超小净距盾构隧道施工对既有隧道变形分析

Analysis of deformation of existing tunnelsby ultra-small clearance shield tunnel construction

近年随着我国双线地铁建设快速发展过程中,由于周围的地质情况和城市管线、建筑基础的布局等原因,常常会导致双线隧道间距过小。双线盾构开挖过程中两边隧道难免会产生相互影响。因此,研究双线近距盾构隧道开挖对邻近隧道内力和变形的影响,具有非常重要的实际意义。根据雄安新区至北京大兴国际机场快线工程金融岛站—第五组团站盾构区间工程实例,使用ABAQUS进行建模,模拟超小净距盾构开挖过程中双线隧道的位移变形。研究结果表明:在竖直方向,隧道位移分布均匀,隧道下部部分位移较大;横向位移隧道两端较小,中部较大,根据变形情况讨论该工程过程中可能产生的影响安全性的问题及应对措施。

In recent years,with the rapid development of China’s two-line underground construction process,due to the surrounding geological conditions and the layout of urban pipelines,building foundations and other reasons,often leads to the two-line tunnel spacing is too small.It is inevitable that the tunnels on both sides of the double line shield excavation process will have mutual influence.Therefore,it is of great practical significance to study the influence of double-line proximity shield tunnel excavation on the internal force and deformation of the neighbouring tunnels.This paper uses ABAQUS to model the displacement and deformation of the two-lane tunnel during the excavation of the ultra-small clearance shield tunnel according to the example of the shield interval project from Financial Island Station to Fifth Cluster Station of the Xiongan New Area to Beijing Daxing International Airport Express Project.The results show that:in the vertical direction,the displacement of the tunnel is uniformly distributed,and the displacement of the lower part of the tunnel is larger;the lateral displacement of the tunnel is smaller at both ends and larger in the middle,according to the deformation situation,we discuss the possible problems affecting the safety of the project and the countermeasures,so as to provide a reference for the construction of similar projects.