Laserfiche WebLink
BRAY, RATHJE, AUGELLO AND MERRY D Seismic Design for Lined Solid-Waste Landfills <br />220 GEOSYNTHETICS INTERNATIONAL S 1998, VOL. 5, NOS. 1-2 <br />Figure 11. Normalized base liner sliding displacements (from Bray and Rathje 1998). <br />0.0 0.2 0.4 0.6 0.8 1.0 <br />0.01 <br />0.1 <br />1 <br />10 <br />100 <br />1000 <br />10000 <br />ky /kmaxNormalized base liner sliding displacementU/(kmax)(D5-95) (mm/s) <br />Mw =6.25 <br />Mw =7.0 <br />Mw =8.0 <br />Median prediction <br />16% probability of exceedance <br />seismic coefficient,kmax (i.e.MHEA /g)can be estimated using Figure 6,and theseismi- <br />cally induced displacement,U, can be estimated using Figure 11. <br />Calculated earthquake-induced cover displacements, grouped according to Mw val- <br />ues, are shown in Figure 12. The results exhibit considerable scatter, emphasizing the <br />value ofproject-specific earthquake-induced deformation analysis ofcover systems. In <br />general, softerlandfills havelarger calculated cover displacements than stifferlandfills <br />due to more long-period motion amplification in the softer waste fill. Cover displace- <br />ments are significantly larger than those calculated for base sliding due to the higher <br />seismic loading experienced at the cover of the landfill. <br />Seismically induced displacements were found to vary systematically with site con- <br />ditions, with generally larger calculated displacements at deep, soft sites (Bray and <br />Rathje 1998). However, the larger displacements calculated at soil sites at a specified <br />ky /kmax ratio areoffsetbytheseismic loadingresultsdiscussedpreviously whichindicate <br />that soil sites produce lower kmax values for identical rock motions and landfill confi- <br />gurations. As the seismic loading and seismic displacement calculations vary predict- <br />ably with site conditions in opposite and nearly equal proportions, simplified analysis <br />based on the rock site results presented in Figures 6, 11, and 12 can be used for all site <br />conditions without introducing significant errors in the final displacement estimate. <br />Alternatively, a pseudo-static slope stability analysis may be performed with a seis- <br />mic coefficient calibrated with the preceding seismically induced permanent displace-