Numerical simulation on the failure process of coal pillars in longwall remaining coal pillars support mining

To further optimize mining methods and parameters in water-preserved mining region in Shanbei mining area,the paper has made numerical simulation of failure process of coal pillar under two kinds of mining method including taking remaining 7 leaving the region coal pillars and taking 12 remaining 8 leaving strip coal pillars in Yubojie coal mine.Simulation showed that the stability of strip coal pillars is better than the region coal pillars at the same advancing distance.The method can provide a useful reference to mining method and mining parameter optimization for other coal mines with same geological condition.