Study on Surrounding Rock Stability of Mining Roadway Under Irregular Coal Pillar of Close Distance Coal Seams

In view of the problems of poor integrity and support difficulties in mining roadway under the upper stratified irregular coal pillar, taking 20314 auxiliary roadway of a coal mine in Inner Mongolia as engineering background. According to the actual mining conditions of the coal seam, FLAC^3D software was used to simulate and study the change rule of vertical stress of roadway under irregular coal pillar after mining in upper and lower coal seam working face. The results show that the vertical stress concentration occurs in the area of triangular rock stratum left between the goafs after mining the upper and lower coal seams. The roadway under the remaining coal pillar is affected by both the lateral supporting pressure and the upper residual pillar supporting pressure. When the vertical stress is greater than the peak compressive strength of the coal body in the roadway, the roadway is damaged.