基于随机有限元的邻近铁路地铁站基坑施工变形分析

Deformation Analysis of Foundation Pit for Subway Station Adjacent to Railway Based on Stochastic Finite Element Method

临近铁路轨道的地铁明挖车站施工往往会对铁路的路基造成影响,干扰铁路的正常运营。由于岩土材料的空间变异性,地层扰动造成的地表变形也应视为随机量。相比传统有限元,随机有限元更适合对这类问题进行分析。以南昌市轨道交通3号线上沙沟站基坑施工为背景,首先对工程涉及的地层变形参数进行了统计分析,并通过有限元反演分析获得了弹性模量参数的分布概率模型。将概率模型应用至Monte-Carlo随机有限元,分析了基坑施工对邻近铁路轨道的变形影响,得到了铁路路基沉降的分布模型以及失效概率,为今后类似工程的变形预测以及相互作用分析提供参考。

The open-cut station construction near the railway track often affects the railway subgrade and interferes with the normal operation of the railway.Due to the spatial variability of geotechnical materials,the ground deformation due to formation disturbance should be regarded as random variables.Compared with the traditional finite element method,the stochastic finite element method is more suitable for analyze of such problems.In this paper,based on the construction of the foundation pit of Nanchang railway line 3,the formation deformation parameters involved in the project are analyzed,and the distribution probability model of the elastic modulus parameters is obtained by the finite element inversion analysis.The probability model is applied to the Monte-Carlo random finite element,and the influence of the construction process of the foundation pit on the adjacent railway track is analyzed,and the distribution model and the failure probability of the railway subgrade settlement are obtained.The research results in this paper can be used as reference for deformation prediction and interaction analysis of similar projects in the future.