隧道盾构施工对既有桥梁影响的数值分析

Numerical Analysis of the Influence of Shield Tunneling on Existing Bridges

本文以合肥地铁2号线下穿五里墩立交桥工程为背景,通过有限元分析软件FLAC3D来模拟双线隧道先后盾构滞后距离的远近对侧穿桥墩桩基的影响,并结合实时监测数据进行对比分析桩基竖向沉降和水平侧移。综合分析表明,在先后隧道开挖面滞后距离60 m时,桩基竖向最大沉降为2.97 mm,水平最大侧移是0.75 mm;双线隧道掌子面滞后距离在0~60 m内,对桩基的横向变形影响不大,最大侧向变形为0.76 mm。

In this paper, based on a shield tunnel of Metro line 2 in Hefei under-passing the viaduct of Wulidun. The finite element analysis software FLAC3D was used to simulate the influence of the lagging distance between two tunnels on the pile foundation. And the vertical settlement and horizontal lateral displacement of the pile foundation are compared with the real-time monitoring data. The comprehensive analysis shows that the maximum vertical settlement of pile foundation is 2.97mm and the horizontal maximum lateral displacement is 0.75 mm when the tunnel excavation face is 60m behind. The lagging distance of the two-line tunnel face is 0 ～ 60 m, which has little influence on the lateral deformation of pile foundation, and the maximum lateral deformation is 0.76 mm.