盾构隧道下穿高铁站影响规律与控制措施:以天津地铁四号线下穿天津西站为例

Influence Law and Control Measures of Shield Tunnel UndercrossingHigh Speed Railway Station: Taking the Tianjin Metro Line 4 as anExample of Undercrossing Tianjin West Station

已有研究对下穿高铁车站工程的变形规律以及施工措施研究并不充分。以天津地铁四号线北段下穿天津西站工程为背景,利用大型有限元软件,对下穿工程进行了数值模拟,验证了各个施工措施的有效性,对桩基变形进行了分析。研究表明,盾周空隙充填注浆施工具备很好的减小地层沉降的效果;底板加厚可以在一定程度上减小盾构下穿结构的竖向变形,且站房本身的框架结构在一定程度上削减了盾构下穿带来的影响;掌子面压力越大,桩基上部远离盾构的横向位移越大,向着盾构掘进方向的位移越大;注浆压力越大,桩基横向变形、纵向变形越小;在盾构侧穿的过程中,桩基顶端在不断沉降,底端隆起幅度较小。研究成果可为盾构隧道下穿既有地下结构等类似工程提供借鉴及参考。

There is insufficient research on the deformation laws and construction measures of the underpass high-speed railway station project.Taking the Tianjin Metro Line 4 North Section undercrossing Tianjin West Station project as the background,and using large-scale finite element software to conduct numerical simulation of the undercrossing project,the effectiveness of various construction measures was verifyied,and the deformation of the pile foundation was analyzed.Results show that the filling and grouting construction of the gaps around the shield and the secondary grouting construction have a good effect on reducing ground settlement.Thickening the bottom plate can reduce the vertical deformation of the shield tunneling structure to a certain extent.and the frame structure of the station building itself reduces the impact of shield tunneling to a certain extent.The greater the pressure on the palm face,the greater the lateral displacement of the upper part of the pile foundation away from the shield tunneling,and the greater the displacement towards the direction of the shield tunneling.The greater the grouting pressure,the smaller the lateral and longitudinal deformation of the pile foundation.During the process of shield tunneling,the top of the pile foundation is constantly sinking,while the bottom is slightly raised.The research results can provide reference and reference for similar projects such as shield tunneling through existing underground structures.