深埋隧洞滞后型岩爆的围岩时效变形诱发机理研究

In recent years, more and more long, large and deeply buried tunnels being constructed have brought about many deep rock mechanics problems, of which the most prominent rockburst, has become a technical bottleneck in the future deep underground engineering. In this project, the key scientific issue, viz., time-dependent deformation of the surrounding rockmass leads to delayed rockburst in deep tunnel is to be concentrated considering the time-dependent deformation characteristics of the surrounding rockmass in deep buried tunnels, adopting multi-disciplinary methods such as rheological mechanics, damage mechanics and information science, and performing triaxial creep and AE testing and field microseismic monitoring, to study the crack precursor and its temporal and spatial evolution during rock creep, to analyze creep deformation, associated damage evolution and creep rate evolution characteristics during unloading of deep rock mass, to establish a high-stressed creep damage model, to construct a link between the microseismic events and physico-mechanical parameters, to perform a series of numerical simulations on the rheological instability of surrounding rockmass in deep buried tunnels under different partial stresses, and to reveal the time-dependent deformation induced delayed rockburst mechanism of surrounding rockmass in deep tunnels. It is expected to offer theoretical and practical instructions for the instability control and long-term stability prediction of deep buried tunnels.

近年来有越来越多的深埋长大隧洞进入施工期，带来许多深部岩石力学问题，其中以岩爆最为突出，已成为我国未来深部地下工程中的一大技术瓶颈问题。本项目以深埋隧洞围岩的时效变形诱发滞后型岩爆这一关键科学问题为核心，基于流变力学、损伤力学、信息科学等多学科交叉的研究方法，围绕深埋隧洞围岩的时效变形特性，进行声发射辅助岩石三轴蠕变实验和现场微破裂监测实践，研究深埋隧洞围岩在蠕变过程中的微破裂前兆及其时空演化规律，根据卸荷蠕变变形损伤演化规律及蠕变率随时间的发展阶段特征，构建高应力作用下岩体蠕变损伤模型，建立微震活动信息与物理、力学参数变化之间的联系，应用大规模数值分析方法进行不同偏应力作用下深埋隧洞围岩的流变失稳研究，揭示深埋隧洞滞后型岩爆的围岩时效变形诱发机理，为寻求深埋隧洞变形失稳控制及长期稳定性的预测提供理论和应用基础。

本项目以深埋隧洞围岩的时效变形诱发滞后型岩爆这一关键科学问题为核心，基于流变力学、损伤力学、信息科学等多学科交叉的研究方法，探索深埋隧洞滞后型岩爆的诱发机理。通过卸荷蠕变变形损伤演化规律及蠕变率随时间的发展阶段特征研究，建立了反映材料流变特性的细观本构关系和细观损伤演化方程。总结了锦屏二级引水隧洞的岩爆发生特征，系统研究了影响滞后型岩爆发生的条件：内部因素（岩石材料的蠕变效应、非均匀性）和外部效应（湿度扩散、动力作用）。根据岩体破裂过程中的3S机理，建立微震监测技术的岩爆临界预警机制。本项目成果为深埋隧洞变形失稳控制及长期稳定性的预测提供理论和应用基础。.在本项目的资助下，课题组出版专著1部，申请发明专利3项，获得省部级科技进步二等奖1项，省部级学术成果三等奖1项。在国际刊物上发表论文8篇，国内核心刊物上发表论文5篇。其中，SCI收录论文4篇，EI收录论文8篇，接受未刊出论文1篇（EI刊源）。培养博士研究生3人，硕士研究生7人。参加国际学术会议3人次。