Seismic stability analyses for landfill cover systems under different seepage buildup conditions

Drainage of landfill cover systems is often inadequate and buildup of seepage forces can occur over time. However, in most design analyses the seepage buildup is neglected and assumed to have only a minor impact on the seismic performance of landfill cover systems. Actually, simply ignoring the seepage buildup will lead to serious overestimation of the factor of safety. A new two-wedge method was developed to analyze the seismic stability of landfill cover systems under different seepage buildup conditions. The solutions of the factor of safety and the yield acceleration coefficient can be obtained, and the permanent displacement of landfill cover systems can also be calculated using the Newmark method. Based on the developed seismic analysis method, the effects of a parametric variation on the seismic stability and permanent displacement of landfill cover systems are presented.