problems and heavy rains. <br />5/ 18/00 <br />- Trenched 27+70 to 30+00. <br />- Backfilled 24+45 to 25+40. <br />- Desander in operation. <br />5/ 19/00 <br />- Trenched 30+00 to 31+70. <br />- Backfilled 25+40 to 26+75. <br />-Sloughing continues during trenching but we have been able to significantly reduce the <br />occurrence of sloughing after each trenching se[ is completed. Width of trench still makes it <br />difficult to accurately check trench depths. <br />-Potential problem areas from 28+50 to 30+00 where bedrock key was tagged at less than 3 feet. <br />- Desander in operation. <br />5/20/00 <br />- Trenched 31+70 to 33+00. <br />- Backfilled 26+75 to 28+75. <br />- Potential problem area from 32+50 to 32+60 where sloughing occurred beyond the reach of the <br />trenching backltoe. <br />- Desander in operation. <br />Conclusions: <br />Construction progress has improved. However, due to thinning of [he overburden along the south <br />side of the project, the overburden has been sloughing during and after completion of trenching in <br />some areas. We are trying to control the amount of sloughing material [hat falls into the trench <br />by removing any unstable areas of overburden before the completion of each trenching set. <br />Several areas of the bedrock key along the south side have tagged at less than 3 feet. This may be <br />