Performance of Coal Mine Overburden Dump Slope Under Earthquakes Using Extended Finite Element Method Based Voronoi Tessellation Scheme

The occurrence of earthquakes in coal mining areas endangers the stability of the overburden (OB) dumps. This leads to the damage of mining properties, disturbance in mining activities and loss of lives. Ultimately, the production time of the desired amount of coal gets delayed. Owing to the heterogeneous nature of the OB dump, the proper determination of its material properties becomes difficult. In the present work, the opencast coal mine in Jambad, India has been considered to be the study area. Thus, the properties of materials based on multi-channel analysis of surface waves (MASW) investigation have been used in the numerical analyses. The size and shape heterogeneity of the OB dump particles was represented by means of the extended finite element method (XFEM) based Voronoi tessellation scheme using the two-dimensional geotechnical software RS2. In order to consider a wide range of strong ground motion parameters, a set of ten earthquakes were selected for performing the dynamic analyses of a double-benched OB dump. The influence of peak ground acceleration (PGA) on the amplification ratio at various key points of the OB dump was estimated and compared taking into account the heterogeneous and homogeneous OB dumps. The guidelines prepared for the coal mine OB dumps are entirely silent on the effect of earthquakes, therefore this study would be useful in framing of the guidelines considering the influence of earthquakes on the coal mine OB dump slopes.