考虑初始宏细观缺陷的裂隙岩体损伤本构模型研究

针对传统岩石损伤本构模型因对初始状态损伤忽略的假定致使岩石损伤状态表达不足的问题，基于连续损伤力学原理，运用统计损伤学定义了表征含有初始宏细观缺陷的岩体损伤变量，引入表征岩体初始损伤状态的初始损伤系数k，优化了传统损伤本构模型，对建立的损伤演化本构模型和实测数据曲线进行对比分析。研究结果表明:优化后的本构模型对裂隙岩石全应力应变过程拟合精度更高，其损伤演变过程更符合实际，并能反映存在初始损伤的岩石力学特征差异，量化了初始孔隙、裂隙等宏细观损伤在应力环境中的耦合作用，对研究宏细观缺陷岩石损伤场-应力场耦合作用机制具有意义。

Study on constitutive model of fractured rock mass damage considering initial macroscopic and microscopic defects

Aiming at the problem that the rock damage state is expressed insufficiently due to the assumption of neglecting the initial state damage in the traditional constitutive model of rock damage, based on the principle of continuous damage mechanics, the rock mass damage variable representing the initial macroscopic and microscopic defects was defined by using the statistical damage theory. The initial damage coefficient k representing the initial damage state of rock mass was introduced to optimize the traditional damage constitutive model. At the same time, the established damage evolution constitutive model and the measured data curve were compared and analyzed. The results showed that the optimized constitutive model had higher fitting accuracy to the full stress strain process of fractured rock, and the damage evolution process was more realistic, which could reflect the difference of rock mechanics characteristics with the initial damage. The coupling effect of macroscopic and microscopic damage in the stress environment was quantified, such as the initial pore, fracture, etc. It is of great significance for studying the coupling effect mechanism of damage field and stress field of rock containing the macroscopic and microscopic defects.