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• <br />WE <br />toward the spoil toe where the water exits at areas of least resistance. <br />These areas are indentified by the springs or seeps observed and <br />delineated on Fig. 2. <br />Field density tests were made at several test pit locations to <br />evaluate bulk density of the in -place spoil. The results of density <br />tests are presented on the Logs of Exploratory Test Pits, Fig. 4. The <br />tests were performed using a sand cone with a diameter of 12 inches. The <br />results of our testing indicate in -place bulk dry densities varying be- <br />tween 87 and 1 -05 pounds per cubic foot. Most of the field moisture <br />contents of the granular spoil were between 6.7 and 9.7 percent. The <br />predominantly clay spoil had higher field moisture contents (12.3 per- <br />cent). <br />LABORATORY INVESTIGATION <br />Our laboratory investigation consisted of a review of previous work we <br />performed for the Colorado Yampa Coal Company within the Eckman Park Develop- <br />ment and a review of strength testing performed by Science Applications, Inc. <br />of Steamboat Springs on rock cores obtained for the proposed Twenty Mile Mine. <br />We performed direct shear tests and gradation analyses on materials obtained <br />from test pits to better evaluate the characteristics of the on -site materials. <br />Samples of spoil obtained from field density testing were subjected to <br />gradation analyses (Appendix A, Figs. A -1 through A -4). The tests indicate <br />that the angular spoil precominantly includes particles in the fine to coarse <br />gravel sizes. Most of the samples contained 25± percent particles smaller <br />than the No. 200 sieve size. <br />