| 基于3D-DIC的砂岩裂纹扩展及损伤监测试验研究 |
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| 引用本文： | 范杰,朱星,胡桔维,唐垚,贺春蕾.基于3D-DIC的砂岩裂纹扩展及损伤监测试验研究[J].岩土力学,2022,43(4):1009-1019. |
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| 作者姓名： | 范杰 朱星 胡桔维 唐垚 贺春蕾 |
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| 作者单位： | 1. 成都理工大学 地质灾害防治与地质环境保护国家重点实验室，四川 成都 610059； 2. 成都理工大学 环境与土木工程学院，四川 成都 610059；3. 成都理工大学 信息科学与技术学院，四川 成都 610059 |
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| 基金项目： | 国家自然科学基金（No.41877254）；;四川省科技计划项目（No.2019YJ0534）；;国家重点研发计划（No.2019YFC1509602）~~； |
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| 摘 要： | 裂纹监测对岩石损伤演化的认识至关重要。为研究岩石裂纹扩展及损伤变形特性，开展了含不同倾角（0°～90°）预制裂隙的标准细黄砂岩样的单轴压缩试验。利用三维数字图像相关技术（3D-DIC）获取岩样三维空间坐标下的应变分布，并结合声发射从光学与声学的角度监测了裂纹的扩展演化。由此提出了一种裂纹主应变的计算方法，定量表征岩石劣化的损伤变量D值。最后，探讨了由声发射与损伤变量D值确定岩样特征强度的影响因素。结论如下：（1）裂纹主应变反映了岩样受荷过程中同源裂纹在时间上的变化速率与空间上的扩展趋势，能较好地表征岩石的开裂行为；（2）声发射适用于确定岩样的起裂应力，不适用于损伤应力的确定，损伤变量D值所确定的起裂应力滞后于声发射，但适用于损伤应力特征值的确定；（3）结合声发射与DIC技术确定的归一化起裂应力范围为0.63～0.94、归一化损伤应力的范围为0.83～0.99；（4）预有裂隙会影响岩石的材料力学性能。随着倾角的增加，岩石的起裂应力、损伤应力及峰值应力呈增长的趋势，由于难以形成局部应变场聚集，裂纹的萌生与起裂更加困难。结果表明，3D-DIC技术的利用可以提高对岩石开裂行为的理解，对岩石的损伤监测与判识更有重要的意义。
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| 关 键 词： | 3D-DIC技术 预制裂隙 特征强度 损伤变量 裂纹监测 |
| 收稿时间： | 2021-07-23 |
| 修稿时间： | 2021-11-22 |
Experimental study on crack propagation and damage monitoring of sandstone using three-dimensional digital image correlation technology |
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| FAN Jie,ZHU Xing,HU Ju-wei,TANG Yao,HE Chun-lei.Experimental study on crack propagation and damage monitoring of sandstone using three-dimensional digital image correlation technology[J].Rock and Soil Mechanics,2022,43(4):1009-1019. |
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| Authors: | FAN Jie ZHU Xing HU Ju-wei TANG Yao HE Chun-lei |
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| Institution: | 1. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, Sichuan 610059, China;
2. College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, China;
3. College of Information Science and Technology, Chengdu University of Technology, Chengdu, Sichuan 610059, China |
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| Abstract: | Crack monitoring is highly important to understand rock damage evolution. In order to study the characteristics of rock crack propagation and damage deformation, uniaxial compression tests were carried out on standard fine yellow sandstone samples embodied prefabricated cracks with different inclination angles (0°?90°). The 3D-DIC technology was used to obtain the strain distribution of the rock sample in the three-dimensional space coordinates, and combined with acoustic emission, the crack propagation and evolution were monitored from the perspective of optics and acoustics. Therefore, a method for calculating the principal strain of cracks was proposed, which quantitatively characterizes the damage variable D value of rock deterioration. Finally, the influencing factors of determining the characteristic strength of the rock sample by the acoustic emission method and the damage variable D value were discussed. The conclusions are as follows: (1) The principal strain of the crack reflects the time-varying rate and the spatial expansion trend of the homologous cracks during the loading process of the rock sample, which can better characterize the cracking behavior of the rock. (2) The acoustic emission method is suitable for determining the initiation stress of a rock sample, but not for determining the damage stress. The crack initiation stress of damage variable D value lags behind that of the acoustic emission method, but it is suitable for determining the characteristic value of the damage stress. (3) The normalized crack initiation stress range determined by combining acoustic emission and DIC technology is 0.63?0.94, and the normalized damage stress range is 0.83?0.99. (4) Prefabricated cracks will affect the mechanical properties of rock materials. With the dip angle increasing, the crack initiation stress, damage stress and peak stress of the rock show an increasing trend. The initiation of cracks become more difficult because it is difficult to form a local strain field accumulation. The results show that 3D-DIC technology can improve the understanding of rock cracking behavior, and is more important for rock damage monitoring and identification. |
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| Keywords: | 3D-DIC technology prefabricated cracks characteristic strength damage variables crack monitoring |
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