Study Of Stress Distribution And Stress Control In Blasting Gallery Method Working

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. This task becomes more problematic when the thickness of coal seam is larger. “Blasting Gallery” method is a unique technique of depillaring thick seams for higher recovery of coal. The extensive literature survey clearly helps to understand that the ultimate potentiality of the method is yet to be explored. Though a number of researchers, academicians and other stake holders attempted to work on it but impact of many significant parameters are still to be analyzed. The Blasting Gallery operation in a mechanized underground mine system depends upon many decisions influenced by the geo-technical parameters which are often interspersed with inherent strata configurations. The present study has been aimed to examine thoroughly BG method operational systems in Indian geo-mining conditions such as: Ø Study of roof convergence with respect to face advancement during different stages of extraction of coal in Blasting Gallery panels in SCCL mines. Ø Simulation of field conditions in the numerical model generated using FLAC. Ø Interpretation of strata behaviour through numerical modeling using FLAC. In order to study the strata behaviour of such coal mines with thick seams, GDK 10 incline, 3A panel of Singareni Collieries Company Limited (SCCL), Ramagundam was selected. This mine has a thick coal seam of 11m and is at depth of 350mtr, practicing Blasting Gallery method to the maximum extent. Convergence behaviour with respect to goaf edge distance (GED) was monitored with the help of high state-of-the-art equipment (calibrated) throughout the life of BG panel. An over emphasis was given on the field study where data of BG mine specially related to natural falls, induce blasting etc. were recorded. Convergence of roof strata in mm, corresponding goaf edge distance (GED) in meter (m), corresponding distance from face in meter (m) and depth of panel in meter (m) were measured to know the significant impact of different layers with varying overburden pressure which leads us to think some logical sequence of interrelated operations.