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page Two <br />7 January 2013 <br />M12058MT <br />Our analysis included an assessment of the theoretical <br />stability of embankment slopes manufactured from the materials <br />tested. The constructed embankment configuration is generally as <br />follows: <br />-- crest width, 10 feet, <br />- embankment height, 9.5 feet, <br />- embankment inclination: 3 horizontal to 1 vertical, up and <br />down stream slopes. <br />These dimensions imitate the embankment configuration used to <br />assess the theoretical calculated stability of the embankment <br />slopes. The scenario that was assessed included: <br />- full reservoir water level, <br />- a somewhat homogenous embankment fill, <br />- a saturated embankment, and <br />- steady state seepage flow through the embankment below the <br />phreatic surface within the embankment. <br />The stability of any slope is dependent on many factors. Typi- <br />cally the theoretical stability of a slope is analyzed by <br />calculating the anticipated gravitational forces that tend to <br />drive the mass of soil downhill and the anticipated internal <br />strength of the soil along the expected plane of failure that <br />will resist the downhill movements. If the driving forces are <br />equal to or greater than the resisting forces then failure is <br />imminent. We understand that the required minimum calculated <br />theoretical factor of safety is 1.3 for a normal pool with steady <br />state seepage, saturated condition. A calculated factor of <br />safety of 1.0 or less indicates that slope movement is imminent <br />or in process. <br />Factors that have an adverse influence on slope stability can <br />generally be classified as those that increase the stress <br />(driving force) on the system or those that decrease the strength <br />(resisting forces) of the soil. <br />i�#e� <br />CONSULTING GEOTECHNICAL ENGINEERS AND <br />MATERIAL TESTING <br />Appendix 2.05.3(4)-6 Page 8 December 2018 (TR -19) <br />