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Table 1 - Soil Properties <br /> Description Max dry Saturated Cohesion Internal <br /> density Density (psf) Friction <br /> cf cf Angle <br /> Overburden 110 131 150 22 <br /> Sand and Gravel 110 125 0 35 <br /> Clay 107 130 50 24 <br /> Weathered 125 141 100 18 <br /> Bedrock <br /> Stable Bedrock 125 141 1 2000 20 <br /> Slurry Wall 100 110 0 45 <br /> DESIGN ANALYSIS AND CRITERIA <br /> The proposed mining slopes were analyzed using Clover Technologies Galena Slope <br /> Stability Analysis System, version 7.1. Galena was designed to analyze the slope <br /> stability of earth embankments subjected to several critical situations that may occur <br /> during the life of the embankment. For this project, eleven cases were identified as <br /> critical during the mining operation. Static and pseudo-static conditions were analyzed <br /> in each case. <br /> Pseudo-static peak acceleration factors (peak horizontal acceleration, or PHA) were <br /> taken from USGS information for the western United States. The 2% probability of <br /> exceedance in 50 years (the most conservative) was used. A peak acceleration factor of <br /> 0.10 x gravity was taken from this data. A conservative earthquake loading coefficient of <br /> 0.50 x PHA is often used for slope stability analyses (50% of PHA). We used an even <br /> more conservative approach and used 70% of the PHA for this area for our earthquake <br /> loading coefficient. Hence, 0.70 x 0.10 = 0.07. <br /> All mining side slopes will be 3H:1 V. <br /> Case 1 — Wetland West of Reservoir 1. The mining operation is adjacent to a <br /> wetland near the west property line of the site. The proposed setback for mining <br /> is 65 feet from the east boundary of the wetland. The mining depth was assumed <br /> to be 90 feet in this area based on bore log information in the geotechnical <br /> report. <br /> Case 2 — Cache La Poudre River. The mining operation is adjacent to the <br /> Cache la Poudre River on the north side of the mining site. The mining depth was <br /> assumed to be 80 feet in this area based on bore log information in the <br /> geotechnical report. The minimum mining setback was set 150 feet from the river <br /> bank. <br /> Case 3 — Cache La Poudre River. The mining operation is adjacent to the <br /> Cache la Poudre River on the north side of the mining site. The mining depth was <br /> J-2 Contracting Company-DPG Pit <br /> Slope StabilityA <br /> J&T Consulting, Inc. Page'2 <br />