基于结构特征的锚注加固节理岩体破坏机理研究

Bolting and grouting technology has important applications in jointed rock engineering, in this case, it effectively avoids the shortcomings and disadvantages of grouting alone or bolting, and it has broad application prospects in mountainous rock mass engineering, but the failure mechanism of the reinforcing structure is unclear, and it has become the bottleneck of restricting the design standardization of bolting and grouting engineering and rationalization of engineering control. This project makes the bolting and grouting in the jointed rock masses as the research object, with the research methods of physical tests, theoretical analysis and numerical simulation, and reveals the failure mechanism of bolting and grouting in the jointed rock masses. The specific studies of this project includes: exploring the destruction characteristics, stress distribution and evolution laws of bolting and grouting in jointed rock masses under shear and drawing loads; analyzing the jointed forms effect of bolting and grouting, the material properties effect of bolting and grouting, the change of the structure size for the failure effect of bolting and grouting, and establishing the constitutive equations and ultimate failure capacity formula of the bolting and grouting in the jointed rock masses; verifying destruction process of bolting and grouting reinforcement in the jointed rock masses with FLAC3D simulation under the same condition. This project aims to explore the internal mechanism of bolting and grouting in jointed rock masses failure, improve the reliability of bolting and grouting engineering control, and lay the theoretical and technical basis for the effective control of bolting and grouting engineering and design standardization.

锚注加固技术在节理岩体工程中具有重要的应用价值，其合理的结构形式有效地规避了节理单独注浆或加锚所存在的弊端与不足，使其在山地岩体工程中拥有广阔的应用前景，但该加固结构的破坏机理目前尚不清楚，成为制约锚注工程设计规范化及工程控制合理化的瓶颈，本项目以锚注节理岩体为研究对象，拟通过物理试验、理论推导及数值模拟的研究方法，揭示锚注加固节理岩体的破坏机理。具体研究内容包括：探索剪切及拉拔荷载作用下锚注节理岩体的破坏特征，应力应变分布及演化规律；分析节理形态、锚注材料性能、结构尺寸的变化对锚注结构破坏效应的影响，建立锚注节理的极限破坏承载力公式；在相同条件下进行锚注节理破坏过程的FLAC3D仿真验证，本项目旨在探索锚注加固节理岩体破坏的内在机制，提高锚注加固工程控制的可靠度，为锚注工程有效控制及设计的规范化奠定理论基础。

锚注加固节理岩体的抗剪切及抗拉拔极限承载力受控于锚注节理的结构特征，研究不同结构锚注节理岩体的力学特性及破坏机理具有重要的理论和应用价值，为此，本项目构建多组物理试验及数值模拟试验模型，对试验模型进行剪切及拉拔极限破坏试验，观察模型的破坏特征，得出试件的全程应力-应变曲线，测取锚注岩体结构面不同区域的应力应变参数值，通过物理试验获得关键的研究数据，结合数值模拟计算得出模型的应力场及位移场，运用经典力学理论推出不同结构锚注节理岩体的极限抗剪切承载力及抗拉拔承载力公式； 研究结果表明：锚注节理岩体的抗剪切及抗拉拔极限承载力与锚杆的数量、锚杆的倾角、锚杆体的强度、节理注浆层的厚度及强度密切相关，从而揭示了锚注结构参数与其极限承载力的对应关系，研究结果对锚注加固节理岩体的设计理论及相应规范的修订具有重要的理论指导意义。