Simplified Seismic Slope Displacement Procedures

Simplified seismic slope displacement procedures are useful tools in the evaluation of the likely seismic performance of earth dams, natural slopes, and solid-waste landfills. Seismically induced permanent displacements resulting from earthquake-induced deviatoric deformations in earth and waste structures are typically calculated using the Newmark sliding block analogy. Some commonly used procedures are critiqued, and a recently proposed simplified procedure is recommended for use in engineering practice. The primary source of uncertainty in assessing the likely performance of an earth/waste structure during an earthquake is the input ground motion, so the proposed method is based on the response of several realistic nonlinear fully coupled stick-slip sliding block models undergoing hundreds of recorded ground motions. The calculated seismic displacement depends primarily on the ground motion’s spectral acceleration at the degraded period of the structure and the structure’s yield coefficient and fundamental period. Predictive equations are provided for estimating potential seismic displacements for earth and waste structures.