大理岩卸围压破坏全过程的声发射及分形特征

发布时间：2018-06-02 22:19

本文选题：岩石力学 + 声发射　；参考：《岩石力学与工程学报》2015年S1期

【摘要】：采用极点对称模态分解方法对大理岩卸围压破坏的声发射数据进行去噪处理,分析大理岩卸围压变形破坏全过程的声发射变化特征。加载初期声发射振铃较小且增长缓慢,扩容点后声发射振铃计数率迅速增加。声发射时频变化呈现波动特征,峰值强度前频率出现突增,临近峰值强度时频率明显降低。利用关联维数方法计算大理岩卸围压破坏过程的声发射分形维数,声发射分形维数呈现阶段性变化,先增大后减小,在应力达到峰值强度的80%附近出现陡增,破坏时分形维数又出现大幅降低。频率变化特征与分形维的变化规律具有对应关系,声发射信号频率突然上升且分形维数陡增可认为是岩石破坏前兆。
[Abstract]:The acoustic emission data of marble under confining pressure are de-noised by polar symmetric mode decomposition method, and the characteristics of acoustic emission variation in the whole process of deformation and failure of marble under confining pressure are analyzed. At the beginning of loading, the acoustic emission ringing is small and the growth is slow, and the counting rate of the sound emission ring increases rapidly after the expansion point. The time-frequency variation of acoustic emission is characterized by fluctuation, the frequency before peak intensity increases suddenly, and the frequency decreases obviously near peak intensity. The correlation dimension method is used to calculate the acoustic emission fractal dimension in the failure process of marble unloading confining pressure. The fractal dimension of acoustic emission presents a phase change, which increases at first and then decreases, and then increases sharply near 80% of the peak strength of the stress. The dimension of the damaged time division form is reduced by a large margin. The characteristic of frequency change has a corresponding relationship with the change of fractal dimension. The frequency of acoustic emission signal rises suddenly and the fractal dimension increases sharply which can be regarded as the precursor of rock failure.
【作者单位】：青岛理工大学理学院;青岛理工大学蓝色经济区工程建设与安全山东省协同创新中心;
【基金】：国家自然科学基金资助项目(41472270,41372298) 青岛市科技计划基础研究项目(12 1 4 4 (10) jch)
【分类号】：TU45

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