Stability analysis of landfill cover systems considering reinforcement

A cover system is reinforced with a geogrid to meet stability demands in extremely adverse scenarios. In analyzing the stability of a cover system, the geogrid loads can be calculated by reducing its allowable long-term strength, which considers equilibrium only and ignores the strain coordination condition. In this paper, an analytical method is proposed to estimate geogrid loads in a landfill cover system. This method provides an appropriate solution that considers strain compatibility ignored by other models and that can be used easily. Furthermore, a new method was developed to analyze the stability of cover systems under different seepage build-up conditions. Parametric studies indicate that the stiffness of the cover soil and geogrid, or the stiffness ratio between the two, seepage build-up conditions, slope geometry and interface shear strength significantly affect the stability of the cover soil. Comparing the results from the method proposed in this paper with those from the existing method obtained in previous studies, the approach proposed herein was found to better fit the actual.