循环侵水作用下库坝基岩细观损伤与流变特性关联机制研究

The abandoned open pit will be converted into a tailings pond or a reservoir for reuse, which is in line with new and old kinetic energy conversion and green development current policies of China. In the process of reuse, the safety of the slope of the pit in the process of precipitation and inundation cyclic cannot be ignored. Based on the laboratory test and the combination of theoretical analysis and numerical simulation, Study on the correlation mechanism between meso-damage and rheological properties of the dam bedrock which influence by inundation cyclic. Firstly, the meso-damage evolution law of rock samples which different inundation pressures and different cycle times was studied by CT scanning, EDS, SEM and other experimental methods, and the meso-damage variables were constructed. Secondly, the rheological experiment of inrush rock is carried out relying on the self-developed inundation cyclic rock rheological synchronous system, and the rheological model identification is carried out to Study on rock mechanics deterioration characteristics considering time effect under inundation cyclic. Finally, The inundation cyclic rock’s macro-damage mechanical property which based on meso-damage combine equivalent strain principle is constructed. Based on this, the rheological damage model of inundation cyclic rock is proposed. The secondary development of numerical simulation software of rheological constitutive relation is carried out to obtain the rheological simulation model of inundation cyclic rock considering the meso-damage. The research results have important scientific significance for the study of the stability of inundation cyclic slope.

废弃的露天矿坑转为尾矿库或生态水库再利用，符合我国当前新旧动能转化和绿色发展政策。而再利用过程中，矿坑边坡由降水、循环侵水所引发的安全问题不容忽视。本项目拟以室内试验测试为基础，采用理论分析与数值模拟相结合的方法，研究库坝基岩在循环侵水作用下的细观损伤与流变特性关联机制。首先通过CT扫描、能谱电镜扫描等试验手段，研究岩石在不同侵水压力、循环次数下的细观损伤演化规律；其次依托自主研发的岩石循环侵水与流变同步配件，进行侵水岩石流变同步试验，根据流变曲线辨识流变模型，研究循环侵水作用下考虑时间效应的岩石力学劣化特性；最后基于等效应变原理建立循环侵水岩石宏观力学性质的细观损伤表征方法，提出循环侵水作用下的流变损伤本构关系，并进行数值模拟程序二次开发得到考虑细观损伤的岩石流变数值模拟模型；研究成果对循环侵水库坝岩石边坡的稳定性研究具有重要的科学意义。

循环侵水作用导致边坡岩体宏观强度弱化和细观结构损伤，极易引发岩体崩塌或边坡划移等滑地质灾害。针对循环侵水作用对边坡岩体的影响，采用室内试验、理论分析与数值模拟相结合的方法，围绕循环侵水作用下岩石的细观损伤演化规律、循环侵水作用下岩石流变力学劣化特性和考虑宏细观内在联系的流变本构关系等3个核心问题展开研究。. 首先，根据岩石扫描电镜和CT试验结果，分析不同循环侵水作用下岩石内部裂隙及空洞等缺陷的演化规律¬，定量分析岩石宏观破坏的本质原因；基于分形理论和损伤力学理论实现岩石细观结构损伤的定量表征，构建基于分形维数和孔隙结构参数的损伤变量。. 其次，开展单向加载和三轴加载的岩石流变试验，研究循环侵水过程中岩石流变变形规律和变形特性变化，分析岩石长期强度与循环侵水次数的定量关系，从流变变形、流变时间和长期强度等角度分析了循环侵水与上覆荷载耦合作用下岩石的流变力学特性劣化规律。. 最后，耦合岩石的宏细观损伤变量，建立循环侵水作用下岩石宏观力学性质的细观损伤表征，由此构建循环侵水作用下岩石流变损伤本构模型；对循环侵水-上覆荷载耦合损伤演化过程进行研究，并建立了考虑上覆荷载-循环侵水耦合作用的流变损伤模型。.研究成果为揭示循环侵水作用下岩石宏观强度弱化和细观结构损伤，分析循环侵水作用导致的岩石损伤演化规律及本构关系，为边坡稳定性分析和加固提供指导。.