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Scenario <br />Density <br />Cohesion <br />Internal Angle of Friction <br />Safety Factor <br />Tailings <br />1 <br />103Ibs /ft' <br />0.7 <br />32° <br />1.98 <br />2 <br />103 Ibs/ft' <br />0.7 <br />32° <br />1.93 <br />3 <br />103Ibs /ft' <br />0.56 <br />26° <br />1.50 <br />Waste Rock <br />110 lbs/ft' <br />0 <br />45° <br />almost exclusively tailings, and with the cohesion and internal angle of friction being reduced by <br />20% from the text values for an ML class soil. SB -Slope calculated the Safety Factor as 1.50 for <br />this scenario. Figure U -6 shows the failure circle for this Safety Factor. <br />Table U-1 — Revenue Waste Pile Slope Stability Analyses Comparison <br />Note: Waste rock values remain the same in all the scenarios. Soil class table from Huang attached at the end of the exhibit. <br />Even when the cohesion and internal angle of the tailings are reduced by 20 %, the Safety Factor for <br />the Revenue waste pile is above 1.3, which is considered the lowest allowable slope Safety Factor. <br />Atlas Waste Pile <br />Scenario 1 <br />The waste rock in place at Revenue on the Atlas waste pile is regarded as shown on Map C -2, and <br />the waste pile is built to the final specifications in the reclamation plan and shown on Map F -1. The <br />bedrock beneath the existing ground in the Atlas waste pile area is estimated to be 10 feet below <br />the current surface. Based on the reclamation plan and baseline topography, a profile of the waste <br />pile, the baseline topo, and the estimated bedrock was created. This was then used to generate <br />geometry for the slope stability program SB- Slope. Figure U -7 shows the profile. <br />For Scenario 1, geometry of the waste pile based on the overall slope derived from the profile was <br />used. The pile was designed with 3H:1V maximum slopes with periodic 10 foot wide catch <br />benches. The overall slope of this design ends up being —4H:1 V. This scenario was modeled in SB- <br />Slope using the same material properties as shown in the Revenue waste pile Scenario 1. Figure U- <br />8 shows the geometry used in SB- Slope. <br />Revenue Mine November 2012 U - <br />