The objective of the present study is to investigate deformation behavior of anisotropic claystone in relation with material heterogeneity. For this purpose, a set of five triaxial compression tests are performed on samples of Callovo-Oxfordian (COx) claystone under in-situ X-ray micro-tomography monitoring. Complete 3D images of the samples full loading history were recorded and analyzed by digital volume correlation method. Full non-uniform strain fields were determined and averaged global strains were calculated. As novelty, we have particularly investigated the effects of bedding planes, initial cracks and confining stress on strain fields. The results indicate that the structural anisotropy of COx claystone has a strong influence on the local strain distribution and cracking process. The confining pressure has also an important impact on the strain fields and failure modes of samples in the triaxial tests. The cracking process of samples is strongly correlated with radial strain distribution.

本研究的目的是研究各向异性粘土岩的变形行为与材料不均匀性的关系。为此，在原位 X 射线显微层析成像监测下，对 Callovo-Oxfordian (COx) 粘土岩样品进行了一组五项三轴压缩试验。通过数字体积相关法记录和分析样品满载历史的完整 3D 图像。确定了完整的非均匀应变场并计算了平均全局应变。作为新颖性，我们特别研究了层理平面、初始裂缝和围应力对应变场的影响。结果表明，COx粘土的结构各向异性对局部应变分布和开裂过程有很大影响。围压对三轴试验中试样的应变场和破坏模式也有重要影响。样品的开裂过程与径向应变分布密切相关。