基于GPR的巷道围岩空区探测及支护设计

GPR Based Detection and Support Design of Goaf in Roadway Surrounding Rock

为确保地下矿山掘进巷道围岩稳定性,发现前方不良地质体,采用地质雷达对掘进巷道围岩及底板进行空区探测,并对巷道围岩进行不同地应力作用下的稳定性分析,对不同长度锚杆加固后的锚杆轴力进行对比。结果表明:雷达探测的两个区域均出现不同深度的振幅较强反射区;1.5 m锚杆支护作用下围岩最大位移量分别减少39.3%和10.0%,X-有效应力分别增加42.8%和37.5%;1.5 m和1.8 m锚杆支护时轴力变化基本相同。根据同相轴的连续性对异常区进行判断,异常信号为充填不密实区及空洞,采用锚杆锚网喷浆支护。研究成果可以为类似矿山巷道围岩稳定性及支护提供借鉴意义。

In order to ensure the stability of the surrounding rock of underground mining excavation tunnels and identify unfavorable geological bodies ahead,geological radar was used to detect the empty area of the surrounding rock and floor of the excavation tunnel,and stability analysis was conducted on the surrounding rock of the tunnel under different geostress effects.The axial force of anchor rods with different lengths of reinforcement was compared.The results indicate that both areas detect by the radar exhibit strong amplitude reflection zones at different depths.Under the action of 1.5 m anchor rod support,the maximum displacement of the surrounding rock decreases by 39.3%and 10.0%respectively,and the X-effective stress increases by 42.8%and 37.5%respectively.The axial force changes are basically the same when supported by 1.5 m and 1.8 m anchor rods.Based on the continuity of the same phase axis,the abnormal area is judged,and the abnormal signal is the unfilled area and cavity,which are supported by anchor bolts,anchor mesh,and shotcrete.The research results can provide reference significance for the stability and support of surrounding rocks in similar mine tunnels.