基于声发射波形能量谱的岩石裂隙演化研究
Investigation on evolution of rock fractures based on acoustic emission by waveform energy spectrum
邓绪彪 1王新月 1孙本利 2敬晨辉1
作者信息
- 1. 华北水利水电大学 地球科学与工程学院,河南 郑州 450046
- 2. 长安大学 地质工程与测绘学院,陕西 西安 710054
- 折叠
摘要
通过白砂岩预制裂纹样的三维声发射监测试验,采用声发射波形的空间能量分布确定岩石裂隙扩展方向,研究了单轴压缩下白砂岩的裂隙演化特征;运用短时傅里叶变换(STFT)获取各通道波形的能量谱,以能量最小通道到能量最大通道的方向表示微裂隙方向,以能量大小表征裂隙长度,得到微裂隙声发射矢量.研究表明:白砂岩的裂隙扩展以平行于主应力方向和理论共轭剪切面方向为主,在初始压密段和弹性段,以某一方向裂隙为主导;从裂隙变形段开始,3 个方向上的裂隙占比开始逐渐趋同,在峰前软化段趋于30%;声发射矢量沿主破裂面集聚分布,且在峰前软化段形成贯穿岩样的剪切带,是较为可靠的岩石破坏临界前兆.
Abstract
Based on the three-dimensional acoustic emission monitoring test of white sandstone with prefabricated crack,the fracture propagation direction was determined by the spatial energy distribution of acoustic emission waveform,and the fracture evolution characteristics of white sandstone under uniaxial compression were studied.Short-time Fourier transform(STFT)was used to obtain the energy spectrum of each channel waveform,and the direction of microfracture was represented by the direction of the smallest energy channel to the largest energy channel.The energy intensity was used to represent the fracture length.The results show that the fracture propagation of white sandstone is mainly parallel to the principle stress direction and the theoretical conjugate shear plane direction.In the initial compaction section and elastic section,the fracture is dominated by a certain direction.Starting from the fracture deformation section,the fracture proportion in the three directions gradually converged,and tended to be 30%in the pre-peak softening section.It is also found that the AE vector is clustered along the main fracture surface.Shear zone running through the rock sample is formed in the pre-peak softening section,which is considered as a reliable critical precursor to rock failure.
关键词
声发射/波形能量谱/裂隙扩展方向/破坏前兆/剪切带Key words
acoustic emission/waveform energy spectrum/fracture propagation direction/failure precursor/shear zone引用本文复制引用
基金项目
国家自然科学基金(42277141)
国家重点研发计划项目(2019YFC1509704)
出版年
2024
NETL
NSTL
万方数据