盾构下穿复杂区间隧道数值模拟及施工关键技术研究

在城市地铁网的建设过程中,经常出现盾构隧道下穿建筑物、小半径曲线及浅覆土等工程施工重难点。为确保盾构机在推进过程中的不间断运行和沿线风险源的安全,结合天津地铁1号线双林站—李楼站盾构区间的施工实践,针对风险源的特点,提出了盾构始发与接收端头加固方案、区间隧道盾构掘进施工方案等详细措施,并运用MIDAS/GTS有限元软件建立了盾构区间—土体—既有上地站的协同作用整体模型,模拟了盾构区间施工过程,得出协同作用整体模型下既有上地站站房及其独立基础应力及位移变化规律,保证盾构隧道下穿过程中各项风险源的安全。研究成果可为今后类似工程提供借鉴和参考。

Numerical Simulation of Shield Underneath Pass Through Complex Interval Tunnel and Research on Key Construction Techniques

Shield tunnel underneath pass through buildings,small radius curve,shallow overburden soil as well as other project construction keys and difficulties are often encountered during the construction of urban subway network.The construction practice of Tianjin metro line 1 Shuanglin station-Lilou station shield interval is combined in order to ensure continuous operation of shield construction machine during advancing and the safety of risk sources along the route.The following detailed measures are proposed aiming at the characteristics of risk sources,such as shield originating and receiving end reinforcement scheme,interval shield tunneling construction scheme,etc.The MIDAS/GTS finite element software is used to establish shield interval-soil mass-existing Shangdi station synergy integral model.The construction process of shield intervals is simulated.The existing Shangdi station room,its independent foundation stress and displacement change laws under the synergy integral model are obtained,thereby ensuring the safety of various silk sources during shield tunnel downward penetration.research results can provide reference for similar projects in the future.