Understanding the cracking characteristics of shale is necessary for oil and gas exploitation engineering. The cracking behaviours and failure modes of obliqued-layers shale specimens were studied under uniaxial compression stress. The acoustic emission response was monitored, and the displacement and strain fields were calculated with digital image correlation (DIC). For the flawed shale specimens, the cracks initiated from the flaw tips most of the time and propagated towards the boundaries, and bedding layers led to the branching and diversion of the crack path. The first cracks did not always start from the flaw tips due to microstructure distribution. Tensile cracks dominated the cracking process, and shear cracks mainly contributed to the final failure of the flawed shale specimens. The failure modes remained unchanged when the flaw rotated from 30° to 60°. However, shear cracks along the bedding layers and tensile cracks parallel to the maximum principal stress dominated the failure of the intact shale specimen. The flaw controlled the location of cracking initiation, and the bedding layers affected the cracking path for the flawed specimen. The bedding layers also control the failure mode of the intact specimen. The experimental results contribute to the understanding of cracking properties in layered anisotropic materials.

了解页岩的裂缝特征对于油气开采工程是必要的。研究了斜层页岩试件在单轴压缩应力作用下的开裂行为和破坏模式。监测声发射响应，并通过数字图像相关性（DIC）计算位移和应变场。对于有缺陷的页岩样品，裂缝大多数时候是从缺陷尖端开始并向边界扩展，而层理层导致裂缝路径的分支和转移。由于微观结构的分布，最初的裂纹并不总是从裂纹尖端开始的。拉伸裂纹在裂纹形成过程中占主导地位，而剪切裂纹则主要是导致有缺陷的页岩样品最终破裂的原因。当缺陷从30°旋转到60°时，失效模式保持不变。然而，沿着层理层的剪切裂缝和平行于最大主应力的拉伸裂缝主导了完整的页岩试样的破坏。缺陷控制了裂纹萌生的位置，并且层理层影响了有缺陷试样的裂纹路径。垫层还控制完整样本的破坏模式。实验结果有助于理解层状各向异性材料的开裂性能。垫层还控制完整样本的破坏模式。实验结果有助于理解层状各向异性材料的开裂性能。垫层还控制完整样本的破坏模式。实验结果有助于理解层状各向异性材料的开裂性能。