基于Bloch动态均匀化理论的节理岩体等效动力参数及频散效应研究

节理岩体是一种非连续材料，有显著的频散效应，但在大尺度动力问题的计算中常需提取其等效力学参数，并简化为均匀连续介质。本项目综合理论分析、室内试验与数值模拟，提出获取节理岩体等效动力参数的动态均匀化方法并研究其频散效应。根据节理的空间分布，选取合适的代表性体积单元，利用Bloch波理论得到不同频率应力波的相速度，求得节理岩体的等效动力参数及其频散曲线。结合宏观尺度的等效动力参数与细观尺度的代表性体积单元振动模态，阐明节理岩体的频散效应及其机理。基于动态均匀化方法，分析节理的空间分布特征、岩石与节理的力学特性等因素的影响，归纳动荷载作用下岩体质量的评价准则。进行分离式霍普金森杆试验，与理论结果相互验证。在有限元软件中嵌入考虑频散效应的动力本构关系，将动态均匀化方法用于实际工程问题的分析中。研究成果可为我国基础设施建设、地下空间开发、资源开采等提供支撑，具有重要的理论意义和工程价值。

Jointed rock masses are heterogeneous materials with significant dispersion effects. They are usually simplified to uniform continuous medium in large-scale dynamic analysis and represented by several effective mechanical parameters. This project systematically proposes a dynamic homogenization method for obtaining the effective dynamic mechanical parameters of jointed rock masses and investigating their dispersion effects based on theoretical analysis, laboratory tests, and numerical simulation. According to the spatial distribution of joints, Representative Volume Element (REV) is selected. Using Bloch wave theory, the phase velocities of stress waves with different frequencies are obtained. Thereby the effective dynamic mechanical parameters and their dispersion curves are calculated. Combining the macroscopic effective dynamic parameters with the mesoscopic vibration modes of REV, the dispersion effect of jointed rock masses and its mechanism can be investigated. Based on the dynamic homogenization method, influence factors including the spatial distribution of joints and the mechanical properties of rocks and joints are analyzed. The criteria for quality evaluation of rock masses under dynamic actions are further summarized. Employing the Split Hopkinson Pressure Bar instrument, the dynamic homogenization theory can be verified and improved. The dynamic constitutive relationship considering the dispersion effect can be embedded in the finite element analysis software, and via this, the dynamic homogenization method can be used in the analysis of practical engineering projects. The output of this research can support the construction of infrastructures, underground space exploitation, mining projects, etc., and have significant impacts on both theory and practice.