Stability of Surrounding Rock and Roadway Layout in Close Coal Seam Underlying Residual Coal Pillar

For the problem that it is hard to control the large deformation of roadway surrounding rock which underlies residual coal pillar of close coal seam in a coal mine, strength coefficient and stress influence laws of coal seam underlying coal pillar are studied by the numerical analysis method, and combined with the industrial test, the arrangement of roadway has been optimized. The results show that after the mining of overlying coal seam, the extremely low area of surrounding rock, like a pentagon and taking the residual coal pillar as the center, is formed, as well as an area like semicircle is formed. Therefore, to ensure the stability of surrounding rock, when the layout of roadway is designed under this conditions, these areas should be avoided.