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Dames ~ Moore • Flatiron Companies May 17, 1982 Page 7 The excavated materials are hauled to the East Dump area in scrapers and dumped in layers on the order of 6 to 12 inches thick. The layers will not exceed these thickness due to limitations of the scrapers being used (i.e., the "pan" cannot be raised more than about 12 inches off the ground). The scrapers use a systematic change of route with each load such that the material placed in the previous few loads is compacted by the scraper wheels. In addition, a single blade grader is used to smooth and level rough areas. ENGINEERING CHARACTERISTICS The excavation and filling procedures being used are producing a reason- ably well compacted fill. In addition, the various types of material ex- cavated are being mixed such that the fill is fairly homogeneous. As a result the chance of having a localized zone of weakness in the fill is remote. n ~_J Two density tests were performed and confirm that reasonable compaction is being attained. The field tests in the East dump fill indicate compaction of 67 and 90 percent of maximum dry density per ASTM D 1557-70 META. C. The first test (67 percent) was performed in an area just graded and run over by scrapers only once or twice. This area was to be further compacted by the scrapers. The second test (90 percent) was in an area that had been run over numerous times and was ready for an additional layer of fill to be placed. In order to confirm our judgement that the East Dump will be stable several strength tests were conducted on recompacted (78 percent of maximum dry denaity) samples of fill material. The results from these tests are presented in the Attachment. These results were utilized to estimate shear strength parameters for the fill material for use in slope stability calculations. A summary of the shear strength parameters selected is presented on Table 1. Based on the steepest planned elope angle (i.e. 5 horizontal to 1 vertical) •