中文摘要：

通过对取自四川锦屏大理岩试样进行基于扫描电镜的细观损伤力学全程数字化跟踪试验,并对试验结果进行统计分析,得到在单轴压缩过程中微裂纹间距服从变参数的广义极限分布这一结论。基于此,根据宏、细观损伤力学理论描述损伤的特征,在内变量不可逆热力学理论框架下,应用能量耗散原理建立包含宏细观两个尺度损伤信息的统计损伤模型。最后,应用此模型模拟得到大理岩单轴压缩的应力-应变关系及三个损伤变量的发展过程。研究结果表明,模型应力应变曲线处于试验应力应变曲线包络线内,并且包含细观损伤信息的损伤变量D比由宏观物理力学参数角度定义的损伤变量KD、GD对损伤更为敏感,且三个损伤变量的发展具有明显的阶段性。

英文摘要：

The micro-fracturing process of marble samples under uniaxial compression, taken from the surrounding rock of the Jinping II cascade hydropower station, was recorded by using meso-mechanical testing schemes based on the scanning electron microscopy （SEM）. Fracture spacing of these samples is analysed herein by statistical theory and compared with macro-fracturing process, and the probability distribution of micro-fracture spacing is generalized by an extreme-value distribution of damage parameters. Appling the basic principle of energy dissipation, we developed a damage model of macroand meso-fracture information in the framework of irreversible thermodynamics and applied it to simulation of stress-strain relationships. The results show that all the calculated stress-strain curves fall within the range between two experimentally measured envelope curves. The damage parameter D that contains macro- and meso-fracture information is more sensitive to damage condition than the ones DK and Dc containing macro-fracture information only. And the growth of these parameters presents prominent staged features.