循环冲击载荷与化学腐蚀耦合作用下砂岩损伤机理研究

Mechanical and chemical are the two main effects inside the Earth. The stability of the rock mass with complicated engineering geological conditions in rock blasting process is greatly affected by the coupling effect of mechanical and chemical corrosion. At present, the mechanical properties of rock under the coupling effect of mechanical and chemical corrosion is one of the topics at the forefront of rock mechanical circle worldwide, but the study of rock damage mechanism under coupling effect of cycle impact loading and chemical corrosion is still insufficient. Therefore, using sandstone as the research object, this study is based on preliminary research of the dynamic mechanical properties of sandstone under cyclic impact loading and weakening fatigue effect of rock blasting in hydrate engineering. Using the improved SHPB test technology combining stress wave theory, this study reveals the patterns of strength and deformation of sandstone under different combinations of stress in the impact loading cycle coupled with chemical etching process. By analyzing the main factors causing the degradation of the mechanical properties of sandstone and its pattern, this study establishes fatigue damage model of sandstone under coupling effect of cycle impact loading and chemical corrosion. Finally, the fatigue damage mechanism of sandstone under cycle impact loading and chemical corrosion is revealed, which will lay the foundation for the safety of rock structure, efficient construction and operation in complex geological engineering projects.

力学与化学作用是地球内部最主要的两类作用。复杂地质条件工程岩体爆破开挖过程中，其稳定性因力学与化学腐蚀耦合作用受到极大影响。当前，对力学与化学腐蚀耦合作用下的岩石力学性质研究是岩石力学领域国际前沿课题之一，但对岩石在循环冲击载荷与化学腐蚀耦合作用下的损伤机理研究尚显不足。因此，本项目基于前期对循环冲击载荷作用下砂岩的动态力学特性研究及水化工程岩体爆破疲劳损伤弱化效应研究，以砂岩为研究对象，采用改进的SHPB技术并结合应力波理论，揭示不同应力组合砂岩在循环冲击载荷与化学腐蚀耦合过程中的强度和变形变化规律，分析得出耦合作用下的砂岩力学性能劣化的主要影响因素与方式，确定砂岩在循环冲击载荷与化学腐蚀耦合作用下损伤变量的定义方法，建立相应的疲劳损伤模型，最终揭示循环冲击载荷与化学腐蚀耦合作用下砂岩疲劳损伤机理，为复杂地质工程岩体安全、高效施工和运营奠定基础。

力学与化学作用是地球内部最主要的两类作用，力学与化学腐蚀耦合作用下的岩石力学性质研究是岩石力学领域国际前沿课题之一。本项目针对实际工程面临的复杂地质问题，基于前期对循环冲击载荷作用下水化工程岩体爆破疲劳损伤弱化效应研究，以砂岩为研究对象，采用改进的SHPB技术并结合SEM扫描电镜，从宏观和细观角度分析了冲击荷载与化学侵蚀耦合作用下岩体损伤动态力学性能，探究了冲击荷载、静载与化学侵蚀耦合作用下砂岩强度疲劳劣化演化规律及破坏变形规律，揭示在循环冲击载荷与化学腐蚀耦合作用下砂岩损伤机理，进而为化学腐蚀地质条件下岩体爆破开挖过程中的安全、高效施工和运营提供理论依据。根据等截面杆件应力波传播特性研究的基础上，针对变截面构件受到动静组合荷载作用的工程实例，开展了基于轴向静载下直锥铝杆的一维应力波传播试验，获得了微孔隙耗能和横截面扩散对直锥铝杆中应力波的幅值衰减效应规律，揭示了轴向静载对变截面杆中应力波波形、传播速度和幅值的作用机理。此外，针对深部矿山微震地应力监测，构建了基于权重的计算值判别指标的波微震事件和爆炸的高精度辨识方法和关键技术，获得了基于聚类和不确定测量高陡开采边坡稳定性分析方法，提高微震监测数据处理的速度和精度，为大型矿山边坡岩体稳定性可靠计算及高效的微震检测技术奠定理论基础，具有重要的科学意义。