软岩巷道二次支护时机数值模拟研究

Numerical Study on Secondary Support Time of Soft Rock Roadway

针对星村煤矿-1196辅助进风大巷具体地质条件,首先根据相邻软岩巷道支护经验确定采取一次让压支护和二次大刚度支护相结合的支护方式。然后利用FLAC^(3D)对巷道开挖后,不同时机采取的二次支护效果进行模拟,结果表明,巷道开挖并采取一次让压支护措施后,巷道位移变形速率先急剧增长,达到峰值后迅速降低,最后趋于平稳;确定二次支护最佳时机为一次让压支护措施后6 000步,即在巷道围岩变形速率缓慢降低阶段施加二次支护效果最好。

In view of the specific geological conditions of the Xingcun coal mine-1196 auxiliary air intake roadway,firstly according to the supporting experience of adjacent soft rock roadways,it is determined that a support method combining pressure support and secondary large stiffness support is adopted.Then using FLAC3D to simulate the effect of secondary support at different time after excavation.The results show that after the excavation of the roadway and the pressure support measures are taken,the displacement deformation rate of the roadway first increases sharply,rapidly decreases after reaching the peak,and finally becomes stable.The best time for determining the secondary support is 6 000 steps after the pressure support measures are taken,that is,the secondary support effect is best applied when the surrounding rock deformation rate is slowly reduced.