花岗岩巷道岩爆声发射信号及破裂特征实验研究

Experimental study on rockburst acoustic emission signal and fracture characteristics in granite roadway

  • 摘要: 以声发射能量、振铃计数、上升时间和主频作为特征参数,对巷道岩爆实验声发射信号进行聚类分析,得到3类声发射信号。深入分析3类声发射信号特征参数,挖掘其对应的物理意义,揭示其反映的破裂特征。基于能量释放率,确定驱动岩爆灾害形成的主要岩石破裂类型。利用该类破裂对应的声发射信号,进行巷道岩爆预测研究。研究结果表明:第1类信号具有高能量、高振铃计数、低上升时间和低主频的“两高两低”特征,对应高强度、大尺度裂纹稳定扩展;第2类信号具有高能量、高振铃计数、高上升时间和低主频的“三高一低”特征,对应高强度、大尺度的裂纹非稳定扩展;第3类信号具有低能量、低振铃计数、低上升时间和低主频的“四低”特征,对应低强度、小尺度的裂纹非稳定扩展。其中,高强度、大尺度的裂纹非稳定扩展是岩爆灾害形成的主要驱动力,该种破裂类型对应的“三高一低”特征信号,能够为岩爆提供早期预警信息,是岩爆灾害预警研究的重点关注对象。

     

    Abstract: Three kinds of AE signals were obtained through clustering and analyzing the acoustic emission signals of rock burst experiments and the characteristic parameters including AE energy,ringing count,rise time and frequency. By analyzing the characteristic parameters of three kinds of AE signals deeply,excavating their corresponding physical meanings,the fracture characteristics were revealed. Based on the rate of energy release,the main types of rock failure formed by driving rock burst were determined. Use the corresponding AE signals,the rock burst was predicted. The re- sults show that the first kind of signals has high energy,high counts,low rise time and low frequency features,and the “two highs and two low” feature corresponds to the stable expansion of crack with high strength and large scale. The second kind of signals has high energy,high counts,high rise time and low frequency features,and the “ three highs and one low” feature corresponds to the unstable expansion of crack with high strength and large scale. The third kind of signals has low energy,low ringing count,low rise time and low frequency features,and the “four low” feature corresponds to the unstable expansion of crack with low strength and small scale. Among them,the unstable expansion of crack with high strength and large scale is the main driving force of rock burst. The “three highs and one low” feature can provide early warning information for rock burst. It is the key target of early warning research of rock burst disas- ter.

     

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