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FORWARD/AUSTIN LANDFILL <br />0 CLASS H <br />SEISMIC INDUCED PERMANENT DISPLACEMENT EVALUATION <br />FINAL COVER <br />PROCEDURE USED- BRAY AND RATHJE (1998) <br />INPUT DATA: <br />SITE CONDITION- DEEP COHESIONLESS <br />FILL HEIGHT, H - 160 ft. <br />AVERAGE SHEAR WAVE VELOCITY FOR FILL, VS - 1000 ft/sec <br />EARTHQUAKE MAGNITUDE for the MCE - 7.9 (associated with San <br />Andreas Fault at —65 miles) <br />MAXIMUM HORIZONTAL ROCK ACCELERATION, AR - 0.09g <br />NONLINEAR RESPONSE FACTOR (NRF) - 1.4 (for deep cohesionless soil <br />Profile from Bray & Rathje, 1998) <br />Thus, Site acceleration MHA = AR x NRF = 1.4x 0.09 = 0.13 g <br />SIGNIFICANT DURATION — D5_95 - —45.4 Sec. (for the Mag. 7.9 <br />earthquake) <br />YIELD ACCELERATION, ky - 0.15g (from pseudo -static <br />analysis) <br />CALCULATION: <br />MEAN PERIOD OF SHAKING, for the MPE T,,, = 0.62 Sec. (Bray et al ,1998), <br />PREDOMINANT PERIOD OF FILL - <br />RATIO Ts/ T. = 0.64/0.62 = 1.03 <br />TS = 4H/VS <br />.u= 4x160/1000 0.64 sec <br />RATIO MHEA/MHA = 1.0 (from Bray and Rathje (1998), Figure 8b for sand sites) <br />Where- MHEA — Maximum Horizontal Equivalent Acceleration of the fill <br />MHA Maximum Horizontal Site Acceleration <br />Thus, MHEA = 1.0 x MHA <br />= 1.Ox 0.139 = 0.13 <br />or, kmax = 0.13 <br />Ratio ky / kmax = 0.15/ 0.13 = 1.15 <br />Since ky/k,,,,, is greater than 1, significant displacement is not anticipated. <br />