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Table 1 - Soil Properties <br /> Description Max dry Saturated Cohesion Internal <br /> density Density (psf) Friction <br /> c c Angle <br /> Sand and Gravel 110 125 0 35 <br /> Clay 107 130 50 24 <br /> Stable Bedrock 125 141 2000 20 <br /> Slurry Wall 1 100 1 110 0 45 <br /> DESIGN ANALYSIS AND CRITERIA <br /> The proposed mining slopes were analyzed using Clover Technologies Galena Slope <br /> Stability Analysis System, version 7.2. 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. The USGS peak <br /> acceleration map is included in Appendix E. A peak acceleration factor of 0.10 x gravity <br /> was taken from this data. A conservative earthquake loading coefficient of 0.50 x PHA is <br /> often used for slope stability analyses (50% of PHA). We used an even more <br /> 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:1V. <br /> Six cases were analyzed where the mining is adjacent to man-made structures. The <br /> locations of the cases are shown on the case location map included in Appendix A. <br /> Case 1 — Fence West of Pit. <br /> The mining operation is adjacent to a fence near the west property line of the site. The <br /> proposed setback for mining is 20 feet from the fence. The mining depth was assumed <br /> to be 90 feet in this area based on bore log information. <br /> Case 2 — Fence North of Pit. <br /> The mining operation is adjacent to a fence near the north property line of the site. The <br /> proposed setback for mining is 11 feet from the fence. The mining depth was assumed <br /> to be 108 feet in this area based on bore log information. <br /> J-2 Contracting Company—Sunset Industrial Pit <br /> J&T Consulting, Inc. Slope Stability Analysis <br /> Pageg <br />