五老峰隧道岩爆声发射参数特征研究

为研究岩爆事件的声发射特征，为岩爆灾害的进一步监测预警提供依据，对五老峰隧道掌子面附近区域岩爆事件进行声发射监测，以RA均值作为主要参数，研究岩爆发生前后的参数变化规律，并通过与b值等参数分析结果的相互印证，对比岩爆信号与爆破震动信号之间的区别。试验结果表明:不同传感器因为布设位置、耦合程度的差异，接收到的声发射信号数量与参数分布范围存在较大差异；RA均值作为参数分析依据，能够较好地反映岩爆事件的孕育发展过程，且能够一定程度上消除传感器接收信号数量差异的影响，更稳定地反映岩爆事件的信号特征；岩爆事件发生前RA均值与事件密度不断升高，峰值后则都迅速降低，而爆破产生的声发射信号则在RA值上存在一定突变性，且峰值后仍保持较高水平。本次监测中，共发生1次微型岩爆，而在左洞爆破后，声发射信号明显增多，但并未产生显著破裂事件。

Research on characteristics of AE parameters for rock burst in Wulaofeng tunnel

In order to study the acoustic emission (AE) characteristics of rock burst events,and provide the basis for the further monitoring and early warning of rock burst disaster,the AE monitoring on the rock burst events at the area near the tunnel face of Wulaofeng tunnel was conducted.Taking the RA average value as the main parameter,the change laws of parameters before and after the rock burst were studied,and the difference between the rock burst signals and the blasting vibration signals were compared through the mutual corroboration with the parameter analysis results such as b value.The results showed that the amount of accepted AE signals and the range of parameters distribution had great difference due to the different layout positions and coupling degrees of different sensors.As the parameter analysis basis,the RA average value could reflect the inoculation and development process of rock burst event well,and eliminate the influence of different amounts of signals accepted by the sensors to a certain extent,so as to reflect the signal characteristics of rock burst event more stably.The RA average value and events density increased continually before the rock burst event and both decreased rapidly after the peak,while the AE signals produced by the blasting had certain mutability on the RA value,and still kept higher level after the peak.In this monitoring,a miniature rock burst occurred,while after the left hole blasting,the AE signals increased obviously,but there was no significant break event.