地铁车站近接正交下穿既有地铁隧道的变形分析

北京地铁五号线崇文门车站正交下穿既有地铁二号线崇文门站东端喇叭口式过渡段区间,两者之间的净距仅为1.98m.该地铁车站施工采用全断面注浆条件下的柱洞法.文章以此工程背景为研究对象,采用3D-σ三维数值分析软件,建立地铁车站-已有地铁隧道的三维有限元模型,计算分析隧道动态施工时地层以及既有地铁隧道沉降变形发展规律,对比分...

Deformation Analysis of the Subway Station Perpendicularly Under-passing an Existing Subway Tunnel with a Small Clear Distance

Chongwenmen Station on Beijing Metro Line 5 perpendicularly under-passes east end trumpet section of Chongwenmen Station on Metro line 2 with a clear distance of only 1.98 meters.The construction method of "column-heading" was adopted with full-face grouting.Taking this project as the background,a three-dimensional FEM model was established by the software of 3D-σ,with which the developing regulation of settlements and deformations of strata and the existing tunnel during construction were studied and the influence of grouting on deformations of ground surface and existing tunnel were analyzed.Results indicatd: 1.The settlement development trend of the existing tunnel base and ground surface was basically synchronous even though the former was a little bit larger than that of the latter,which showed that the existing structure possessed the bearing capacity for the above soil;2.The settlements of ground surface and existing tunnel during construction were mainly caused by the support construction of middle cell and side cell,and the influence of subsequent construction was limited;3.The deformations of ground surface and existing tunnel can be reduced considerably by grouting.Research results of the paper can be taken for reference by the similar projects in the future.