深埋超长输水隧洞钻爆法开挖段软弱围岩工程灾害的形成机制及防控研究

In the next decade, a great number of deep-buried, super-long water conveyance tunnels will be constructed in our country. In the sections crossing weak surrounding rock, the sources of disaster increase considerably, including the high in-situ stress, joints and fractures, mudstone minerals, unknown groundwater bodies, karsts and structural fractured zones. These factors significantly elevate the risk of geologic hazards, e.g., the collapses, water inrush and mud outburst. Drilling-and-blasting excavation method must be used under these circumstances and the existing theories and technologies are not fully applicable anymore, thus, the prevention and mitigation of geologic hazards are the key scientific issues remain to be solved. Relying on one water transfer project in Northwest China, this project is proposed with the following tasks and objectives: first, to accurately detect the sources of disasters by developing the tunnel face geological forecast technology and equipment through combining the logging-while-drilling, geological radar and seismic methods, and by developing the rock mass structural detection technology and equipment based on the borehole TV and borehole radar; second, to investigate the conditions under which the disaster sources can transform into disasters and to elucidate the mechanisms underlying the evolution and occurrence of hazards by conducting field geological survey, geophysical exploration, rock mechanics and physical model tests; after that, the Hydro-Mechanical-Chemical coupled 3D continuum-discontinuum FDEM model will be proposed, based on which the calculation program can be developed and the new numerical method for the prevention and mitigation of geologic hazards can be established; finally, we aim to propose the theory for the quantitative calculation of risk, to establish the artificial intelligence methods as well as the expert system, and to develop and improve the theory for the prevention and mitigation of geologic hazards in weak surrounding rocks during tunneling.

未来十年，我国将进入深埋超长输水隧洞建设的高峰期。此类隧洞软弱围岩段高地应力、节理裂隙、泥岩矿物、不明水体、岩溶和构造破碎带等灾害源明显增多，塌方、突水和涌泥等工程灾害风险显著加大，需钻爆法开挖才能通过，现有理论和技术已不能完全适用，工程灾害防控是亟待解决的关键科技难题。本项目依托西北某调水项目，首先研发随钻+地质雷达+地震法探测相结合的掌子面超前地质预报技术及装备、钻孔摄像和孔内雷达无缝融合的岩体结构探测技术及装备，以准确查明灾害源；其次，开展现场地质调查、物探、岩石力学和物理模型试验，研究灾害源转化为灾害的条件，揭示工程灾害形成和突发的机制；然后，提出渗流-应力-化学耦合条件下三维连续-非连续FDEM数值理论模型，开发计算程序，建立工程灾害防控的新型数值分析方法；最后，提出工程灾害风险的定量计算理论，建立灾害防控的人工智能方法并开发专家系统，发展完善隧洞软弱围岩工程灾害的防控理论。

我国正处于深长输水隧洞建设的高峰期。此类隧洞地处地质运动剧烈区，泥岩、水体、岩溶和构造破碎带等灾源多，塌方、突水涌泥等灾害风险大，工程灾害防控是亟待解决的关键科技难题。本项目依托系列在建水利水电、高速交通等领域的钻爆法隧洞工程，对灾害源探测、灾害演化机理、灾害防控三个方面的基础理论和技术开展了深入研究，取得了如下创新成果： .一、实现了隧洞作业面智能地质感知和近场围岩地质透明化。提出了孔内光学、电磁、声学等多源探测信息的无缝融合理论算法，研制了炮孔随钻探测仪、钻孔电视-雷达-超声探测成套技术装备，攻克了信息自动化获取、多手段协同和立体成像难题。.二、实现了不停工条件下隧洞中远场地质灾害源的精准探测。首创掌子面爆破/电火花为震源的地震法超前地质探测技术装备，提出了远场地震法与中场电磁法超前探测信息的耦合解译方法，解决了隧洞掌子面中远场超前地质探测耗时、昂贵、精度低、干扰施工等难题。.三、实现了隧洞工程灾害形成条件和突发机理的定量化揭示。构建了基于现场试验的深长输水隧洞快速工程地质评价方法，探索出了大型真三维物理模型试验技术，研发了三维连续-非连续数值模型和计算程序，定量化确定了灾害源转化为灾害的条件，揭示了工程灾害的演化机制。.四、实现了隧洞重大地质灾害源的风险规避和施工安全决策。提出了深长隧洞重大地质灾害源风险评估系列数学模型，开发了基于大数据、物联网、人工智能和云计算的隧洞施工风险管控、智能决策平台，解决了隧洞施工风险评估、灾害预警依赖经验和智能化程度低的难题。.项目负责人主持获得2021年湖北省科技进步一等奖，获国务院政府特殊津贴，当选ISRM DDA Commission主席；项目组出版专著3部，主编行业规范3部，发表SCI论文61篇，授权中外发明专利31件；培养国家海外优青和青托人才各1名、研究生42名，3人入选全球前2%顶尖科学家榜单；项目成果成功应用于数百公里隧洞工程的建设，破解了钻爆法隧洞施工受艰险地质条件制约的瓶颈问题，经济和社会效益显著，推动了行业科技水平的进步。