流固耦合作用下浅埋近接双线盾构隧道开挖扰动分析

Disturbance Analysis of Shallow Buried and Small Interval Shield Tunnel Excavation Based on Fluid-solid Coupling

依托广佛环线沙堤盾构隧道工程,通过FLAC3D软件的流固耦合模块,分析了富水地层浅埋近接双线盾构隧道开挖的应力场、渗流场和位移场的扰动行为。研究结果表明:屈服接近度可以作为从应力状态角度分析隧道开挖扰动行为的定量指标;随着横向净距的增大,左、右线隧道开挖对地层渗流场的扰动趋向于单线隧道开挖对渗流场的扰动特征,隧道施工引起的地表沉降槽曲线逐渐由深"V型"趋向于"W型"分布;当横向净距大于1.5 D时,左、右线隧道开挖引起地层扰动的叠加效应较小。

Based on the embankment shield tunnel of Guangfo loop line, the disturbance behavior of stress field, seepage field and displacement field of shallow buried and small interval shield tunnel in water-rich stratum is analyzed by means of FLAC3D fluid solid coupling calculation module. The results indicate that yield approach index can be used as a quantitative index to analyze the disturbance behavior of tunnel excavation from the angle of stress state. With the increase of transverse spacing, the disturbance of seepage field caused by double-line tunnel excavation tends to be the disturbance characteristic of single line excavation on seepage field, the settlement curve shape caused by double-line tunnel construction changes from V-shape into W-shape. When the transverse spacing is greater than 1.5D, the superposition effect of formation disturbance caused by double-line tunnel excavation is small.