基坑开挖对下卧地铁隧道的影响研究

Effect of foundation pit excavation on underlying metro tunnels

对地铁盾构隧道上方进行基坑开挖的工程实例进行了三维有限元数值分析,得到了基坑开挖引起的隧道纵向隆起值,将有限元计算结果与现场实测数据比较,表明有限元计算结果与现场实测数据基本吻合,通过对有限元计算结果与现场实测数据的研究分析,得到了基坑开挖引起下卧隧道纵向隆起的规律,如隧道纵向隆起曲线基本呈高斯正态分布曲线,隧道纵向隆起的范围约为基坑沿隧道纵向开挖长度的2～3倍等。

3D FEM was used to analyze the effect of the foundation pit excavation on the underlying metro tunnels with regard to a real construction item.The longitudinal heave of the tunnels was obtained.Compared the FEM results with the monitoring data,it could be found that the FEM results were fundamentally close to the monitoring data.After the analysis of the two results,some conclusions about the longitudinal heave of the tunnels with foundation pit excavation can be drawn,the longitudinal heave curve of the tunnels is nearly a normal distribution curve,and the longitudinal range of the runnel heave is about 2-3 times the foundation excavation length along the tunnel axis.