盾构隧道施工对邻近地下管线影响分析

Analysis of the Effects on the Adjacent Underground Pipelines by Shield Tunneling Construction

采用弹性地基梁理论及管线—土—盾构相互耦合的FLAC3D数值方法,结合实测结果,分析深圳地铁益田站至香蜜湖站区间盾构隧道施工对3 m直径电缆管线的影响。分析表明:盾构隧道左线施工后,管线变形符合Gauss分布,右线施工后变形不再符合Gauss分布,主要变形段内的变形增大很多,最大变形点位置也发生改变;右线施工后,管线的纵向受力得到改善;管线及地表变形不超过规定值,最大应力不超过容许应力,说明该段隧道施工没有影响电缆管线的运行安全。与实测结果的比较表明:弹性地基梁法可用于估算管线的最大变形,FLAC3D数值方法可较准确模拟盾构隧道对管线的影响。

The effects on the 3 m diameter cable pipelines induced by shield tunneling construction from Yitian to Xiangmihu interval of Shenzhen Metro were analyzed by adopting elastic foundation beam theory and pipeline-soil-shield coupling FLAC3D numerical simulation method according to field tested results. Analysis shows that the deformation of the pipeline matches the Gaussian distribution after the left tunneling, but it no longer matches the Gaussian distribution after constructing the right tunneling. The deformation of the main interval increases and the location of the maximum deformation has been changed. The longitudinal mechanical force of the pipelines has been improved after the right tunneling construction. The deformation of the pipelines and the soil surface is under the allowable value, and the maximum stress is under the allowable stress. It indicates that the tunneling construction of this interval does not endanger the safety operation of the cable pipelines. Compared with field test results, the elastic foundation beam method can be used to evaluate the maximum deformation of pipelines, and the FLAC3D numerical method can accurately simulate the impact on the pipelines by shield tunneling.