蠕变-疲劳交互作用下岩石变形损伤断裂机理研究

The instability of engineering rockmass frequently occurs in weak earthquake zone with low-frequency. In this project, we focus on the the key scientific issue, viz., damage and fracturing of rock under fatigue and creep interaction and aim at gaining an insight into the damage and fracturing mechanism of rock under fatigue and creep interaction. A series of loading experiments and AE (acoustic emission) tests on rock under various stress levels, stress amplititudes, confining pressures, loading durations, and frequencies are performed according to pre-designed creep and fatigue stress paths to study the characteristics of deformation and damage evolution and to investigate the effect of stress levels, stress amplititudes, loading durations, and frequencies on deformation and damage. Based on above, we will derive a mechanical damage model of rock under fatigue and creep interaction, estabilish numerical method of describe the proposed model of rock under fatigue and creep interaction, carry out large-scale numerical simulations on rock damage and fracturing under fatigue and creep interaction, reveal the damage and failure mechanism of rock under fatigue and creep interaction, and propose a feasible and relible life estimation model of rock applicable to rock engineering in field. It is of great importance to control and prevent the catastrophic creep failure of rock mass and minimizes the impact of rockmass instability hazards on rock engineering activities, meanwhile, it is also of significance to develop a better understanding of the safe and efficient rock engineering design and operation and provide a theoretical basis to predict the deformation and long-term stability of rock engineering.

本项目以处于低频震源环境中工程岩体的变形失稳灾害为研究背景，以蠕变-疲劳交互作用下岩石的变形损伤失稳这一关键科学问题为核心，以探究蠕变-疲劳交互作用下岩石变形损伤演化规律为目标，基于一定的蠕变-疲劳载荷路径开展不同应力水平、应力幅值、围压、保载时间、频率等条件下的岩样变形破裂及声发射试验，研究蠕变-疲劳交互作用下岩石变形损伤演化规律及各因素对岩石变形损伤的影响规律，建立蠕变-疲劳交互作用下的岩石变形损伤失稳数学力学模型，编制开发蠕变-疲劳交互作用下岩石变形损伤过程数值仿真模拟方法，并开展一系列蠕变-疲劳交互作用下岩石变形损伤失稳的大规模数值试验研究，揭示蠕变-疲劳交互作用条件下岩石的变形损伤过程及其失稳破坏机理，提出符合工程实际且便于现场应用的岩石失稳寿命估计模型，以期为工程岩体的变形失稳控制方法及长期稳定性预测提供理论和应用基础。

本项目以处于低频震源环境中工程岩体的变形失稳灾害为研究背景，以蠕变-疲劳交互作用下岩石的变形损伤这一关键科学问题为核心，以探究蠕变-疲劳交互作用下岩石变形损伤演化规律为目标，基于一定的蠕变、疲劳载荷路径开展了不同应力水平、应力幅值、围压、保载时间等条件下的岩样变形破裂试验，研究了蠕变-疲劳交互作用下岩石变形损伤演化规律及各因素对岩石变形损伤的影响规律，研究表明蠕变和疲劳对岩石具有本质特性一致的损伤弱化作用，据此建立了基于应力腐蚀理论的蠕变-疲劳交互作用下的岩石变形损伤失稳数学力学模型，开发了蠕变-疲劳交互作用下岩石变形损伤过程数值仿真模拟方法，并开展一系列蠕变-疲劳交互作用下岩石变形损伤失稳的数值模拟研究，揭示了蠕变-疲劳交互作用条件下岩石的变形损伤过程及其失稳破坏机理。通过本项目研究，项目组发表论文32篇，国际期刊SCI收录论文22篇（其中合作发表ESI高被引论文1篇，SCI一区论文13篇）、EI收录论文5篇；申请国家发明专利4项，授权计算软件著作权12项。获得教育部高科学研究优秀成果科技进步二等奖1项、辽宁省自然科学奖1项。培养博士后1名，博士研究生毕业2名，硕士研究生毕业4名。