超前开挖距离对大跨度小净距隧道稳定性影响的有限元分析  

Finite element analysis on the influence of advanced excavation distance to tunnel stability of large-span tunnel with small interval

作　　者：石宵爽[1] 曾祥国[1] 赵师平[1] 刘永杰[1] 王清远[1] 

机构地区：[1]四川大学建筑与环境学院,四川成都610065

出　　处：《四川建筑科学研究》2008年第2期132-137,共6页Sichuan Building Science

基　　金：教育部科学技术研究重大项目(305013);四川大学"985"科技创新平台引进人才项目

摘　　要：小净距双孔隧道开挖过程中两孔之间的相互耦合作用是施工过程十分关心的问题,其相互影响与围岩类别、隧道跨度、隧道间距、开挖和支护方式有关。利用ANSYS有限元软件对重庆花土岗隧道开挖过程进行了数值模拟,计算了在两孔开挖方向上相距分别为10 m,30 m,50 m时,开挖对地表沉降、围岩变形和围岩应力的影响。研究表明,先行洞超前开挖距离的增大有利于隧道围岩的稳定,对本隧道采用超前开挖30 m的施工方案是可行的;基于ANSYS有限元对开挖过程的数值分析结果,指出小净距双孔隧道施工过程中重点监控与关注的位置。本文的分析方法和计算结果对小净距隧道设计、施工具有一定的参考价值。The coupling effect of two roadways is very important in small interval tunnel excavation, and it is related to the grade of surrounding rocks, span and interval of the tunnels, methods of excavation and supporting. With the engineering background of Huatugang tunnel in Chongqing, the FE software ANSYS is adopted to simulate the excavation of tunnel, and the influences of excavation to the ground surface settlement, deformation and stress of the surrounding rocks under ten, thirty and fifty advanced excavation distance are studied respectively. The results show that increase of advanced excavation distance is advantage to the stability of surrounding rocks, and it is feasible for this tunnel to be excavated by thirty advanced excavation distance, and the key positions of measurement during excavation are proposed. The analysis method and conclusion in this paper may provide some references for the design and construction of small interval tunnels.

关 键 词：小净距隧道 超前开挖 围岩稳定性 有限元数值方法 单元生死 

分 类 号：TU28[建筑科学—建筑设计及理论]