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Page 3 <br />November 3, 2014 <br />• 2 residential farming structures <br />Owner: Cache la Poudre Irrigation Company <br />• Weir on the Greeley Number 2 Canal <br />Owner: Poudre Valley REA <br />• Power lines /power line poles <br />Stability Analyses <br />Mr. Eric Scott <br />Colorado DRMS <br />Stability analyses were performed in order to evaluate potential for damage to existing <br />permanent structures due to mine highwall slope failures. Analyses were performed with <br />Slope/W 2012 v. 8.12.3.7901 computer program. For each case we analyzed the most <br />critical soil profiles based on exploratory boring data (i.e. tallest highwall, shortest highwall <br />ledge, thickest overburden, etc.). <br />The stability analyses were run in accordance with accepted geotechnical standards and <br />DRMS requirements for temporary pit slopes summarized as follows: <br />• Mine highwalls were modeled as vertical slopes <br />• Residual soil strength parameters used for the upper 2.5 feet of weathered bedrock <br />• Factor of Safety must be greater than 1.0 <br />Groundwater levels on the profiles were modeled with anticipated maximum elevations to <br />portray anticipated site conditions. <br />Laboratory strength tests were not performed on soils from the site. The soil strength <br />parameters used were based on typical values from the anticipated soils and our experience <br />working with DRMS at other sites. The input strength parameters are displayed in Table 1. <br />Table 1. Stability Analysis Strength Parameters <br />Material <br />Unit Weight <br />(pct) <br />Effective <br />Cohesion <br />Effective Friction <br />Angle (deg) <br />Sand and gravel <br />125 <br />0 <br />35 <br />Overburden <br />122 <br />0 <br />27 <br />Shale Bedrock <br />120 <br />100 <br />30 <br />GE <br />