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声发射是岩石变形破裂过程中的重要物理现象,也是反映岩石力学特性的一个本构参量。通过三轴应力条件下大尺度岩石损伤破坏声发射试验,得到了3类岩石破坏全过程力学特征和声发射特征。试验中利用高速多通道声发射数字记录系统,获得了岩石试件破坏前微破裂活动的详细时空分布数据。基于试验结果,研究了3类岩石(花岗岩、砂岩、大理岩)压缩变形破坏及其能量演化特征,进而推导出声发射累积能量释放与载荷之间的关系,并研究了预测岩石宏观破坏的前兆现象——能量加速释放。结果显示,3类岩石试件宏观破坏前均出现了能量加速释放现象,同时花岗岩的声发射次数发展都大于砂岩和大理岩,花岗岩与砂岩的损伤都以微破裂为主。
Acoustic emission is an important physical phenomenon in the process of rock deformation and rupture. It is also a constitutive parameter that reflects rock mechanical properties. Through the acoustic emission test of large-scale rock damage under triaxial stress, the mechanical characteristics and acoustic emission characteristics of the three types of rocks during the whole process of failure are obtained. In the experiment, the high-speed multi-channel acoustic emission digital recording system was used to obtain the detailed spatiotemporal distribution data of the micro-fracture activity of the rock specimen before it ruptured. Based on the experimental results, the compression deformation and failure of three types of rocks (granite, sandstone and marble) and their energy evolution characteristics are studied. Then the relationship between the cumulative energy release of acoustic emission and the load is deduced and the precursory prediction of macroscopic failure of rock is studied Phenomenon - Accelerated release of energy. The results show that the accelerated release of energy occurs before the macroscopic failure of the three types of rock specimens. At the same time, the number of acoustic emission of granite develops more than that of sandstone and marble, while the damage of granite and sandstone are dominated by micro-cracks.