基于声发射技术的隧道岩爆倾向性判别

Discrimination of Rock Burst Tendency of Tunnel Based on Acoustic Emission Technology

为了更加形象地表述岩爆倾向性的判别方法,减少经验判断,在室内岩石力学实验基础上引入声发射监测方法,并提出通过声发射特征参数的时序演化来描述及判别岩石的岩爆倾向性,即根据实验过程中声发射振铃累计计数的时序演化特点,将不同岩爆倾向性的岩石划分为3种释放形式,即线性增长型、阶梯增长型和指数增长型,并分别对应无/弱岩爆倾向性、中等岩爆倾向性以及强烈岩爆倾向性.最后,以取自铜绿山隧道岩芯的玢岩为试验对象开展实验.结果显示:编号P-1与P-3两试件的声发射振铃累计计数时序演化特征表现出明显的指数增长形式,说明这两个试件均具有强烈岩爆倾向性,试验结果同常规岩爆倾向性的判别相符,据此可进一步推广于实践检验.

In order to make the rockburst tendency judgment method more vivid and reduce the empirical judgment,the acoustic emission monitoring method is introduced on the basis of the laboratory rock mechanics experiments,and the time series evolution of acoustic emission characteristic parameters is proposed to describe and distinguish the rock burst tendency.According to the time series evolution characteristics of cumulative count of acoustic emission ringing during the experiment,the rocks with different rock burst tendencies are divided into three kinds of releasing forms:linear growth type,step growth type and exponential growth type,corresponding to no/weak rockburst tendency,medium rockburst tendency and strong rockburst tendency,respectively.Finally,the porphyrite taken from the core of Tonglvshan tunnel is used as the test object to carry out the experiment.The experimental results show that the time series evolution characteristics of cumulative count of acoustic emission ringing of sample numbered P-1 and P-3 show an obvious exponential growth form,indicating that both specimens have a strong rockburst tendency.The test results are consistent with the conventional rockburst tendency discrimination,which can be further extended to the practical tests.