循环剪切条件下结构面磨损微观机制及力学特性分析模型

Mechanical properties charge rule of rock joints under cyclic shear loading, and relationship to initial waviness, normal stress and JCS is researched based on the systematic experiment results. Both contact characteristics and damage characteristics are analyzed based on the experiment results, and then set up a microscopic generalized contact model for rock joints. The destruction of the convex body area and failure modes and evolution process of waviness for rock joints with different initial waviness, normal stress and JCS are analyzed, which reveals the cumulative failure process and degradation mechanism mechanical characteristics. Combined with micro analysis results and macro experiment phenomenon, an equivalent failure model was set up to characterize the destruction features and cumulative damage process of rock joints under cyclic shear loading. And furthermore, the shear strength formula was established which reveals cyclic shear effect and includes the initial waviness, normal stress and JCS factors. According to the equivalent failure model and disturbed state concept theory, define reference state; define perturbation factors and constructing its evolution model, and determine the model parameters.The constitutive model for rock joints under cyclic shear loading was established, which characterize the destruction features and cumulative damage process of the cyclic shear.The research production provide a dynamic mechanical parameters of joints and analysis model, and can effectively improve the accuracy of large rock engineering safety evaluation under seismic load.

以系统的室内实验为基础，分析循环剪切荷载作用下结构面力学特性的变化规律，及其与初始起伏度、法向应力、壁岩强度等因素之间的相关关系。基于结构面起伏体的接触和破坏特征分析, 建立结构面剪切的微观概化接触模型。研究不同起伏体形态、材料参数及应力条件下凸起体的破坏区域、形式和演化过程；揭示结构面起伏体在循环剪切中的累积破坏过程和力学特性的劣化机理。结合微观分析成果与宏观试验现象，提出体现循环剪切荷载作用下结构面起伏体破坏特征和累积破坏过程的等效破坏模型，建立考虑循环剪切累积效应并包含起伏度、法向应力、岩壁强度等因素的剪切强度公式。基于等效破坏模型和扰动状态理论方法，选取参考状态及扰动因子，构建扰动因子演化模型并确定模型参数，建立体现循环剪切过程中结构面凸起体破损程度和过程的本构模型。研究成果能够提供结构面动态的力学参数和分析模型，有助于提高目前地震荷载作用下大型岩体工程安全性评价工作的准确性。

利用相似材料制备不同起伏特征的人工结构面试样，基于系统的室内实验研究了循环剪切荷载作用下结构面力学特性的变化规律，及其与初始起伏度、法向应力、壁岩强度等因素之间的相关关系。以结构面起伏体的接触和破坏特征分析成果为基础, 建立了结构面剪切的微观概化接触模型。通过不同起伏体形态、材料参数及应力条件下凸起体的破坏区域、形式和演化过程分析；揭示了结构面起伏体在循环剪切中的累积破坏过程和力学特性的劣化机理。结合微观分析成果与宏观试验现象，提出体现循环剪切荷载作用下结构面起伏体破坏特征和累积破坏过程的等效破坏模型，建立考虑循环剪切累积效应并包含起伏度、法向应力、岩壁强度等因素的剪切强度公式。基于等效破坏模型和扰动状态理论方法，建立体现循环剪切过程中结构面凸起体破损程度和过程的本构模型。研究成果提供的结构面动态的力学参数和分析模型，为目前准确评价地震荷载作用下大型岩体工程安全性提供了重要基础。