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1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />i <br />1 <br />1 <br />1 <br />1 <br />1 <br />1 <br />Table 2. Slope Stability Analysis Results <br />Description Calculated <br />Factor of Safety Minimum <br />Factor of Safety <br />Dewatered mining highwall 1.207 1.2 <br />Case 1 - Steady state reclamation slope 1.647 1.5 <br />Case 2 - Rapid draw down reclamation slope 1.209 1.2 <br />Conclusions and Recommendations <br />Case 1 - The resulting factor of safety of 1.647 is above the minimum requirement of 1.5 for the <br />steady state case. The proposed reclamation embankment is satisfactory. <br />Case 2 - The resulting factors of safety of 1.207 and 1.209 are above the minimum requirement <br />of 1.2 for the rapid draw down case. The proposed mining and reclamation embankments are <br />satisfactory. <br />The following recommendations for monitoring of slope stability should be followed: <br />1. A visual inspection of the excavated highwalls should be done on a weekly basis for the <br />first 6 months of mining. This inspection should consist of walking the existing ground <br />and looking for any signs of stress cracks or other potential signs of slope failure. Some <br />minor sluffing of highwalls is expected on any mine site. The intent of this inspection is <br />to locate potential major slope failures that could potentially extend back into a structure. <br />2. A visual inspection should be done anytime after a major precipitation event that has <br />saturated the ground using the same procedures. A major precipitation event would be <br />defined as a storm that produces an intensity level reached once in 50 years on the <br />average. <br />3. If a visual inspection detects signs of potential slope failure, qualified personnel should <br />be contacted to evaluate and recommend remediation work to stabilize the area. <br />4. If no visible signs of slope failure are detected within the first 6 months, then the <br />inspection period could be reduced to once per month or after every major precipitation <br />event.