中文摘要：

板岩是一种非均质、连续一非连续介质，包含有微裂隙、微孔洞和微构造等，在力学、渗流、热传导等诸多方面均表现出明显的各向异性。选取锦屏水电站辅助洞泥质板岩试样，采用超薄金刚石锯片在标准岩样上预制一对三维裂纹，并应用岩土CT实验技术，开展水平和垂直层理方向加载条件下裂纹演化的细观尺度观测，分别得到了天然和预制双裂纹板岩破坏过程的细观表现特征，对比分析了水平和垂直层理方向加载条件下板岩裂纹起裂、扩展和破坏模式的不同，并对基于密度统计的岩石细观损伤变量定义方法的局限性进行了分析和讨论，为研究板岩的力学各向异性提供了新思路。

英文摘要：

Slate is a heterogeneous and continuous-discontinuous material filled with micro-fractures, pores, fabrics, etc., and shows anisotropy in geological behavior, fluid flow and heat transfer. The slate samples from the auxiliary tunnel of Jinping hydro power station were cracked with an artificial diamond saw blade of ultrathin. The failure of samples under the uniaxial compression was observed with the 3D X-ray computed tomography system which is applicable to rock and soil. The difference between the sample failures with the loading direction perpendicular to and parallel to the bedding plane was obtained and the damage evolution of slate was also discussed on the meso-scale.