Seismic Translational Failure Analysis of MSW Landfills Using Pseudo-Static Approach

In the present study, the pseudo-static approach for seismic forces with limit equilibrium method is used to evaluate the seismic stability of typical side-hill type municipal solid waste (MSW) landfills in terms of translational mode of failure. Closed-form equations are developed for the upper and lower bound factor of safety values which gives the yield acceleration using the limit equilibrium method. Typical results of factor of safety for side-hill type MSW landfills with variations in waste material internal friction angle, base and back slope angle, horizontal and vertical seismic acceleration coefficients, subgrade slope angle, and interface friction angle have been reported. Results show that though the influence of horizontal seismic acceleration is significant on the factor of safety and the yield acceleration, the effects on vertical seismic acceleration are marginal. A typical comparison of the present pseudo-static results with the available case-specific static result has shown a good agreement.