基于3D⁃DIC技术的约束岩石裂缝扩展研究

采用 RMT-301B岩石与混凝土力学实验系统对施加预应力值为峰值强度 20 %、40 %、60 %的泥质白云 岩进行单轴压缩实验，并借助三维数字图像相关技术(3D-DIC)测试系统观测受约束岩石试样的变形和破坏形 态，研究泥质白云岩在约束条件下的位移场和 Tresca应变场的演化过程．结果表明：(1) 岩石的破坏过程是由 内向外扩展，当应力积累超出岩石承受范围后，岩石出现裂纹，随后裂纹尖端继续扩展，应力也发生了重分 布，岩石内部多组裂纹开始联合扩展、贯穿，直到试件发生完全破坏．(2) 含约束岩石在单轴压缩下一共有轴 向劈裂破坏、沿片理破坏、Y形破坏、共轭剪切破坏四种破坏形态，且以轴向劈裂破坏为主

Research on Constrained Rock Crack Propagation Based on 3D-DIC Technology

Uniaxial compression tests were carried out on the argillaceous dolomite with prestress of 20 %, 40 % and 60 % peak intensity using rock mechanics test system RMT-301B. The three-dimensional digital image correlation (3D-DIC) test system was used to observe the deformation and failure configuration of the constrained rock samples. The evolution process of displacement field and Tresca strain field of argillaceous dolomite under the constraint condition were calculated and analyzed. The results show that: (1) Failure process of the rock expands from the inside to the outside. When the accumulated stress exceeds the bearing range of the rock, the cracks appear in the rock, then the crack tip continues to propagate, and the stress is redistributed. Multiple groups of cracks inside the rock jointly expand, penetrate, and overlap until the specimen is completely destroyed. (2) Under uniaxial compression, the rock with restraint has four failure modes, i. e., axial splitting failure, foliation failure, Y-shaped failure, and conjugate shear failure, with the axial splitting failure being the main mode