预制裂隙岩石单轴压缩声发射特征研究

Research on acoustic emission characteristics of prefabricated fissure rock under uniaxial compressio

  • 摘要: 为了研究预制裂隙岩石失稳破坏过程中声发射特征,对预制不同倾角裂隙岩石进行了单轴压缩声发射试验,分析了预制裂隙岩石变形破坏特征及声发射信号变化规律。结果表明:随着预制裂隙倾角的减小,岩石试件的抗压强度逐渐降低,达到峰值应力的时间逐渐缩短,破坏时的轴向应变逐渐减小,试件由拉伸劈裂破坏向剪切滑移破坏转变;随着预制裂隙倾角减小,试件首次出现声发射能量和振铃计数峰值的时间提前、所需加载的轴向应力减小;声发射累计振铃计数随加载时间的增加呈非线性上升趋势,且预制裂隙倾角越小,声发射累计振铃计数上升速率越快。

     

    Abstract: In order to research acoustic emission (AE) characteristics during instability and failure of prefabricated fissure rock, uniaxial compression AE test of prefabricated fissure rock with different inclination angles was carried out, and deformation and failure characteristics of prefabricated fissure rock and variation law of AE signals were analyzed. The results show that with the decrease of prefabricated fissure inclination angle, compressive strength of rock specimens gradually decreases, time to reach the peak stress gradually shortens, axial strain during rock failure gradually decreases, and specimen changes from tensile splitting failure to shear sliding failure. With the decrease of prefabricated fissure inclination angle, the time when the peak of AE energy and ringing count first appear in specimen is advanced and the axial stress required for loading decreases. The cumulative AE ringing count shows a nonlinear upward trend with the increase of loading time, and the smaller the prefabricated fissure inclination angle is, the faster the cumulative AE ringing count rises.

     

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