Fractal property of spatial distribution of acoustic emissions during the failure process of bedded rock salt
Fractal property of spatial distribution of acoustic emissions during the failure process of bedded rock salt
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DOI：
10.1016/j.ijrmms.2011.09.014
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发表时间：
2011-12
影响因子：
7.2
通讯作者：
Heping Xie;Junyong Liu;Y. Ju;Jing Li;Lingzhi Xie
中科院分区：
文献类型：
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作者：
Heping Xie;Junyong Liu;Y. Ju;Jing Li;Lingzhi Xie
采用岩石力学试验系统和声发射试验系统对层状岩盐试样进行了单轴压缩和间接拉伸试验。基于分形几何的基本理论，提出了一种柱覆盖法来分析岩石损伤破坏过程中声发射空间分布的分形特性。实验结果表明，由于层状岩盐的结构差异，试样不同部位的破坏特征存在明显差异。验证了破坏状态与声发射空间分布的一致性。建立了声发射空间分布分形维数与应力和能量释放的关系。分形维数的增加对应着应力的减小和能量释放的增加，这与理论分析一致。当单轴压缩分形维数小于2.20、间接拉伸分形维数小于2.57时，层状岩盐试样的应力均大于峰值应力的80%。层状岩盐试样发生大量累积损伤，导致整体破坏。因此，通过检测层状岩盐的应力或能量释放与声发射空间分布分形维数的变化，可以预测层状岩盐的破坏状态。
A rock mechanics test system and the acoustic emission (AE) test system were employed to perform experiments on bedded rock salt samples under uniaxial compression and indirect tension. Based on the basic theory of fractal geometry, a column covering method is proposed to analyze the fractal property of the spatial distribution of acoustic emissions during the rock damage and failure process. The experimental results indicate obvious differences in failure features for different parts of a sample due to the structural differences in bedded rock salt. The consistency between the failure state and the AE spatial distribution is confirmed. The relationships of the stress and energy release with the fractal dimension of the AE spatial distribution are established. An increase in the fractal dimension corresponds to a decrease in the stress and an increase in the energy release, which is consistent with the theoretical analysis. When the fractal dimension obtained from uniaxial compression and indirect tensile tests is less than 2.20 and 2.57, respectively, the stresses in the bedded rock salt sample are over 80% of the peak stress. A great amount of accumulated damage occurs, leading to the global failure of the bedded rock salt sample. Therefore, it is possible to forecast the failure state of bedded rock salt by inspecting the variation between the stress or the energy release and the fractal dimension of the AE spatial distribution.