大断面深埋隧道穿越富水断层灾变研究  

Study on disaster of large cross-section deep tunnel passing water-rich fault

作　　者：舒磊[1,2,3] 何本国[1,2] 龚伦[1,2] 王海彦[1,2] 

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,四川成都610031 [2]西南交通大学土木工程学院,四川成都610031 [3]中铁工程设计咨询集团有限公司,北京100055

出　　处：《自然灾害学报》2013年第4期193-200,共8页Journal of Natural Disasters

基　　金：国家自然科学基金资助项目(51178399);中央高校基本科研业务费专项资金资助(SWJTU11ZT33)

摘　　要：大断面深埋隧道穿越富水断层施工具有很大风险,一直是工程界的关键科学问题。通过现场试验和三维各向异性非线性流固耦合模型,研究了富水断层隧道支护体系受力特征、空隙水压、能量积聚、变形特性和力学响应。斗篷山隧道F3断层掌子面水压现场实测为1.50 MPa,排水后衬砌外水压力降至0.1 MPa,隧道高水压问题主要集中在掌子面开挖。拱腰锚杆受力较小,建议取消拱部系统锚杆,只打设拱部锁脚锚杆,及早封闭成环;围岩压力以拱部为主,掌子面前方出现高水压积聚,应超前排水释能降压。待挖核心土能量先增大再减小,峰值位置为失稳潜在区域,断层超前预加固有效距离为一倍洞跨。二次衬砌变形范围为地层变化处前、后10 m,应对该影响地层加固处理,加大此范围衬砌配筋。研究成果可为富水断层隧道及类似工程的修建提供参考。The construction of large cross-section deep tunnel through water-rich fault is of high risks, and has been a key scientific problem in the engineering field. In this study, the mechanical characteristics of the support system, pore water pressure, energy accumulation, deformation characteristics and mechanical response for tunnels through water-rich fault were investigated using field tests and nonlinear anisotropie fluid-solid coupling model. Research results show that, measured water pressure in F3 fault of Doupeng Mountain tunnel is 1.50 MPa. After drainage, the maximum water head is dropped to 0.1 MPa. Therefore, high water pressure appears mainly during working face excavation. Axial force of bolts at arch is small. Thus, it is suggested that systematic bolts at arch be cancelled, and only feet-lock bolt be installed. This could reduce the sealing time of primary supports. Pressures of the surrounding rock are larger at arch than at side walls. Pore-water pressure accumulation occurs in front of the working face. Therefore, drainage should be carried out in advance to release the stored energy. Energy distribution in front of the working face first increases, and then decreases, and peak values indicated the potential instable area. The effective distance for pre-reinforcement is one span of the tunnel. The changing range of the lining is 10 meters back and forth of the interface of the rock and the fault. Accordingly, reinforcement should be performed during construction. The research findings can give a reference to the construction of tunnels through water-richfaults and similar engineering projects.

关 键 词：富水断层 大断面隧道 空隙水压 能量积聚 支护体系 现场试验 

分 类 号：U25[交通运输工程—道路与铁道工程]