Study of Strata Behaviour in Blasting Gallery Panel in Coal Mines

Abstract

In mining industry, the challenging task of a mining professional comprises of the extraction of maximum natural resources with utmost safety of the miners. ¡§Blasting Gallery¡¨ method is a unique technique of depillaring thick seams for higher recovery of coal. The present study has been aimed to examine thoroughly BG method operational systems in Indian geo-mining conditions such as: „« Study of roof convergence with respect to face advancement during different stages of extraction of coal in Blasting Gallery panels in SCCL mines. „« Simulation of field conditions in the numerical model generated using FLAC. „« Interpretation of strata behaviour through numerical modeling using FLAC. For this purpose, BG panel of GDK 10 incline, Singareni Collieries Company Limited (SCCL) was selected. This mine has a thick coal seam of 11m, at a depth of 350mtr. Convergence behaviour with respect to goaf edge distance (GED) was monitored with the help of high state-of-the-art equipment throughout the life of BG panel. The coal sample was collected from the mine and tested for determination of the rock mass parameters. The geotechnical conditions of the mine were simulated through Numerical Modelling by FLAC. The results obtained from the FLAC were compared to field data so that the validation would represent the system in totality. The different conclusions drawn from this work is enumerated as follows: „« The maximum rate of convergence and cum. convergence recorded in field was 4mm/day and 61mm respectively, measured at station C-5 in 68 Level. „« From the triaxial testing, the major principal stresses of 22, 32 and 41.5 MPa were obtained at confining stresses of 0, 2 and 3 MPa respectively. „« The results obtained from the RocLab software indicated the Cohesion, Friction Angle, UCS and Tensile Strength values to be 1.1MPa, 30.840, 1.314 MPa and 0.32MPa respectively. „« The model predicted maximum cumulative convergence to be 70mm while that observed in field is 61mm.