既有铁路多股道条件下深基坑大跨度架空顶进框架桥的技术研究

发布时间：2018-07-29 06:11

【摘要】：随着“一带一路”战略驱动的持续推进,列车时速行车密度的提高,对列车线路的使用需求日益增大。鉴于此,平交改立交的方式愈加迫切。而大跨度框架桥所占比重越来越大,为满足大跨度框架桥刚度的要求则需加厚结构断面,从而增加结构自重和顶力,施工难度和工程造价大大增加,受力状况变得比较复杂,施工中影响因素更多。因此,如何减少对既有线路的行车影响,使框架桥快速、准确就位,以及解决架空、顶进过程中出现的各种问题,减少施工中对框架桥力学条件的不利影响,成为框架桥施工控制中迫切需要解决的问题。本文依托南水北调中线总干渠焦枝线平顶山西铁路暗渠工程为背景,采用一种特殊的结构和施工工法来满足本项目的要求,重点研究在既有铁路多股道条件下深基坑大跨度架空顶进的结构设计和施工工法。本文采用Midas GTS有限元软件进行数值模拟计算,首先进行模型的建立,定义各种相关因素,并对边界条件和荷载进行定义与施加。结合工程实例,通过有限元计算与实际监测,分析不同工况下结构的位移与应力,目的在于论证本文所提出的工法的合理性与可行性。本文在借鉴常规架空顶进的基础上,结合项目实际情况,化整为零,创造性地将单层结构调整为分体式双层结构;将成熟的单次架空顶进工法升级为两次架空、分层多次顶进的新型工法,保证了项目的顺利实施。本研究的内容不但具有科研意义,还能用于指导工程实践,对类似的工程起到很大的借鉴作用。
[Abstract]:With the continuous development of "Belt and Road" strategy driving and the increasing of train speed density, the demand for the use of train line is increasing day by day. In view of this, the way of level-to-turn interchange is becoming more and more urgent. However, the proportion of long-span frame bridge is more and more large. In order to meet the requirement of stiffness of long-span frame bridge, it is necessary to strengthen the section of the structure, thus increasing the weight and the top force of the structure, increasing the construction difficulty and engineering cost, and the stress condition becomes more complicated. There are more influential factors in construction. Therefore, how to reduce the impact on the existing lines, to make the frame bridge fast and accurate, and to solve the various problems in the process of overhead and jacking, and to reduce the negative impact on the mechanical conditions of the frame bridge during construction. It is an urgent problem to be solved in the construction control of frame bridge. In this paper, based on the project of the main trunk channel of the South-to-North Water transfer Project in Pingdingshan West Railway, a special structure and construction method is adopted to meet the requirements of the project. The structural design and construction method of large span overhead jacking in deep foundation pit under the condition of existing railway multi-track are studied. In this paper, the Midas GTS finite element software is used for numerical simulation. Firstly, the model is established, various relevant factors are defined, and the boundary conditions and loads are defined and applied. Combined with engineering examples, the displacement and stress of structures under different working conditions are analyzed through finite element calculation and actual monitoring. The purpose of this paper is to prove the rationality and feasibility of the engineering method proposed in this paper. On the basis of drawing lessons from the conventional overhead jacking and combining with the actual situation of the project, this paper creatively adjusts the single-layer structure to the split double-layer structure, and upgrades the mature single-stage overhead jacking method to the two-stage overhead structure. The new method of stratification and multiple jacking ensures the smooth implementation of the project. The content of this study not only has scientific research significance, but also can be used to guide engineering practice, which can be used for reference to similar projects.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.4

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