下穿既有铁路管涵顶进施工的变形分析与安全控制研究

Study on the Analysis of Deformation and Safety Control About Jacking Construction of Pipe Culverts Underneath Existing Railway

管涵道下穿既有铁路施工时势必会引起周围地层移动,影响铁路正常运营。针对不同土质和不同管涵的埋深建立三维数值模型。结合中缅管道昭通支线天然气管涵工程下穿沪昆铁路工程为研究对象,通过MIDAS GTS NX数值模拟软件对施工过程进行模拟分析,利用JMDL-62XX系列智能数码静力水准仪实时监控施工期间路基沉降。重点研究顶管施工对既有轨道和路基的变形规律,对比数值模拟结果和监控数据得出两者沉降趋势一致,施工期间最大沉降和残余形变分别为-6. 7mm和-4. 48mm,验证了该工程的安全性,对同类工程的施工具有指导意义。

When a pipe culvert is constructing underneath existing railway,it will inevitably cause the surrounding stratum to move and affect the normal operation of the railway.According to different soil behavior and buried depths of pipe culverts,three-dimensional numerical model is established.The natural gas pipe culvert project of Zhaotong branch underneath the Shanghai-Kunming railway is taken as the research object,its constructing process is taken simulation analysis by MIDAS GTS NX.Meanwhile,the intelligent digital static level gages of JMDL-62XX is used to monitor the subgrade settlement during construction.The research focuses on the deformation law of the existing rails and subgrade.Comparing between the results of simulation analysis and monitor data,it shows the tendency of them is same.And the maximum settlement and residual deformation during construction are-6.7mm and-4.48mm respectively.The paper verifies the safety of the project,and has guiding significance for the construction of similar projects.