基于矩张量理论的岩石破裂声发射震源机制分析

发布时间：2018-07-12 12:39

本文选题：矩张量 + 岩石破裂　；参考：《东北大学》2013年硕士论文

【摘要】：岩石是典型的具有非均匀性的脆性材料,内部富含各种缺陷(微裂纹、孔隙、节理裂隙等)。岩体变形破坏过程的实质是岩石中裂纹的萌生、扩展、相互作用和贯通的过程。开展岩石声发射试验研究,观测岩石内部微裂纹时空演化规律,对于岩石失稳破坏机制的研究、矿山地压灾害的预测预报具有十分重要的意义。对于岩石破坏机制的研究,仅仅知道微裂纹的时空分布特征是远远不够的,如果从本质上研究裂纹的演化机制,还需要知道裂纹的产生类型和滑移方向及其时空演化规律,这样才能更深层次的了解微裂纹之间的相互作用和扩展、贯通机制,而矩张量理论可以为这方面的研究提供一种有效的手段。论文主要针对以上提出的问题展开,研究内容如下： (1)采用自回归模型理论和AIC判据实现了声发射信号到时的提取,合理布置传感器阵列以满足声发射定位精度的要求；基于CAD二次开发实现了声发射事件定位、震源参数的直观显示。 (2)总结震源机制的研究方法,着重研究了既能得到岩石破裂宏观破裂类型结果,又能够得到岩石破裂面法线及运动方向的矩张量方法。基于弹性波动理论和矩张量理论,通过声发射信号P波初动振幅的拾取,对声发射定位事件的震源机制进行研究,进而得到岩石内部微裂纹的破裂方向、大小、滑移方向等参数,同时给出了基于声发射数据的矩张量求解流程,并采用Matlab软件编写了相关数据分析程序。 (3)开展了三点弯曲和“Z”型剪切实验,通过对比分析微裂纹的破裂类型结果与试样的最终破坏形式,验证了自行编写的矩张量分析程序对岩石裂纹产生、扩展机制研究的可靠性。 (4)采用圆形孔、拱形孔和双方孔岩石单轴加载试验,对岩石的破坏机制进行研究。在矩张量分析的基础上,结合声发射定位和震源机制,研究了微裂纹萌生、扩展、群集直至岩石失稳破坏的演化过程；分析了不同类型微裂纹的数量、群集程度、滑移方向等参数对最终破裂面形成和岩石失稳破坏的贡献值；研究了微裂纹之间的相互作用机制与宏观裂纹贯通过程之间的内在关系。
[Abstract]:Rock is a typical brittle material with inhomogeneity, and its interior is rich in various defects (microcracks, pores, joints, fissures, etc.). The essence of rock mass deformation and failure is the initiation, propagation, interaction and penetration of cracks in rock. It is of great significance for the study of rock instability failure mechanism and the prediction of ground pressure disaster to carry out the rock acoustic emission test and observe the temporal and spatial evolution law of microcracks in rock. For the study of rock failure mechanism, it is far from enough to know the temporal and spatial distribution characteristics of microcracks. If we study the evolution mechanism of cracks in essence, we also need to know the generation type and slip direction of cracks and their space-time evolution law. In this way, the interaction and propagation of microcracks can be further understood, and the mechanism can be connected. The moment Zhang Liang theory can provide an effective means for the research in this field. The research contents are as follows: (1) the acoustic emission signal time extraction is realized by using the autoregressive model theory and the AIC criterion. The sensor array is arranged reasonably to meet the requirements of acoustic emission positioning accuracy. Based on the second development of CAD, the location of acoustic emission events and the visual display of source parameters are realized. (2) the research methods of focal mechanism are summarized. The moment Zhang Liang method, which can not only obtain the macroscopic fracture type of rock fracture, but also obtain the normal line and movement direction of rock fracture surface, is studied emphatically. Based on elastic wave theory and moment Zhang Liang theory, the focal mechanism of acoustic emission localization events is studied by picking up the initial amplitude of acoustic emission signal P wave, and then the direction and size of microcracks in rock are obtained. At the same time, the flow of moment Zhang Liang solution based on acoustic emission data is given, and the relevant data analysis program is compiled by Matlab software. (3) Three-point bending and "Z" shear experiments are carried out. By comparing and analyzing the fracture type results of microcracks and the ultimate failure form of the specimen, the reliability of the moment Zhang Liang analysis program written by ourselves for the study of crack generation and propagation mechanism of rock is verified. (4) Circular holes are used. The failure mechanism of arched hole and double hole rock under uniaxial loading was studied. On the basis of moment Zhang Liang analysis, combined with acoustic emission localization and focal mechanism, the evolution process of microcrack initiation, propagation, cluster up to rock instability and failure is studied, and the number and degree of different types of microcracks are analyzed. The contribution of slip direction and other parameters to the formation of ultimate fracture surface and the failure of rock instability is studied, and the internal relationship between the interaction mechanism between microcracks and the macroscopic crack transfixion process is studied.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU45

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