单轴压缩下粗砂岩临界破坏的多频段声发射耦合判据和前兆识别特征
发布时间：2018-09-07 06:50
【摘要】：为寻求岩石临界破坏判据和前兆特征,在粗砂岩单轴压缩声发射(AE)试验的基础上,研究了岩石破坏过程中AE信号频段占比随应力变化特征,重点分析高、低两个特征频段占比随应力变化规律,同时对两个特征频段中不同应力水平下AE幅值关联维数进行计算与分析,并建立了基于频段占比与应力间关系的多频段AE信号主频识别判据模型。研究表明:AE信号频段占比的分布特征能较好地诠释岩石破坏所经历的主要过程;岩石破坏过程中,较低频段AE信号(31.25~46.875 k Hz)占比先减小后增大,较高频段AE信号(140.625~156.25 k Hz)占比先增大后减小。在临界破坏状态下,高、低两个特征频段占比分别出现最大值和最小值,且二者中AE幅值关联维数都下降到最低。通过对特征频段占比与应力之间的耦合分析,利用特征频段占比、AE幅值关联维数的变化可更准确地对岩石临界破坏前兆进行判别和预测。
[Abstract]:In order to find out the critical failure criterion and precursor characteristics of rock, on the basis of uniaxial compression acoustic emission (AE) test of coarse sandstone, the variation of frequency ratio of AE signal with stress during rock failure is studied, with emphasis on the analysis of high frequency. At the same time, the correlation dimension of AE amplitude under different stress levels in the two characteristic bands is calculated and analyzed. The main frequency identification criterion model of multi-frequency AE signal is established based on the relationship between frequency band duty cycle and stress. The results show that the distribution characteristics of the proportion in the frequency band of the 1: AE signal can better explain the main process of rock failure, and during the rock failure, the AE signal of the lower frequency band (31.25% 46.875 k Hz) decreases first and then increases. The AE signal (140.625 k Hz) / 156.25 k Hz) in the higher frequency band firstly increased and then decreased. In the critical failure state, the maximum and the minimum ratio of the high and low characteristic frequency bands appear respectively, and the correlation dimension of the AE amplitude decreases to the lowest. By analyzing the coupling between the ratio of the characteristic frequency band and the stress, the variation of the correlation dimension of AE amplitude in the characteristic frequency band can be used to judge and predict the rock critical failure precursor more accurately.
【作者单位】： 北京科技大学土木与资源工程学院;内蒙古伊泰广联煤化有限责任公司;中冶建筑研究总院有限公司;
【基金】：国家重点研发计划项目(2016YFC0600801) 国家自然科学基金重点项目(51534002);国家自然科学基金项目(51174015)
【分类号】：TU45
本文编号：2227512
[Abstract]:In order to find out the critical failure criterion and precursor characteristics of rock, on the basis of uniaxial compression acoustic emission (AE) test of coarse sandstone, the variation of frequency ratio of AE signal with stress during rock failure is studied, with emphasis on the analysis of high frequency. At the same time, the correlation dimension of AE amplitude under different stress levels in the two characteristic bands is calculated and analyzed. The main frequency identification criterion model of multi-frequency AE signal is established based on the relationship between frequency band duty cycle and stress. The results show that the distribution characteristics of the proportion in the frequency band of the 1: AE signal can better explain the main process of rock failure, and during the rock failure, the AE signal of the lower frequency band (31.25% 46.875 k Hz) decreases first and then increases. The AE signal (140.625 k Hz) / 156.25 k Hz) in the higher frequency band firstly increased and then decreased. In the critical failure state, the maximum and the minimum ratio of the high and low characteristic frequency bands appear respectively, and the correlation dimension of the AE amplitude decreases to the lowest. By analyzing the coupling between the ratio of the characteristic frequency band and the stress, the variation of the correlation dimension of AE amplitude in the characteristic frequency band can be used to judge and predict the rock critical failure precursor more accurately.
【作者单位】： 北京科技大学土木与资源工程学院;内蒙古伊泰广联煤化有限责任公司;中冶建筑研究总院有限公司;
【基金】：国家重点研发计划项目(2016YFC0600801) 国家自然科学基金重点项目(51534002);国家自然科学基金项目(51174015)
【分类号】：TU45
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