不同传感器安装方式对隧道现场声发射参数监测结果的影响

为研究不同传感器安装方式对隧道现场声发射监测结果的影响,以渝广高速华蓥山隧道掘进爆破中的声发射响应试验为依托,通过隧道现场试验的方法对比了原岩表面安装、初衬表面安装、锚杆端部安装等3种声发射传感器安装方式下的声发射参数监测结果。从参数分析结果来看,不同的传感器安装与耦合方式对声发射监测结果有较大的影响,尤其是锚杆端部安装方法的声发射参数监测结果与前两者差异较大,这种差异主要源于波传播过程中穿过的交界面数量及介质截面积变化等,因此在现场监测过程中应当重点关注监测点附近的结构特征,选择合理安装方式,或充分利用监测点附近结构对信号的放大效应,削弱衰减与环境噪声的影响。

Influence of the Attaching Methods of Sensors on In-Situ Monitoring Results of AE Parameters in Tunnels

In order to study the influence of the attaching methods of sensors on AE monitoring results of in-situ AE monitoring in tunnels, parameters were analyzed and compared while the AE sensors were attached on the rock, initial lining and tip of the bolts, based on the experiments of AE monitoring during excavation blasting of Huayingshan Tunnel, Yuguang Expressway. The results show that different attaching methods or coupling modes indeed influence the AE monitoring results, especially the method of attaching on the tip of the bolts, whose results are in significantly difference to that of other methods. The differences are mainly come from the interfaces amount or cross-sectional area change of the media during the propagation process of the stress wave. It is concluded that during the in-situ AE monitoring process, it is necessary to consider the structural characteristics near the monitoring point to choose an appropriate sensor attaching method or make full use of the amplifying effect of the structure near the monitoring point to reduce the influence of attenuation and environmental noise.