Effects of Leachate Recirculation Systems on Slope Stability of Bioreactor Landfills: Fid-Bau Portal

Effects of Leachate Recirculation Systems on Slope Stability of Bioreactor Landfills

Avinash, Lagudu S. / Mishra, Anumita

In the present study, numerical analysis was carried out using the finite element method to investigate the effects of liquid injection on the slope stability of landfills for heterogeneous anisotropic waste conditions. The numerical model was validated with the previously published literature for homogeneous and heterogeneous anisotropic waste conditions. The leachate recirculation was simulated for two different methods, i.e., horizontal trenches and vertical wells, with varied injecting leachate recirculation pressures. Based on the analysis, the moisture distribution achieved by these two systems was evaluated using degree of saturation and pore water pressure, and their effects on slope stability were investigated. High-pressurized leachate injections have adverse effects on the stability of landfills. The pore pressure developed in the landfill due to leachate injection is greater for the horizontal trench system in comparison to the vertical wells. The degree of saturation in the top layers of the landfill was greater in the horizontal trench system as compared to the vertical well system. The recommended location of the leachate recirculation system is at about 30%–40% of the overall height of the landfill, measured from the top surface.