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A force limit equilibrium stability analysis was completed using the SLOPFJW software package. A <br />Morgenstern Price analysis was used in conjunction with a search routine to estimate the lowest safety <br />factor for the embankment. This method satisfies both moment and force equilibrium of a given analysis. <br />For the worst case scenario, embankment geometry with the following characteristics was used: <br />• Embankment Crest Width: 5 feet <br />Downstream Slope Heigh: 9 feet <br />• Downstream Slope Angle: 2H:1 V <br />• Upstream Slope Height: 8 feet <br />• Upstream Slope Angle: 2H:1 V <br />• Height from Spillway Invert to Upstream Slope Tce: 5 feet <br />This geometry is illustrated by SLOPFJW output shown on Figure 13-A, Stock Tank Stability. <br />The embankments will be constructed from spoil material produced during mining. This material is placed in <br />wntrolled lifts and compacted. Based on this fad, observations of the on-site spoil piles, and typipl <br />sVength values for spoil material, the following strength properties were assigned to the embankment. <br />• Spoil: ~= 38°, cohesion = 0 psi <br />• UnA Weight: 120 pd <br />• Based on the above stated assumptions, safety factor of 1.56 was calculated by the limit equilibrium <br />analysis. Rule 4.05.9(8)(b) states that the stock tanks require a safety factor of 1.3. Therefore, these <br />structures should perform adequately during the life of mine. In addition, stock tanks will be located so that <br />there are no potential safety hazards to downstream structures; therefore, 'd a failure did occur, there would <br />be minimal risk to Iffe and property. <br /> <br />MR-57 7b Revised 01105 <br />