基于声发射的各向异性页岩变形破坏特征研究

Study on Deformation and Failure characteristics of Anisotropic Shale based on Acoustic Emission

为进一步研究各向异性页岩变形破坏特征,选取典型地区露头页岩,沿页岩自身层理面在不同方向取芯,进行基于声发射的单轴压缩试验。研究表明抗压强度随层理角度的不同具有显著的各向异性;单轴压缩时层理角度越大对破坏形式影响越大,破坏面沿层理面发育越明显;不同层理角度页岩试样的轴向应力值和破坏的各个阶段与声发射振铃计数和累计能量之间存在良好的相关性;通过声发射参数中的上升时间和幅值的比值(RA)、振铃计数和持续时间的比值(AF)值所判断的页岩单轴压缩破坏形式和试样宏观破坏形态基本一致。

In order to further study the deformation and failure characteristics of anisotropic shale,the outcropping shale in typical areas was selected and cored in different directions along its own bedding surface to conduct uniaxial compression test based on acoustic emission.The results show that the compressive strength has significant anisotropy with different bedding Angle;In uniaxial compression test,the larger the Angle of the bedding,the greater the influence on the failure form,and the more obvious the failure surface develops along the bedding surface;The axial stress and failure stages of shale samples with different bedding angles have good correlation with acoustic emission ringing count and accumulated energy;According to the RA and AF values in acoustic emission parameters,the failure form of shale uniaxial compression is basically the same as the macroscopic failure form of the sample.