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ECOSA Evaluation AdrianBrown <br />tracked equipment or the personnel operating them, nor to any person or equipment at the base of the <br />slope. <br />3.5.2 After Reclamation <br />The ECOSA will be reclaimed with a slope of 2.5:1 (22 °). The geotechnical stability of the ECOSA was <br />evaluated in a manner consistent with that of previously approved documents and with the SGOSA <br />Extension discussed above. In summary, the key input parameters derived from extensive boring, <br />sampling, testing, and observation remained the same: <br />• Effective stress friction angle for overburden = 39° <br />• Effective stress friction angle for foundation colluvium = 29° <br />• Moisture condition in slope = dry <br />• Pseudo - static peak earthquake ground acceleration = 0.14 g <br />Some additional information has become available to further assess the strength of the foundation <br />colluvium as a result of testing of 106 samples performed on this material for use as an underliner for <br />the VLF. The evaluation of the friction angle is presented in Plate 9. This evaluation confirms the value <br />of 29° used for this parameter. <br />The Factors of safety ( "FOS ") for the ECOSA were derived for both static and pseudo- static conditions <br />using the Method of Slices analysis (Morgenstern and Price, 1965). The results are presented in Plate <br />10, and are as follows: <br />Factor of Safety under Static Loading = 1.66 <br />Factor of Safety under Earthquake Loading = 1.16 <br />Based on these results, the reclaimed ECOSA will be stable under all expectable conditions. <br />1385E.20120224 <br />