软岩巷道底板卸压槽合理深度的模拟研究

Simulation Study on Reasonable Depth of Pressure Relief Groove in Soft Rock Roadway Floor

随着开采深度的增加,深部软岩巷道的地应力变大,软岩巷道围岩出现显著变形,围岩破碎、底鼓也越来越严重,对巷道围岩稳定性的控制变得极其困难[1]。底板中部开挖卸压槽,使巷道周边形成的应力峰值向远离巷道周边的围岩深部转移,使巷道处于应力降低区中,达到有效维护巷道的目的,但是卸压槽的深度会影响巷道的维护质量,太浅影响卸压效果,太深则不容易施工。利用FLAC3D数值模拟软件[2],模拟不同深度的卸压槽,观测巷道围岩的应力和位移变化,分析对巷道底鼓和围岩的影响。

With the increase of mining depth, the stress of deep soft rock roadway is higher than before, the soft rock of roadway is significantly deformed, destruction of surrounding rock and heaving floor become more and more serious, the control of the stability of surrounding rock in roadway has become extremely difficult. Pressure relief groove is excavated in the middle of floor, the peak stress of surrounding rock around roadway transfers to the deep far away, as a result that the roadway lies in the stress decreasing zone so that the roadway can be effectively maintained. However, the pressure relief groove depth may influence the roadway maintenance quality. If the depth is too shallow, the pressure relief is not good enough. If too deep, the cost is high. By using the FLAG3D simulation software, the pressure relief groove of different depths can be simulated. By observing the change of stress and displacement of surrounding rock roadway, the effect on surrounding rock and bottom bulge is analyzed.