充填岩石节理的剪切力学模型和颗粒运移破碎过程的宏细观研究

Rock massess present in nature are generalized characterized by rock joints that are usually filled with clay or particulate matter. As the weakest elements in a rock mass, it is important to quantify the peak shear strength of infilled joints in design and construction of surface and undergroun rock structures. The shear behaviors are different for rock joints infilled with varied materials. In the present study, we want to investigate the shear behavior of rock joints filled with unsaturated clay, overconsolidated clay, non-cemented and cemented particulate matter, respectively, based on experimental study, theoretical and numerical analysis. After analyzing the shear deformation of infilled rock joints, the factors influencing the peak shear strength displacement are analyzed and the corresponding model will be proposed. Based on analyzing the shear mechanism and the shear strength, we want to propose new criteria with consideration of the physical properties of infilled material, such as saturation, consolidation degree and the particulate characterization, respectively. Scale effect and particle movement are investigated by laboratory test and numerical modeling using distinct element method. On application of the theoretical results to the practice of engineering, it is of great significance for improving the mechanical properties of jointed rock masses and also for the deformation control and stability analysis of rock masses in dam, slope and so on.

充填节理是普遍存在的且通常是岩体中的薄弱环节，研究充填节理的剪切力学性质对地面/地下岩石工程的建设至关重要。充填物性状不同，充填节理的剪切力学性质有较大差异。本项目拟研究分别充填非饱和黏土、超固结黏土、无胶结颗粒材料和胶结颗粒材料的岩石节理的剪切力学性质，以试验为基础并结合理论分析和数值仿真进行研究。通过对含不同充填物岩石节理剪切变形规律的研究，分析影响峰值剪切位移的因素并建立相应的模型；通过对含不同充填物岩石节理剪切强度规律的研究，在弄清充填物性状（饱和度、超固结度和颗粒特征）对剪切破坏机理影响的基础上，分别建立峰值剪切强度准则。基于物理试验和数值仿真，研究充填节理剪切力学性质的尺度效应，并分析压剪作用下颗粒运移破碎过程的细观力学特征。结合工程案例开展理论成果的应用研究，对完善节理岩体的力学性质研究具有重要的意义，可为坝基、边坡等工程岩体的变形控制和稳定性分析提供理论支持。

充填节理是普遍存在的且通常是岩体中的薄弱环节，研究充填节理的剪切力学性质对地面/地下岩石工程的建设至关重要。充填物性状不同，充填节理的剪切力学性质有较大差异，项目主要研究了填充颗粒材料的岩石节理的剪切力学性质。基于颗粒离散元数值平台，开发了模拟压剪作用下模拟颗粒破碎过程的岩石节理直剪程序。通过对含不同颗粒形状（圆形颗粒、椭圆形颗粒）的岩石节理剪切过程的研究，分析了剪切过程中颗粒的运移、破碎过程。重点分析了剪切应力的变化、剪胀以及颗粒碎裂过程的微观裂纹演化规律。针对数值试验的特点，分析了球单元摩擦系数、粘结强度和接触模量对颗粒运移、破碎过程的影响。研究了干湿循环作用下岩石节理的剪切力学性质，获得了剪切强度参数（摩擦角、粘聚力）随干湿循环次数增加的变化规律，初步阐述了水岩相互作用引起的峰值剪切强度弱化机理。研究了高温作用后花岗岩节理的峰值剪切强度演化规律，建立了考虑温度影响的峰值剪切强度经验准则。