Assessment of Seismic Stability of Coal Mine Overburden Dump Slope Using Random Limit Equilibrium Method (RLEM) and Random Finite Element Method (RFEM)—A Comparative Study

Adequate knowledge of stability of coal mine overburden (OB) dump in earthquake-prone areas is required for proper functioning of the coal mines since unanticipated dump failures may result in the loss of lives and interruption in mining activities. Considering the heterogeneity of the OB dump materials, the spatial variability of the material parameters of coal mine OB dump slope needs to be considered for safe assessment of their stability under seismic forces. Random limit equilibrium method (RLEM) and random finite element method (RFEM), both facilitate in carrying out the probabilistic investigation considering two-dimensional spatial variability. The probabilistic approach in RLEM combines the two-dimensional random field theory with limit equilibrium method, whereas RFEM combines two-dimensional random field theory with finite element method. The current study aims to assess the comparative seismic performance considering a series of isotropic and anisotropic random fields. The pseudostatic analyses of RLEM are performed in the software Slide2 (Rocscience), whereas the software OptumG2 is adopted for RFEM analyses. Finally, outcomes obtained from seismic stability analysis of OB dump slope performed with RLEM are compared with the corresponding ones performed using RFEM.