Examining the optimum panel pillar dimension in longwall mining considering stress distribution

Abstract Longwall mining method is widely used for underground coal production in the world. Additional stresses occur surrounding the longwall during underground mining. Stresses occurring surrounding the longwall are investigated by many researchers for years. How these stresses affect longwall production, gob, main gate, tailgate and main haulage road has been always an important issue. In this study, the effect of the safety pillar left at the end of the panel on the main haulage road is investigated. For this purpose, 6 models with different pillar distances are created and the stresses occurring in the main haulage road, tailgate and main gate at different pillar distances are examined. It has been demonstrated with numerical models that the optimum pillar distance according to these stress conditions does not damage the main haulage road, tailgate and main gate. In addition, the pillar distance of 10 m gives maximum coal recovery efficiency, and it has been shown by numerical models that the stresses occurring in the main haulage road, main gate and tailgate are not damaging to these galleries.