Laserfiche WebLink
FORWARD/AUSTIN LANDFILL <br />® CLASS H <br />SEISMIC INDUCED PERMANENT DISPLACEMENT EVALUATION <br />CROSS-SECTION Fl. <br />:1 <br />U <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 - 0.098 (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- Ts = 41VVS <br />=4x160/1000 = 0.64 sec <br />RATIO Ts/ T. = 0.64/0.62 = 1.03 <br />RATIO MHEA/MHA = 0.43 (from Bray and Rathje (1998), Figure 7b for sand sites) <br />Where- M1I IEA — Maximum Horizontal Equivalent Acceleration of the fill <br />MHA Maximum Horizontal Site Acceleration <br />Thus, MHEA = 0.43 x MHA <br />= 0.42x 0.13g = 0.06 <br />or, k.,,., = 0.06 <br />Ratio ky / k1111* = 0.09/ 0.06 = 1.5 <br />Since ky/kma,; is greater than 1, significant displacement is not anticipated. <br />