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FORWARD/AUSTIN LANDFILL <br />! CLASS II <br />SEISMIC INDUCED PERMANENT DISPLACEMENT EVALUATION <br />CROSS-SECTION Fl <br />C <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 - 6.7 (associated with Great <br />Valley Fault at 21 miles) <br />MAXIMUM HORIZONTAL ROCK ACCELERATION, AR - 0.13g <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 = l Ax 0.13 = 0.18 g <br />SIGNIFICANT DURATION – 135-95 <br />CALCULATION: <br />- –15.3 Sec (for the Mag. 6.7 <br />earthquake) <br />0. 9g (from pseudo=static <br />analysis) <br />-MEAN PERIOD OF SHAKING, for the WE T,t — 0:50 Sec. -,(Bray et al ,19.98), <br />PREDOMINANT PERIOD OF FILL- TS = 411/VS <br />= 4x160/1000 = 0.64 sec <br />RATIO Ts/ T,,, = 0.64/0.50 = 1.28 <br />RATIO MHEA/MHA = 0.40 (from Bray and Rathje (1998), Figure 7b for sand sites) <br />Where- MHEA – Maximum Horizontal Equivalent Acceleration of the fill <br />MHA Maximum Horizontal Site Acceleration <br />Thus, MHEA = 0.40 x MHA <br />= 0.40x 0.18g = 0.072 <br />or, k,,,ax = 0.072 <br />Ratio ky / k,,,a, = 0.09/ 0.072 = 1.25 <br />Since ky/k,,,a,; is greater than 1, significant displacement is not anticipated. <br />