摘 要

斜拉桥作为近现代重要的桥型之一具有外形美观、承载能力较强、能过跨越较大距离等特点，可以说在大跨径的桥梁中结合梁斜拉桥的最具有竞争力的桥型。斜拉桥本身是的结构是高次超静定结构，而且由于斜拉桥最明显的特点斜拉桥的存在，斜拉桥自身的施工过程存在独有的悬臂施工法和调整斜拉索的索力步骤，除此之外其他的施工过程中的荷载和设计与施工的偏差等因素都会对斜拉桥的最终的成桥效果产生较大的影响。斜拉桥是根据设计要求先预铸好桥主梁、横梁和桥面板等构件，然后再带到现场进行拼装和连接，所以想要保证斜拉桥最后的成桥状态能满足要求，就要在施工过程中严格控制各构件受力情况和位移变化。本文通过对西固黄河大桥的施工过程的有限元分析来探讨其他结合梁斜拉桥的施工过程中的静力分析。

通过查阅国内和国外的文献，了解到了有关于斜拉桥结合梁的历史和目前的发展状况，简单介绍了国内外关于结合梁斜拉桥的目前现状。结合梁斜拉桥的特点是自身是结构较为复杂的高次超静定问题，对于施工过程中的受力情况较为难以分析，总结了施工过程的构件受力特点和规律。介绍了西固黄河大桥在施工过程的中结构受力的特点，并同时使用有限元分析法来对施工过程进行模拟并分析了如何对大跨径斜拉桥来进行施工。

本文通过介绍以西固黄河大桥的工程背景， 通过运用Midas Civil有限元分析软件，根据斜拉桥自身的结构设计原理、构件的受力特点以及斜拉桥其悬臂的拼装工艺，建立有关于西固黄河大桥施工过程的有限元模型，通过对模型的模拟验证来确定成桥的状态是否合理，并选取具有代表性的部分施工阶段在有限元模型建好后分析其施工过程中的主梁的位移和应力是否合格来进行验证模型的准确性。

本文通过Midas Civil 软件来对西固黄河大桥施工过程进行有限元建模并分析了整个施工过程中的静力情况，并选取代表性的施工阶段包括主塔施工阶段、主梁的施工和斜拉索的张拉的过程和最后成桥阶段来分析内容包括在悬臂施工过程中主塔受到的内力变化情况和位移大小，主梁的内力的变化和位移的变化，斜拉索的索力的变化情况。

关键词：斜拉桥；结合梁；有限元分析；超静定分析；Midas Civil

Abstract

Cable-stayed bridge, as one of the most important bridge types in modern times, has the characteristics of beautiful appearance, strong bearing capacity and being able to span a large distance. It can be said that the most competitive bridge type is the combination beam cable-stayed bridge among long-span bridges. The cable-stayed bridge itself is a statically indeterminate structure with high degree. Due to the cable-stayed bridge's most obvious characteristics, the cable-stayed bridge itself has its own unique cantilever construction method and steps for adjusting the cable force of the cable. In addition, other factors such as the load in the construction process and the deviation between design and construction will have a greater impact on the final completion effect of the cable-stayed bridge. Cable-stayed bridge is to pre-cast the main girder, crossbeam, deck and other components according to the design requirements, and then take them to the site for assembly and connection. Therefore, in order to ensure that the final finished state of cable-stayed bridge can meet the requirements, it is necessary to strictly control the stress and displacement changes of each component during the construction process. Based on the finite element analysis of the construction process of Xigu Yellow River Bridge, this paper discusses the static analysis of other composite beam cable-stayed bridges during the construction process.

Through consulting domestic and foreign documents, we have learned about the history and current development of cable-stayed bridge's composite beam, and briefly introduced the current situation of cable-stayed bridge with composite beam at home and abroad. Combined with the characteristics of beam cable-stayed bridge, it is a high-order statically indeterminate problem with complex structure. It is difficult to analyze the stress situation during construction. The stress characteristics and laws of components during construction are summarized. This paper introduces the structural stress characteristics of Xigu Yellow River Bridge during the construction process, and at the same time uses the finite element analysis method to simulate the construction process and analyzes how to construct the long-span cable-stayed bridge.

This paper introduces the engineering background of Xigu Yellow River Bridge, establishes a finite element model of the construction process of Xigu Yellow River Bridge by using Midas Civil finite element analysis software, according to the structural design principle of cable-stayed bridge itself, the stress characteristics of components and the assembly process of cantilever of cable-stayed bridge. Through the simulation and verification of the model, it determines whether the state of the completed bridge is reasonable or not, and selects representative parts of the construction stage to analyze whether the displacement and stress of the main girder in the construction process are qualified after the finite element model is built to verify the accuracy of the model.

This paper introduces the engineering background of Xigu Yellow River Bridge, establishes a finite element model of the construction process of Xigu Yellow River Bridge by using Midas Civil finite element analysis software, according to the structural design principle of cable-stayed bridge itself, the stress characteristics of components and the assembly process of cantilever of cable-stayed bridge. Through the simulation and verification of the model, it determines whether the state of the completed bridge is reasonable or not, and selects representative parts of the construction stage to analyze whether the displacement and stress of the main girder in the construction process are qualified after the finite element model is built to verify the accuracy of the model.

Key Words：cable stayed bridge；Combined bridge；Finite element analysis ；Statically indeterminate analysis; Midas Civil

目 录

第1章 绪论 1

1.1 研究背景 1

1.2 结合梁斜拉桥的国内外现状 1

1.2.1 建设现状 1

1.2.2 研究现状 3

1.3 本文主要进行研究的内容 4

第2章 斜拉桥的施工过程中的受力分析和结构分析理论 5

2.1 斜拉桥施工阶段受力特点 5

2.2 有限元模型的建模方法 6

2.3 斜拉桥的施工方法分析 6

2.3.1 正装法 7

2.3.2 倒拆法 7

2.4 本章小结 7

第3章 西固黄河大桥的有限元模型分析 9

3.1 桥梁背景 9

3.2 有限元模型的建立 11

3.2.1 主梁和桥面板的模拟 11

3.2.2 斜拉索的模拟 12

3.2.3 桥塔、桥墩和支座的模拟 12

3.2.4 有限元模拟 12

3.3 本章总结 16

第4章 西固黄河大桥施工过程静力分析 17

4.1 确定合理的成桥状态 17

4.2 阶段的内力分析 20

4.3 施工过程中的各构件分析 23

4.3.1 主塔 23

4.3.2 主梁 26

4.3.3 斜拉索索力 29

4.4 总结 32

第5章 结论和展望 34

5.1 结论 34