采动条件下双巷掘进煤柱留设宽度数值模拟与优化研究OA

Aiming at the problem of reasonable coal pillar retention for doubleroadway tunneling at the 12108 working face of Lijiahao Coal Mine,a numerical simulation and optimization study on coal pillar width under mining conditions was carried out.The results show that the theoretical calculation indicates that the coal pillar width for roadway protection in doubleroadway tunneling should be greater than 9.41 m.According to FLAC3D numerical simulation,under primary mining,the plastic failure zone of the coal pillar between the two roadways corresponds to the vertical stress distribution.When a stress reduction zone with a"doublehump"shape appears,the plastic zone gradually changes from a through region to a nonthrough region,and the failure of the coal wall is weakened.For the 12109 air return roadway,the vertical stress on the coal pillar side changes from a single peak to double peaks with an increase in coal pillar width,and the peak value first increases and then decreases.Under secondary mining,the abutment pressure on the coal pillar side of the 12109 air return roadway shows no obvious change in stress peak with increasing coal pillar width,and the position where the peak is reached changes little,but the stress still evolves from a single peak to double peaks.Combining theoretical analysis and numerical simulation results,the reasonable coal pillar width under such conditions is determined to be 10 m.After adopting bolt(cable)support,the deformation of the mining-affected roof is significantly reduced,and the surrounding rock deformation is effectively controlled,meeting the requirements for safe production.