Time-Dependent Propagation of 3-D Cracks in Rocks Under Hydromechanical Coupling
Time-Dependent Propagation of 3-D Cracks in Rocks Under Hydromechanical Coupling
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DOI：
10.1007/s00603-019-02020-2
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发表时间：
2019-12
影响因子：
6.2
通讯作者：
J. Mei;Lei Yang;Xiangchao Sheng;Guangxiao Song;Weimin Yang;Bo Zhang
中科院分区：
文献类型：
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作者：
J. Mei;Lei Yang;Xiangchao Sheng;Guangxiao Song;Weimin Yang;Bo Zhang
水-力耦合作用下的裂纹扩展与岩石破坏具有典型的时变特征，亚临界裂纹扩展是岩石失稳的重要原因之一。通过含单内三维裂缝砂浆试件的流变试验和数值模拟，研究了裂缝扩展的时变特征、岩石破坏模式以及水压和裂缝倾角的影响。流变试验结果显示砂浆试件在水力耦合作用下呈现拉剪破坏模式，宏观断裂贯穿试件上下端。裂纹扩展速率先减小后增大。根据裂纹扩展速率与断裂参数的关系，将裂纹扩展过程分为三个阶段。水压对裂纹扩展速率的促进作用显著缩短了岩石破坏所需的时间，但对岩石的长期稳定性有负面影响。在水-力耦合作用下，倾角为45的裂缝更容易引起岩石破坏，而倾角较大的裂缝具有较好的长期稳定性。
Crack propagation and rock failure under hydromechanical coupling have typical time-dependent characteristics, and the subcritical crack propagation is one of the most important causes of rock instability. Rheological tests based on mortar specimens containing single internal 3-D cracks and the corresponding numerical simulations are carried out to investigate the time-dependent characteristics of the crack propagation, the failure mode of rocks, and the effects of water pressure and crack dip angle. The mortar specimen exhibits a tensile-shear failure mode under the hydromechanical coupling as observed in rheological tests, and a macro-fracture penetrates the upper and lower ends of the specimen. The propagation rate of the crack decreases first and then increases. The crack propagation can be divided into three stages according to the relationship between the propagation rate and fracture parameters. The water pressure significantly reduces the time required for rock failure due to its promoting effect on the crack propagation rate, which has negative effects on the long-term stability of rocks. Cracks with a dip angle of 45 are more likely to cause rock failure under hydromechanical coupling, while cracks with larger dip angles exhibit a better long-term stability.