Study on rational stop driving distance between face to face roadway driving faces in outburst coal seam

In order to avoid dynamic disaster caused by stress superposition in front of face to face roadway driving faces in outburst coal seam,a mining stress influe nce zone in front of face to face roadway driving faces in Yonghong Mine was measured and simulated. The site measured results showed that the scope of mining influenc e zone in front of face to face roadway driving face in Yonghong Mine was 5 ~ 7 m,the scope of mining influence zone behind driving faces was 8 ~ 9 m and the scope of mi ning influence zone caused by single roadway driving was 13 ~ 16 m. The numerical simulation results showed that when working space between face to face roadway driv ing faces was 20 m,the moving support pressures between the driving faces would be superposed. When a distance between face to face driving roadway faces was37.5 m and 50 m,the coal pillars in the front of face to face driving faces would be in elastic status,the moving support stresses of the coal pillars in the front of driving faces would not have a superposition phenomenon occurred,but when the distance between the driving faces was37.5 m,the width of coal pillar would be 12.5 m less than the width of coal pillar when the distance between the drving faces was 50 m. In combination with site measured,numerical simulation results and actual results in Yonghong Mine,the r ational stop driving distance between face to face driving faces was 50 m. At this moment,driving faces were not in the concentrated stress influence scope of the opposite side,there was a 12.5 m in-situ rock stress zone between driving faces and could ensure safety driving operation of the two faces.