Study on Comparison and Analysis on Pressure Releasing Effect of Boreholes in Soft and Hard Seam

In order to analyze a issue of the borehole pressure releasing effect in the soft seam better than the borehole pressure releasing effect in the hard seam of the mine with mine pressure bumping, the finite element numerical simulation software FLAC was applied to the analysis and study on the large diameter borehole pr essure releasing effects in soft seam and hard seam.The results showed that when the borehole depth reached at 1015 m, the inner stress of the soft seam would be 35 MPa and the inner of the hard seam would be 29 MPa.The 35 MPa stress scope of the soft seam would be higher than the 29 MPa stress of the hard seam.Therefore th e borehole pressure releasing effect conducted in the soft seam would be good and the borehole pressure releasing effect conducted in the hard seam would be poor.T he large diameter borehole pressure releasing operation was conducted in No.7123 coal mining face of Zhangshuanglou Mine and the pressure releasing effect was the same to the numerical simulation results.