隧道穿越富水断层围岩稳定性流固耦合研究  

Study on Stability of Surrounding Rock Due to Tunnel Passing Across Water-bearing Fault Utilizing Fluid-mechanical Coupling

作　　者：穆兰[1] 胡宇庭[1] 

机构地区：[1]石家庄铁路职业技术学院,河北石家庄050041

出　　处：《公路工程》2017年第4期108-113,共6页Highway Engineering

基　　金：国家自然科学基金项目(51178399)

摘　　要：围岩稳定性和结构安全一直是富水区山岭隧道修建过程中的热点问题,长期受到学术界和工程界的关注。以罗汉坡公路隧道穿越F5富水断层为依托,建立三维流固耦合数值力学模型,模拟施工全过程,研究围岩变形特性、力学响应、渗流场、能量集聚,以及衬砌结构位移。研究结果表明:掌子面前方围岩出现高水压积聚现象,应进行超前1D(D为隧道跨度)钻孔排水,降低掌子面前面水压集聚程度;掌子面前方有效影响挤出变形的距离为0.5D。由于断层及其前后围岩刚度差异,衬砌沿纵向发生不均匀变形,断层前、后10 m范围内衬砌应加大配筋,防止结构压剪破坏,提高衬砌整体稳定性及降低运营阶段风险。研究成果直接指导罗汉坡隧道F4断层的施工,也可为今后富水地层类似隧道及地下工程设计、施工提供参考和借鉴。To date, attention has been typically paid on stability of surrounding rock and struc- tural safety when the tunnel is embedded in the water-bearing fault from viewpoint of academy and engi- neering. By taking Luohanpo highway tunnel passing across F5 water-bearing fault as an instance, three dimensional coupled fluid-mechanical modelling was performed to investigate the entire procedure of con- struction, in an effort to clarify displacement response, mechanical characteristics, and seepage field as well as energy concentration, together with structural deformation. Inspection of results reveals that high- water pressure appears ahead of working face, thus advanced drainage shall be recommended to release water-pressure concentration extent using drilling methodology with length of 1D （ D equals to span of tun- nel） . The affected length ahead working face pertaining to extrusion deformation reaches 0.5D. Due to the stiff deference between fault and its surrounding rock, the inhomogeneous deformation of lining ap- pears along the tunnel-axis direction. The lining shall be reinforced ahead and after the boundary of fault 1.3D to prevent compressive-shear failure of lining, capable of enhancing the stability of tunnel and reducing the risk during the operation. The research result can directly guide construction of Luohanpo tunnel passing across F4 fault, but also supply the reference for construction and design of similar tunnel and underground engineering in water-bearing stratum in future.

关 键 词：隧道 富水断层 渗流场 能量集聚 流固耦合 

分 类 号：U452.2[建筑科学—桥梁与隧道工程]