Macroscale fracture of rocks is a progressive process consisting of the initiation, propagation and coalescence of numerous microcracks, but the micro- and meso-crack propagation process and the accuracy parameters of multiscale crack evolution timely have not been studied systematically. This study investigates the micro- and meso-damage evolution characteristics based on in-situ scanning electron microscopy (SEM) tests of marble specimens under compression. The propagation and evolution characteristics of microcracks at different locations in marble specimen under load are analyzed in detail. The qualitative analysis of micro- and meso-crack propagation of marble specimen under different loading is performed. The results show that during the compression process of marble from a microscopic point of view, there are mainly three types of microcracks between mineral crystals and mineral crystals: through-grain cracks, transgranular cracks and intragranular cracks. The microcracks that dominate the failure of marble samples are intergranular cracks, and intragranular cracks do not play a significant role. The initiation and evolution of micro-fractures are carried out in zones. Unlike the macro-scale, which is basically a single-wing crack initiation, multiple micro-wing cracks initiate from the end of a prefabricated crack, and some micro-cracks close successively during the loading process, the main wing cracks also undergo a slow or even non-propagating stage. Distribution rules of different micro-parameters are obtained, the transformation from micro-scale to meso-scale is realized. Besides the study provides parameters for the study of a multi-scale theoretical model of rock deformation and failure. Different samples have different characteristics of damage expansion, and the warning before instability is different. This study will provide a warning for possible larger fractures in engineering under different conditions.

岩石的宏观断裂是一个由许多微裂纹的萌发，传播和聚结组成的渐进过程，但是对微裂纹和细裂纹的扩展过程以及多尺度裂纹演化的精度参数尚未进行系统的研究。这项研究基于压缩状态下大理石样品的原位扫描电子显微镜（SEM）测试，研究了微观和细观损伤演化特征。详细分析了载荷作用下大理石试样中不同位置的微裂纹的传播和演化特征。对不同载荷下大理石试样的微裂纹和细裂纹的定性分析。结果表明，在大理石压缩过程中，从微观角度来看，矿物晶体和矿物晶体之间的微裂纹主要有三种类型：贯穿晶粒裂纹，透晶裂纹和晶内裂纹。支配大理石样品破坏的微裂纹是晶间裂纹，而晶内裂纹没有发挥重要作用。微裂缝的产生和演化是在区域内进行的。与宏观尺度不同，宏观尺度基本上是单翼裂纹的萌生，而多个微翼裂纹是从预制裂纹的末端开始的，在加载过程中一些微裂纹是连续关闭的，主翼裂纹也经历了缓慢的变化。甚至是非传播阶段。得到了不同微观参数的分布规律，实现了从微观到中尺度的转变。此外，该研究为岩石变形和破坏的多尺度理论模型的研究提供了参数。不同的样品具有不同的破坏扩展特性，并且在不稳定之前的警告也不同。这项研究将为在不同条件下工程中可能出现的较大裂缝提供警告。