Selection and Optimization Mechanism of the Lower Return Roadway Layout in the near Residual Coal Pillar Area

Background: To optimize the layout position of residual coal pillar return roadway when mining a close seam group and to clarify optimization mechanism, analysis was conducted on Tashan mine. Methods: Surface displacement monitoring using field tests, main stress magnitude, plastic zone morphology, deformation variables, connectivity between were analyzed at different locations with help FLAC3D numerical simulation software. Results: It found that, in process mining, overlying seriously affects state distribution lower roadway. The is arranged that relatively far away from pillar, which could reduce influence guarantee stability Conclusion: Since Mine uses top release method for can be better ensured by placing middle regions retain small pillars.