Dhananjai Verma¹, Ashutosh Kainthola^1,, S S Gupte¹, T N Singh¹

Designing of a stable overburden disposal slope is vital in large opencast coal mines. Spoil generated during extraction of coal which is dumped externally requires larger land to remain stable and also poses problems to surrounding environment due to limited land availability. This has lead to the preference of internal dumping in which the waste is dumped in de-coaled region which is beneficial during extraction and reclamation of mine. Internal dumping is also the most economical and environment friendly method of waste disposal and is being adopted everywhere. It has certain limitations and inherent dangers of failures posing operational and safety threats. In this paper, a numerical study for stability of 80 m high internal dump slopes from an opencast coal mine of Wardha Valley Coal Field, Maharashtra, India has been carried out using Finite Element Method (FEM). Different scenarios as per the dump heights have been accounted and simulated using Plaxis2D-8 to understand the failure mechanism and the changes in factor of safety with variation in bench height and the number of benches.

internal dump, slope stability, numerical modeling, Coal Field