Stress distribution influence on segment coal pillar at different dip angles of working face

Abstract：In accordance with specific conditions of coal seam Ⅱ1 in No. 13 coal mine of Pingdingshan Coal Mine Group, on the buried depth of coal seam 300,500,800 m and dip angles of 0,25°,30°, side abutment pressure distri- bution rule of haulage roadway and the different width of coal pillar stress condition were analyzed by numerical simu- lation, through the site monitoring for the entity coal side stress under the lane, surrounding rock deformation and an- chor stress situation at the mine working face 12020. The results show that with the angle of coal seam increased, both sides stress of lower section haulage roadway and upper section return airway present asymmetric distribution, stress distribution of stope roof is also uneven and asymmetrically high, the peak of lateral horizontal stress grows with the in- creasing angle of coal seam, and increasing extent behind working face is larger than ahead of the working face, peak position gradually approaches coal wall with the angle of coal seam increase. When the angle of coal seam increase, the stress obviously tends to lower section haulage roadway arid the top of this position will appear significantly stress con- centration problems, moreover, the difference has a larger trend with the angle of coal seam increase. The numerical analysis results are the same as the field sampling parameters and it is of great importance to the optimization of sec- tion pillar and roadway safe support.