摘 要

近年来，桥梁美学在桥梁建设中得到日益重视。在我国的桥梁建设中涌现了大量结构新颖，造型美观的异形拱桥。结构的异化增加了施工的难度，提高了对施工技术的要求。为实现设计目标必须考虑到施工过程中许多确定与不确定的影响因素，对桥梁进行施工过程结构分析是保证施工质量的关键。

本文首先对异形拱桥的结构特点和发展趋势做了简要介绍，概述了桥梁结构分析的目的、内容、方法，并以珠海金岛大桥为工程背景，利用Midas/Civil软件对全桥各个施工阶段进行简化模拟，并结合金岛大桥钢拱肋与钢箱梁吊装过程专项施工方案和施工图对整个施工过程进行施工有限元模拟。主要研究内容和结论如下：

(1)运用Midas/Civil对桥梁各个施工工况进行简化模拟，可以得到各个施工阶段结构的应力和变形，以及吊杆的张拉力，为结构分析提供理论依据。

(2)对珠海金岛大桥空间异形拱桥的施工方案进行概括，结合施工方案，确定施工的具体内容，同时明确合理的施工顺序，包括钢箱拱支架安装、拱肋吊装拼装等，计算关键截面的应力、变形以及吊杆张拉力。

(3)根据计算的变形值，分析不同施工阶段拱肋的变形是否符合要求。

(4)计算桥梁施工过程中的吊杆张拉力，对初张拉索力与终张拉索力进行分析，调整模型张拉索力以达到最佳受力状态。

(5)通过对异形拱桥施工过程进行研究，研究结果表明：各个施工阶段结构受力合理，应力状态良好，主梁和拱肋线形与图纸线形吻合较好，变形基本在容许范围之内，吊杆索力分布比较合理。

论文所研究内容可作为今后进行结构分析的基础，熟悉异形拱桥施工过程，了解成桥状态下异形拱桥的受力情况，应力以及变形，指导今后对类似桥型进行结构分析时吊杆张拉顺序和张拉力大小计算。

关键词：异形拱桥；施工过程；结构分析

Abstract

In recent years, bridge aesthetics has received increasing attention in bridge construction. In the construction of bridges in China, a large number of special-shaped arch bridges with novel structure and beautiful appearance have emerged. The alienation of the structure increases the difficulty of construction and increases the requirements for construction technology. In order to achieve the design goals, many factors that determine and determine the construction process must be taken into account. The structural analysis of the construction process of the bridge is the key to ensure the construction quality.

In this paper, the structural characteristics and development trends of the special-shaped arch bridge are briefly introduced. The purpose, content and method of the bridge structure analysis are summarized. The construction of Zhuhai Jindao Bridge is used as the engineering background, and the Midas/Civil software is used to carry out the construction stages of the whole bridge. Simplify the simulation, and combine the special construction scheme and construction drawing of the steel arch rib and steel box girder hoisting process of Jindao Bridge to carry out finite element simulation of the whole construction process.The main research contents and conclusions are as follows:

(1) By using Midas/Civil, the simulation of various construction conditions of the bridge is simplified, the stress and deformation of the structure at each construction stage and the tensile force of the boom can be obtained, which provides a theoretical basis for structural analysis.

(2) By summarizing the construction plan of the space-shaped arch bridge of Zhuhai Jindao Bridge, and combining the construction plan, the specific content of the construction is determined, and at the same time the reasonable construction sequence is clarified, including steel box arch bracket installation, arch rib lifting assembly, etc. stress, deformation and boom tension.

(3) According to the calculated deformation value, analyze whether the requirements of the arch ribs' deformation in different construction stages to be satisfied.

(4) The tension of the boom during the construction of the bridge is calculated, the initial cable tension and the final cable force is analyzed, and the tension of the model to achieve the best stress state is adjusted.

(5) Through the research on the construction process of the special-shaped arch bridge, the research results show that the structural stress is reasonable and the stress state is good in each construction stage. The line shape of the main beam and the arch rib is in good agreement with the linear shape of the drawing, and the deformation is basically within the allowable range. The cable force distribution is reasonable.

The research content of the thesis can be used as the basis for structural analysis in the future. The construction process of the special-shaped arch bridge is familiar with, the stress, stress and deformation of the special-shaped arch bridge are understood under the bridge state, and the strut tensioning sequence is guided in the future structural analysis of similar bridge types. And the amount of tension is calculated.

Key words： profiled arch bridge; construction process; structural analysis

目录

第一章 绪论 1

1.1 异形拱桥的结构特点 1

1.2 异形拱桥的发展和现状 2

1.2.1 异型拱桥的国外现状 2

1.2.2 异型拱桥的国内现状 3

1.3 异形拱桥的发展方向 6

1.4 本文的研究意义及主要内容 7

第二章 施工过程结构分析 8

2.1 异形拱桥的一般施工方法 8

2.1.1 有支架施工 8

2.1.2 缆索吊装施工 8

2.1.3 劲性骨架施工 8

2.1.4 转体施工 9

2.2 结构分析的研究意义 9

第三章 珠海金岛大桥施工方案 11

3.1工程概况 11

3.1.2 技术标准 11

3.1.3 桥梁设计 12

3.2 珠海金岛大桥施工方案 13

3.2.1 钢箱梁节段划分 13

3.2.2 钢箱拱支架制作、安装 15

3.2.3 拱肋吊装拼装(支架法) 17

第四章 施工阶段结构仿真计算 23

4.1 施工仿真模型建立 23

4.1.1 荷载模拟 23

4.1.2 边界条件 23

4.1.3主要材料 23

4.2 有限元模型建立 24

4.3 施工阶段的划分 25

4.4 模型结构计算与分析 26

4.4.1各施工阶段应力计算 26

4.4.2各工况拱肋变形计算 28

4.4.3吊杆初终张拉力计算 32

第五章 结论与展望 35

5.1结论 35

5.2展望 35

参考文献 37

致谢 38

第一章 绪论

1.1 异形拱桥的结构特点

一般拱桥的拱轴线型有圆弧线、悬链线、抛物线三种。而异形拱桥的合理拱轴线是一种变形曲线，它通过将吊杆斜向布置，以及改变拱肋截面等方式，不但达到了结构的强度要求，而且在造型方面相比一般拱桥所采用的吊杆、立柱竖向布置更具灵动性。但是异形拱桥的施工难度和工程造价要比一般拱桥高出许多。