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TECHNICAL MEMORANDUM <br /> Page 12 <br /> June 3, 1992 <br /> ® SAC31583.AC.ZZ <br /> Table 2 <br /> Summary of Static Safety Factors <br /> Long-term Final <br /> Refuse Buildout <br /> Section Failure Type (see plots, Appendix C) Static Safety Factor <br /> CS-A Block-type failure along smooth FML liner interface 1.3 <br /> Block-type failure along textured FML liner interface,unsaturated 3.0 <br /> Block-type failure along textured FML liner interface,saturated 1.6 . <br /> Circular-type failure search 2.4 <br /> Block-type failure along 2,300 psf shear strength layer (lean clay <br /> layer between elevation 0 and 10 feet) 2-3 <br /> CS-B Block-type failure along smooth FML liner and/or along 2,000 psf <br /> shear shear strength compacted clay liner in WMU E area 2.0 <br /> Block-type failure along textured, unsaturated FML liner and/or <br /> along 2,000 psf shear strength compacted clay liner in WMU E area 2.0 <br /> Block-type failure along textured, saturated FML liner and/or along <br /> 2,000 psf shear strength compacted clay liner in WMU E area 2-0 <br /> Circular-type failure search 1.8 <br /> Block-type failure along 2,300 psf shear strength layer(lean clay F <br /> layer between elevation 0 and 10 feet) 2.2 <br /> As shown in Table 2, a static safety factor of 1.3 was estimated for a smooth FML liner <br /> assuming an interface friction angle of 8 degrees, which is less than the recommended <br /> minimum safety factor of 1.5 for long-term final buildout conditions. For a textured FML <br /> liner, a static safety factor of 1.6 was estimated assuming saturated conditions with a friction <br /> angle of 9 degrees and a cohesion of 420 psf. Based on results of these preliminary analyses, <br /> we recommend that a textured FML liner be used for the proposed landfill extension. <br /> Assuming that a textured FML liner is used, the analyses indicate the cross sections meet the <br /> static stability design criteria for final buildout of the proposed landfill extension. The shear <br /> strength of the textured FML/clay lining interface should be determined by laboratory and/or <br /> field testing to confirm that the assumed textured FMIjclay interface friction angle shown in <br /> Table 1 is feasible. <br /> Results of Seismic Stability Analyses <br /> A yield acceleration of 0.148 was estimated for the block-type failure along the textured <br /> FML liner (saturated conditions) for Section -A. As previously discussed, the estimated <br />