Analysis on the load of coal pillar above the working face and the effect of coal pillar blasting

Overlying residual coal pillars on the working face brings serous safety hazards to coal mine safety production, which is easy to cause coal rock dynamic disaster during the process of mining.This paper theoretically calculates the load of two coal pillars with different widths and different roof spans on both sides, and calculates the stress of the coal pillar load transferred to the corresponding coal pillar position in the underlying coal seam adopting the theory of elastic mechanics.The vertical stress distribution characteristics of the corresponding coal pillar positions in the working face before and after the blasting of the overlying coal pillars is simulated by using FLAC^3D numerical simulation technology; the average value of the support resistance of the hydraulic support during periodical pressurized and non-periodical pressurized is monitored by the mine pressure monitoring system.According to the results of numerical simulation and field measurement, the vertical stress of the corresponding coal pillar position in the working face is obviously reduced after the coal pillar blasting, and there is no coal rock dynamic phenomenon such as abnormal pressure during the mining process.Therefore, the coal pillar pre-splitting blasting technology can effectively control the coal and rock dynamic disasters induced by the overlying coal pillars, and ensure the safety mining of the working face.