管幕-结构法群管顶进对车站站场站台及股道沉降影响研究

为揭示管幕施工中群管顶进对站台和股道的影响规律，以迎泽大街下穿太原市火车站通道工程暗挖段管幕-结构法施工为例，采用数值计算对钢管不同顶进次序对地表沉降影响进行分析，推荐先下后上的群管顶进次序；采用数值计算和现场监测相结合的手段，对群管顶进过程中站台和股道沉降变化特征进行研究。研究结论如下： 1）群管顶进对地层沉降变形影响是一个多次叠加效应，具有应力路径相关性，顶进过程中地表横向沉降曲线形态处于动态变化之中，最终呈现出类似Peck横向沉降槽的曲线形态； 2）群管顶进结束后地表沉降横向槽宽度约为50 m，位于管幕底部两侧约45°地层滑移角范围之内； 3）现场监测结果表明管幕-结构工法有良好的地层变位控制效果，在多次顶进扰动影响下，站台和股道沉降、轨道高低及水平变形皆在控制范围之内。

Influence of Multi pipe Jacking of Pipe Curtain Structure Method on Settlement of Platform and Track of Railway Station

The influence of multi pipe jacking on platform and station track is studied based on the pipe curtain structure method (PSM) construction of mined section of Yingze Street crossing underneath Taiyuan Railway Station. Firstly, the influence of steel pipe jacking sequence on the surface settlement is analyzed by numerical calculation, and the down top jacking sequence is recommended. And then the settlement variation characteristics of platform and track are studied by numerical calculation and field monitoring. The study results show that: (1) The effect of multi pipe jacking on stratum settlement is a multiple superposition effect, which is stress dependent; during jacking process, the shape of surface settlement curve is changing dynamically, and ultimately, the final transverse settlement groove similar to Peck curve shape is formed. (2) The width of transverse groove of surface settlement is about 50 m after multi pipe jacking, which locates in the slip angle range of almost 45°of strata on both sides of the bottom of the pipe curtain. (3) The field monitoring results show that the PSM has a good effect on stratum displacement control; and the platform settlement, track irregularity and horizontal deformation are all within the control range under the influence of multiple jacking disturbances.