Numerical Modelling of Coal Mine Overburden Dump Slopes: Developments and Current State-of-the-Art

Abstract

AbstractWith the rapid increase in the accumulation rate of coal mine overburden (OB) dumps, the geoenvironmental hazards due to their failures have taken a toll. A major segment of the standard Indian regulations laid down for the overall geometry of the OB dump is based on limit equilibrium method (LEM) without any information about the displacement of the failed slope, confining stresses, stress–strain behaviour of slope material, time factor and heterogeneity (shape and size). This paper highlights the various methodologies used in the stability analysis of coal mine OB dumps. The problem domain in continuum approaches is considered as a single continuous body, so they are unable to model the discrete particle failure in the OB dump mass, whereas in the discontinuum approaches (like discrete element method (DEM)) it is treated as an assembly of independent particles giving a better realistic representation. Using DEM, the studies on slope stability analysis of OB dumps considering the aspects of heterogeneity of particles, site and environmental factors are very limited. Though OB dump consists of heterogeneous material, the previous literature is silent on the aspect of reliability analysis. The work presented here sheds light on all the above aspects from past literature and is believed to serve as a significant contribution in knowing the shortcomings, challenges and moving towards the feasible solutions utilizing the most appropriate computational technique.KeywordsCoal mine overburdenContinuumDiscontinuumDiscrete element methodNumerical modellingSlope stability analysis