A finite-volume numerical model for bio-hydro-mechanical behaviors of municipal solid waste in landfills

A bio-hydro-mechanical model is developed to describe interactions between leachate flow, landfill gas flow and waste deformation. The model is developed based on three-phase consolidation theory; and the governing equations are solved by finite volume method. The proposed model is effectively validated by two well-designed laboratory tests. The simulation results for a typical conceptual landfill demonstrate that ignoring the waste consolidation yields a little bit smaller leachate and gas pressures, as well as smaller waste deformation, neglecting landfill gas generation and flow will distinctly underestimate the leachate pressure and then overestimate the effective stress, which may eventually cause slope failure.