论文总字数：29319字

摘 要

Abstract 6

第一章 绪论 7

1.1连续刚构桥 7

1.2合龙前顶推以及顶推力优化的目的与意义 9

1.3国内外研究进展 9

1.4本文研究内容 11

第二章 尕玛羊曲黄河特大桥的建模与分析 12

2.1尕玛羊曲黄河特大桥高墩连续刚构 12

2.2 MIDAS桥梁建模分析软件 14

2.3实例MIDAS建模 14

2.4桥梁内力及线型分析 15

2.4.1内力分析结果 15

2.4.2位移和线形分析结果 17

2.4.3小结 18

第三章 顶推力大小的计算方案及顶推工艺 19

3.1最佳成桥状态 19

3.2顶推力和顶推位移的理论关系 19

3.3尕玛羊曲黄河特大桥的最优顶推力计算方案设计 21

3.3.1函数关系中的控制参数 21

3.3.2决定顶推位移量的荷载组成 21

3.3.2收缩徐变位移量的顶推考虑折减 23

3.3.3最优顶推力计算步骤 23

3.4尕玛羊曲黄河特大桥的最优顶推力的计算 24

3.5顶推施工工艺 25

3.6本章小结 26

第四章 合龙口顶推效应分析 27

4.1施加不同大小的对顶力的内力与变形比较 27

4.1.1不同顶推力组合下的墩顶位移比较 27

4.1.2不同顶推力组合下的控制截面单元内力比较 33

4.2施加理论最优对顶力后的对顶效应分析 35

4.2.1主梁线型比较 35

4.2.2墩顶水平位移比较 36

4.2.3墩顶和墩底弯矩比较 37

4.3本章小结 37

第五章 结论和展望 38

5.1研究结论 38

5.2研究展望 38

致谢 39

参考文献 40

多跨连续刚构桥合龙口对顶技术研究

摘要

随着经济不断发展，推动了基础设施建设速度；多跨预应力连续混凝土刚构桥有着简洁优美的造型并且施工方法简单，因此而被广泛应用于公路和铁路桥梁。收缩作用、徐变作用和温度荷载会使桥梁主梁向中跨跨中缩短，容易造成严重的桥墩偏位，并使桥墩应力状态改变。为改善桥墩的应力状态，提出了在跨中合龙之前，施加顶推力的手段。本文依托尕玛羊曲黄河特大桥工程，针对多跨连续刚构桥施工中顶推力大小的确定、顶推效应以及顶推施工工艺进行讨论。本文的主要内容如下：

1. 介绍了多跨连续刚构桥合龙顶推问题的提出背景，整理了连续刚构这一形式的桥梁的发展过程、连续刚构桥的优势以及存在的缺陷，引出顶推力的讨论。
2. 介绍了依托项目——尕玛羊曲黄河特大桥的概况和结构布置，通过MIDAS软件建立了全桥全施工阶段的力学分析模型，得出了按原方案施工不施加顶推力的全桥的内力和变形分析结果，展示了不同荷载作用对主桥形状的影响效果。
3. 在理论分析的基础上，结合实际施工的具体考虑，给出利用墩顶位移分析值确定多跨连续刚构桥的顶推力的方法，并按照此方法算得尕玛羊曲黄河特大桥的最优顶推力大小；合龙顺序和合龙工艺对顶推力的影响也做了讨论。
4. 将所得最优顶推力施加在原方案模型上，对比顶推施加的效果；并通过九个通过两次顶推、按不同大小顶推力组合的桥梁模型变形和内力分析数据探讨顶推效应，并验证依据墩顶位移值确定顶推力方案是可靠的。

关键字：多跨连续刚构桥；顶推力计算；墩顶位移；顶推效应

Study on the Technology of Closure Jacking Forces in Multispan Concrete Rigid-Frame Bridges

Abstract

With the continuous development of the economy, to promote the speed of infrastructure construction, multi-span prestressed continuous concrete rigid bridge has a beautiful shape and construction method is simple, so it is widely used in highway and railway bridge. Shrinkage, creep and temperature load will shorten the bridge girder towards the middle of the span, which will cause serious piers’ deviation and make the stress state of the piers change. In order to improve the stress state of the pier, the method of applying the closure jacking forces is put forward. In this article, we discusses the determination of the closure jacking force, the pushing effect and the pushing construction technology in the construction of multi-span continuous rigid frame bridge, based on the Gamayangqu Yellow River Bridge.

Firstly, the background of the problem of multi-span continuous rigid frame bridge is introduced, and the development process of continuous rigid frame is discussed. The advantages of continuous rigid frame bridge and the existing defects are discussed. Then, this article introduces the general and the structural arrangement of the project, which is based on the MIDAS software analyze, and establishes the mechanical analysis model of the whole bridge construction stage. It is concluded that the full-bridge Internal force and deformation analysis results show the effect of different load on the shape of the main bridge. Then, on the basis of the theoretical analysis and the consideration of the actual construction, the method of determining the closure jacking force of the multi-span continuous rigid frame bridge is given by using the displacement analysis value of the top of the pier. According to this method, the optimal closure jacking force of the size of the throttle and the closure process of the impact are also discussed. Finally, the optimal top thrust is applied to the model, and the effect of the top push is applied. Through the nine model, the bridge model deformation and the internal force analysis data are discussed, And verify that the closure jacking forces is reliable based on the displacement of the top of the pier.

Key words: Multi-span continuous rigid frame bridge; Calculation of closure force; Displacement of pier’s top; Jacking effect

绪论

随着我国经济的高速增长，基础设施建设的速度加快，混凝土连续刚构桥梁被广泛的投入实际工程使用。连续刚构桥的施工方式简单高效，跨越效率也非常高。随着现代预应力技术的发展，连续刚构桥的受力性能不断得到改善，施工方法也更加的便捷。连续刚构桥的跨径通常适用于100m-250m，在这个跨径范围，三跨或者多跨的连续刚构桥是桥形选择中的首要考虑。在我国，跨径超过180m的梁桥，均为连续刚构桥结构。

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