Abstract:
This study takes the mining of B
1+2 and B
3-6 coal seams in the southern mining area of a steep and thick coal seam mine as the engineering background, and combines theoretical analysis and numerical simulation methods to compare and study the effects of horizontal and inclined segmented mining of steep and thick coal seams on the prevention and control of rock burst. The results show that: before mining the B
3-6 seam at the same level, the stress concentration area of horizontal sectional mining is mainly located in the surrounding rock above and below the roadway and the coal body below the gob, while the stress concentration area of inclined sectional mining is shifted to the coal body at the sharp corner area below the gob and the surrounding rock above and below the roadway at the low level side; compared with horizontal sectional mining, the peak stress in the surrounding rock above and below the high level side roadway of inclined sectional mining is reduced by 10-20 MPa, and the stress concentration roadway is reduced from 4 to 2; mining the B
3-6 coal seam first at the same level can weaken the horizontal stress transfer, and it has the function of pressure relief protection for the B
1+2 coal seam mined later. In addition, under the condition of inclined sectional mining, the inclined gob can further weaken the horizontal stress transfer, and it has the function of pressure relief protection for the high level side roadway; based on comprehensive comparison, it is believed that the stress level of the surrounding rock above and below the roadway is lower and the degree of deformation of the roadway is the lowest, which is more conducive to the prevention and control of rock burst.