Translational Seismic Failure Analysis of MSW Landfills Using Pseudodynamic Approach

Abstract

Most of the municipal solid waste (MSW) landfills can fail in different modes such as sliding, rotational, or translational mode under both static and seismic loading conditions. These landfills constructed in the seismic zones experience additional seismic inertial forces in both horizontal and vertical directions during earthquakes. The conventional pseudostatic method of analysis suffers from major limitations by not considering the dynamic nature of forces such as variation of seismic inertial forces with time, frequency and the effects of shear and primary waves in the analysis. The scope of this paper is to present the application of the modern pseudodynamic method for evaluating seismic stability of MSW landfills by using a translational failure mode. In the present analysis, closed-form solutions are developed for upper and lower ranges of the factor of safety against translational failure and the yield acceleration by using the limit equilibrium method for pseudodynamic forces. A parametric study is performed to evaluate the influence of variation of different parameters, such as backfill and face slopes, base inclination, soil friction angle, the interface friction angle, and the ratio of top width-to-height of landfill, on the factor of safety and the yield acceleration. The results obtained are compared with the static translational failure analysis results available in the literature.