下穿大堤盾构隧道引起的沉降分析

Analysis on Embankment Settlement Caused by Undercrossing of Shield Tunneling

下穿大堤盾构隧道将引起地层变形与地表沉降,以南京市纬三路过江隧道工程为背景,通过对比现场监测和理论计算结果,并采用数值模拟方法,研究了盾构下穿防洪堤引起的地层变形和地表沉降规律。结果表明,除管片安装完成初期考虑椭圆化地层变形得出的理论解外,实测地表沉降槽要深于两种理论结果。同时对比了实测和数值模拟计算得出的堤顶处的历时地表沉降曲线,分析结果验证了数值模拟方法在预测盾构掘进过程中地表沉降的可行性。

The surface subsidence and strata deformation will occur when shield tunnel under crosses an embankment. In this paper based on the Weisanlu River-crossing Tunnel Project in Nanjing, and a study is conducted by comparing the results of field monitoring and theoretical calculations, and by means of numerical simulations to analyze strata deformation and ground subsidence of flood embankment caused by under-crossing of shield tunneling. The results show that the measured surface settlement trough is deeper than two kinds of theoretical results except the theoretical solution considered elliptical deformation after the completion of installing segments. Meanwhile, the curve of surface settlement derived by measurement and numerical simulation are compared at the top of the embankment, and the analysis results show that the numerical simulation method is feasible to predict the surface subsidence in the process of shield tunneling.