裂隙硬岩高温卸荷各向异性损伤流变特性与破坏机理研究

Splitting failure of underground caverns of large hydropower station is a special engineering damage phenomenon knows as the unloading deformation of hard brittle rock mass due to the cavern excavation under 3D complex condition, which is one of the important factors affecting the safety of underground construction and the long time running stability. The deep rock mass is often accompanied by high temperature environment, it is hard to distinguish them from the deformation caused by unloading or the deformation caused by temperature, and also the failure mechanism of excavation unloading of deep cavern at high temperatures has yet to know clearly. In order to research the scientific problem, the project will take Qirehataer hydropower station project that appears the phenomenon of splitting failure as the background engineering. The project will take means of model test, theoretical research and numerical analysis to simulate the damage condition and forming process of excavation unloading at high temperatures, explore the stress condition and deformation rule, clarify the damage evolution and failure mode, reveal the failure mechanism and form the scientific research methods for the unloading rheological characteristics and failure mechanism of hard fractured rock mass based on anisotropy at high temperatures.

大型水电站地下洞室的劈裂破坏是硬脆性岩体在真三维复杂条件下因洞室开挖卸荷形成的一种特殊的工程破坏现象，是影响地下洞室施工开挖安全和长期运行稳定的重要因素。由于深部裂隙岩体往往伴随高地温环境，目前很难分清哪部分变形是由开挖卸荷引起的，哪部分变形是由温度变化引起的，对深部洞室开挖卸荷诱发的劈裂破坏机理也尚未认识清楚。为了研究这一科学问题，本项目将以洞壁出现劈裂破坏现象的齐热哈塔尔水电站深部地下高温洞室作为研究背景工程，拟通过模型试验、理论研究和数值分析，精细模拟高温条件下深部洞室裂隙硬岩开挖卸荷流变的破坏条件与形成过程，探索裂隙硬岩高温卸荷流变应力条件及变形规律，探明高温卸荷流变的损伤演化特征与破坏模式，揭示深部洞室裂隙硬岩高温卸荷流变破坏机理，形成研究深部裂隙硬岩高温高应力卸荷各向异性损伤流变特性及破坏机理的系统研究方法。

大型水电站地下洞室的劈裂破坏是硬脆性岩体在真三维复杂条件下因洞室开挖卸荷形成的一种特殊的工程破坏现象，是影响地下洞室施工开挖安全和长期运行稳定的重要因素。由于深部岩体往往伴随高地温环境，目前很难分清哪部分变形是由开挖卸荷引起的，哪部分变形是由温度变化引起的，对深部高温洞室开挖卸荷诱发的劈裂破坏机理也尚未认识清楚。为了研究这一科学问题，本项目将以洞壁出现劈裂破坏现象的齐热哈塔尔水电站深部地下高温洞室作为研究背景工程，以坝基花岗岩体为研究对象，通过现场检测、试验分析、理论分析和数值分析等手段，系统研究深埋硬岩高温高应力卸荷流变特性及破坏机理。基于试验结果，以弹塑性力学、热力学和损伤力学理论为指导，分析花岗岩在热力耦合作用下的损伤演化过程，构建硬脆性岩石热黏弹塑性蠕变损伤模型并进行数值分析，将数值分析结果与试验测试结果进行对比，共同揭示深埋硬岩高温高应力卸荷流变规律和破坏机理。