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ICI <br /> <br />TABLE B <br />SUMMARY OF STABILITY ANALYSIS <br />• <br />Case General Conditions Factor of Safety <br />I Downstream slope, 3.0 <br /> No water, <br /> Clay embankment, <br /> Clay foundations soil. <br />II Same as 1, <br /> Sand foundation soil. 2.2 <br />III Upstream slope, 5.4 <br /> Maximum water storage, <br /> Clay embankment, <br /> Clay foundation soils. <br />IV Same as III, <br /> With sand foundation soils. 3.0 <br />V Downstream slope, 2.4 <br /> Maximum water storage, <br /> Clay embankment, <br /> Clay foundation soils. <br />VI Same as V, <br /> With sand foundation soils. 1.7 <br />We considered seepage and piping below the embankment cross sections. <br />The ponds have relatively low levels of permanent water/sediment storage of less <br />than 5 feet. The height of anticipated water/sediment storage was previously <br />summarized in Table A. We utilized the weighted creep ratio method as outlined in <br />Soil Mechanics and Engineering Practice, Terzaghi & Peck, John Wiley 8 Sons, Inc., <br />1967, to evaluate the potential for piping. At four of the embankment locations the <br />weighted creep ratio was above 8.5, which indicates a very low probability of piping <br />for very fine sand or silt soils which is a worst case condition. At Ponds 004 and 006 <br />the weighted creep ratios were on the order of 4 to 5 which theoretically could <br />indicate some concern regarding piping of fine sand soils. However, at these two <br />• pond locations clayey sand and clay soils are anticipated. These materials are <br />LORENCITO COAL COMPANY, LLC <br />SMALL SEDIMENTATION EMBANKMENTS <br />CTLR 26,559 9 <br />