Design of panel and support system for extraction of inclined thick coal seam using numerical modelling

The depillaring operation develops high stress concentration in the workings and poses many strata control issues such as roof convergence, floor heaving, side spalling and pillar/ribs crushing. A detailed stability analysis need to be conducted to control these strata issues and estimate the optimum coal panel size and support system. In this paper, the stability analysis of the panel and design of the support system are presented for safe winning of inclined coal seam using 2D and 3D numerical modelling approach. The panel is developed by rhombus pillars of 25 m × 25 m size with 4.2 m and 4.8 m wide galleries and being proposed for depillaring. 3D and 2D numerical models are used to analyse the development of stresses during depillaring operation and determine the working conditions respectively. This study suggests the suitable pillar size, gallery width, mining height and the required support resistance.