Laserfiche WebLink
0 <br /> <br />psf. This strength value was used in the stability analysis for saturated overburden <br />soils or embankment soils. <br />The Naval Facilities Design Manual (NAVFAC DM-7) provides typical properties <br />of compacted materials (Table 9-1) based upon USER data. The data for clayey <br />sands and clay soils (as-compacted, un-saturated) showed friction values of 28 to 31 <br />degrees and cohesion of 1,550 to 1,800. Based upon our experience at the site and <br />the above reference, we selected a strength value of 15 degrees friction and 1,500 <br />psf cohesion for compacted embankment soils above the water level. <br />Based upon our understanding of conditions and our experience at the site, <br />we believe the above friction and cohesion values are reasonable but conservative <br />estimates of strength for clayey overburden and embankment soils. <br />• STABILITY ANALYSIS <br />The two conceptual sections shown on Figs. 1 and 2 were analyzed to <br />evaluate the factor of safety on the interior and exterior slopes. The results of <br />stability analysis along with soil properties assumed in the analysis are presented on <br />Figs. 3 through 6. The stability analysis was performed using SlopelW software by <br />Geo-Slope International, Ltd, Version 3.0. The results are summarized in the <br />following table. <br />TABLE A <br /> <br />Factor of Safety <br />Group I <br />Taller Sections Group II <br />Smaller Sections <br />Interior Sloe Exterior Slope Interior Sloe Exterior Slope <br />2.0 2.2 3.0 3.1 <br />COLOWYO COAL COMPANY, LP <br />STABILITY EVALUATION -SEDIMENTATION PONDS <br />CTLlT 28,731 <br />5 <br />