A comprehensive approach for evaluating stability of landfill cover

Landfill cover is one of the most important elements of any modern landfill, the integrity and stability of which is obviously a major issue in the design and construction of landfills. Tapered landfill cover is an attractive technique to enhance the stability of landfill cover. In most of design analyses of landfill cover, the simultaneous effects of reinforcement (root and artificial layer), seepage, and seismic forces are ignored, and only the impact of each of these forces on the landfill cover stability has incompletely investigated. Basically, simply neglecting the simultaneous effects of mentioned forces can lead to an overestimated factor of safety (FoS). A novel approach based on limit equilibrium method (LEM) was proposed to analyze the stability of tapered landfill cover, which is supported by artificial reinforcement layer in addition to the root system under seismic and seepage loading conditions. The results indicated that the reinforcement parameters (Kc/Kt and tR) remarkably affected the stability of tapered landfill cover system, specifically when the landfill cover is under extremely adverse conditions, and the slopes should remain steep and uninterrupted along their length to ensure optimal use of the landfill area; the application of proposed reinforcement mechanisms can significantly enhance the stability.