冷却热冲击下岩石剩余动力性能及应力波传播特性研究

The investigation of residual dynamic properties of rock after cooling induced thermal shocks is of extreme importance for dynamic analysis of rock engineering, such as feasibility analysis and safety assessment. Firstly, the proposed project performs a series of macro-micro tests to investigate the variations of physical and mechanical property, mineral composition, and micro-structure of rock after thermal shocks induced by natural cooling, water cooling and liquid nitrogen cooling, respectively. The thermal damage evolution of rock as temperature and thermal shock time change is revealed. Secondly, the proposed project performs a series of dynamic tests to investigate the shock resistance properties and wave propagation properties of rock after the three cooling treatments. The dynamic behavior evolution of rock as temperature and thermal shock time change is revealed. Finally, the proposed project performs a series of frequency spectrum analysis to modify the equivalent continuum model. The dynamic response of rock after quick cooling induced thermal shock is studied and residual dynamic modulus is evaluated. Furthermore, the thermal-mechanical coupling effects are systematically investigated.

冷却热冲击下岩石的剩余动力性能以及应力波传播特性研究是高温岩体工程动态破坏机理分析和安全性评价的基础。本项目首先基于多尺度测试，研究高温岩石在自然冷却、射水冷却、液氮冷却三种方式下的物理力学性质、矿物成分、微细观结构的变化规律，揭示岩石在三种冷却方式下随温度、循环热冲击次数的热损伤演化机制；其次，采用冲击力学试验，研究高温岩石在三种冷却方式下的抗冲击力学性能和应力波传播特性，揭示岩石动态力学性能随温度、循环热冲击次数的劣化机制；在此基础上，基于频谱分析理论改进等效连续介质模型，研究高温岩石在三种冷却方式下的动力响应，量化分析残余动力因子，揭示温度、冷却方式、循环热冲击次数、加载类型、载荷幅值、载荷频率等多种耦合因素对岩石剩余动力性能的作用机理。

本项目对冷却热冲击下岩石的剩余动力性能以及应力波传播特性进行了系统研究。首先开展了多尺度测试，研究了高温岩石在自然冷却、射水冷却、液氮冷却三种方式下的物理力学性质、矿物成分、微细观结构的变化规律，揭示了岩石在三种冷却方式下随温度、循环热冲击次数的热损伤演化机制；其次，开展了冲击力学试验，研究了高温岩石在三种冷却方式下的抗冲击力学性能和应力波传播特性，揭示了岩石动态力学性能随温度、循环热冲击次数的劣化机制；在此基础上，提出了基于频谱分析理论的等效连续介质模型，研究了高温岩石在三种冷却方式下的动力响应，量化分析了残余动力因子，揭示了温度、冷却方式、循环热冲击次数、加载类型、载荷幅值、载荷频率等多种耦合因素对岩石剩余动力性能的作用机理。