高速铁路路桥过渡段地基加固技术研究

发布时间：2018-02-22 17:25

本文关键词： 路桥过渡段差异沉降 CFG桩复合地基数值计算动力学分析　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着高速铁路的快速发展,路桥过渡段差异沉降问题日益凸显,尤其是位于软土等特殊地基条件下的高速铁路工程,且随着列车车速和列车轴重的不断提高,对过渡段处的差异沉降要求更为严格,"桥头跳车"问题已成为影响高速列车行车安全的重要因素之一。鉴于目前的现状,本文以理论分析和数值计算为研究手段,系统地分析了软弱土地段高速铁路路桥过渡段的沉降规律并提出了相应的地基处理方法。本文首先论述了常见的软土地基处理方法,分析了各种处理方法的优缺点和适用性,比较得出CFG桩复合地基是更适合于软土地段高速铁路路桥过渡段的地基处理方法。基于有限元方法建立了高速铁路路桥过渡段二维数值模型,数值计算得出了路桥过渡段路基面沿纵向的沉降规律,并分析了过渡段材料参数变化对路基面沉降的影响。在此基础上,提出了几种基于CFG桩复合地基的过渡段地基处理方法,对比分析了各方案对过渡段差异沉降的过渡效果,对CFG桩复合地基处理高速铁路路桥过渡段软弱地基给出了优化建议。基于文中提出的一种CFG桩复合地基处理方案,建立了高速铁路路桥过渡段轨道-路基-CFG桩复合地基三维有限元动力模型,分析得出了列车激振荷载作用下过渡段处复合地基的动应力分布规律,以及桩、土竖向加速度沿路基横向及深度方向的衰减特征。本文所得结论可丰富高速铁路路桥过渡段地基加固技术,对软土地段的过渡段地基处理具有借鉴意义,为类似工程的设计提供了参考。
[Abstract]:In recent years, with the rapid development of high-speed railway, the problem of differential settlement in the transition section of road and bridge has become increasingly prominent, especially in the high-speed railway project under special foundation conditions, such as soft soil, and with the increasing of train speed and axle load. The requirement of differential settlement at the transition section is more stringent, and the problem of "bridge-head jumping" has become one of the important factors affecting the safety of high-speed trains. In view of the present situation, this paper takes theoretical analysis and numerical calculation as the research means. This paper systematically analyzes the settlement law of the highway and bridge transitional section of high speed railway in soft soil section and puts forward the corresponding foundation treatment methods. Firstly, this paper discusses the common soft soil foundation treatment methods, and analyzes the advantages and disadvantages and applicability of various treatment methods. It is concluded that CFG pile composite foundation is a more suitable foundation treatment method for highway and bridge transition section of high speed railway in soft soil area. Based on finite element method, a two dimensional numerical model of highway bridge transition section of high speed railway is established. The settlement law along the longitudinal surface of the road and bridge transition section is obtained by numerical calculation, and the influence of the material parameters of the transition section on the settlement of the subgrade surface is analyzed. On this basis, several methods for treating the foundation of the transition section based on the CFG pile composite foundation are put forward. The effect of each scheme on the differential settlement of the transition section is compared and analyzed, and the optimization suggestions for the treatment of soft foundation in the transition section of high speed railway road and bridge by CFG pile composite foundation are given. Based on a CFG pile composite foundation treatment scheme proposed in this paper, Three dimensional finite element dynamic model of the composite foundation of track subgrade CFG pile in the transition section of highway and bridge of high speed railway is established. The dynamic stress distribution law of the composite foundation in the transition section under the action of train excitation and the pile are obtained. The attenuation characteristics of soil vertical acceleration along the lateral and depth direction of the road foundation. The conclusions obtained in this paper can enrich the foundation reinforcement technology of the transition section of the highway and bridge of the high-speed railway, and can be used for reference for the foundation treatment of the transition section in the soft soil section. It provides a reference for the design of similar engineering.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U213.1;U445.55

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