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Based on analysis of material removed from the mine the following <br /> particle size distribution was obtained. <br /> Size Distribution <br /> Material above 6" 20% by weight <br /> Material above 4" 30% by weight <br /> Material above 2" 30% by weight <br /> Material above #4 mesh* 10% by weight <br /> Material above #10 mesh* 5% by weight <br /> Material above #40 mesh* < 5% by weight <br /> Material above #200 mesh* < 5% by weight <br /> * U.S. Series equivalent screen size <br /> This information was provided by National King Coal <br /> Limited information on material strength currently exists. The <br /> following table summarized this data. This information was supplied <br /> by National King Coal. <br /> Material Strength <br /> Relative toughness = 1.5 <br /> Ft-lb/ft2 of fracture = 312 .4 <br /> Compressive strength, 9500 psi (no partings) <br /> Compressive strength, 8400 psi (partings) <br /> Compaction 12.5$ <br /> In order to complete an accurate stability analysis the shear <br /> strength of the fill material is needed. Due to time and field <br /> constraints it was not possible to complete these test prior to the <br /> submittal of this technical revision. Therefore the approach taken <br /> in this analysis was to conservatively estimate the shear strength <br /> based upon the type of material as described above (USBR, 1973 and <br /> Huang, 1983) . Furthermore, conservative estimates of all other <br /> design parameters were used to assure stability. The estimated <br /> shear strength values are, <br /> Effective Cohesion Coefficient = c = 0. 1 tsf <br /> Effective Friction Angle = 0 = 300 <br /> 3 <br />