ABSTRACT
Several failure incidents have been reported on surface lignite and coal mines, indicating that slope stability is crucial for the sustainability and reclamation of these areas. An analytical model was recently presented in the literature, concerning the evaluation of lignite mines’ slope stability in the presence of a weak zone. The model is based on a bilinear failure mechanism, which is mostly controlled by a sub-horizontal sliding surface along a low strength zone. In the present work, a numerical approach for lignite mines’ stability is compared with that analytical model. Assumptions of each model are discussed, and identical geometries and geotechnical parameters are implemented. The authors conclude that the analytical model is susceptible to the assumptions regarding the hydraulic conditions, indicating that an appropriate estimation of the safety factor may not be feasible under certain circumstances. Overall, the rigorousness of FEM analyses over more simplified analytical models is highlighted.
