摘 要

abstract 2

第一章 绪论 3

1.1 连续梁桥简述 3

1.2 大跨度连续梁桥的发展现状 3

1.3 未来桥梁工程发展趋势 4

1.4 本文研究的目的和意义 4

1.5 本文研究的内容 5

1.6 技术路线 6

第二章 项目工程概况 7

2.1 项目介绍 7

2.2 设计技术标准 7

2.3 主要材料 7

2.4设计规范 9

第三章 连续梁桥总体设计 13

3.1 总体设计 13

3.2 截面形式及截面尺寸拟定 13

3.2.1 截面形式 13

3.2.2 箱梁板厚度 13

3.2.3 主要尺寸列表 14

3.3 主梁分段与施工阶段划分 15

3.3.1 分段情况 15

3.3.2 主梁施工方法 16

3.3.3 施工阶段的划分 16

第四章 结构计算分析 19

4.1 建立有限元模型 19

4.2 恒载内力计算 19

4.2.1 施工阶段的内力计算 19

4.2.2 中跨合龙后的内力计算 22

4.3 活载内力计算 24

第五章 预应力钢束设计 34

5.1 估算预应力钢束 34

5.1.1 计算原理 34

5.1.2 预应力钢束的估计 37

5.2 钢束布置原则 38

第六章 承载能力验算 40

6.1 内力组合及验算理论 40

6.1.1 承载能力极限状态基本组合 40

6.2 抗弯承载能力极限状态验算 40

6.3 正常使用极限状态应力验算 46

第七章 结语 49

参考文献 50

致 谢 51

附 录: 设计图纸 52

摘 要

连续梁桥具有桥面跨度大、整体性好、结构刚度大、相对变形小、抗震性能好等优点。本文以富河大桥为背景，进行设计、计算与分析。

本毕业设计为（75 120 75）m公路预应力混凝土连续梁桥设计。本设计主要采用MIDAS/Civil分析软件来进行结构内力计算，同时使用AutoCAD和Excel进行辅助设计。全桥上部结构共分为84个单元，施工阶段分为33个梁单元。桥梁从中间支座开始施工，分别向两边进行悬臂灌注施工，在两边支座附近合拢，先进行边跨合拢，再进行中跨合拢。

建好计算模型后，首先对结构进行内力分析计算，然后对钢筋数量进行估计并配置钢筋，最后定义施工阶段，进行荷载组合并验算主要控制截面的承载能力。在做完所有计算后，绘制结构设计图纸，包括桥跨布置图、一般构造图和钢筋布置图等，进行外文翻译，最后编制设计计算说明书和文档整理。

设计说明书首先介绍了大跨度连续梁桥在国内外的发展概况及其现阶段的发展情况，并指出了进行研究的目的和意义；其次，对选择大跨度连续梁桥进行方案比选，以及选择大跨度连续梁桥的优点；最后，以富河大桥为工程背景，运用大型通用软件MIDAS/Civil进行全桥的有限元模拟仿真计算，并对计算结果进行分析。

通过此次毕业设计，我系统的了解到预应力混凝土连续梁桥的设计流程，并且建立富河大桥的的结构计算模型，通过模型可以对桥梁进行施工阶段以及运营阶段的各项验算。并得到有关此桥的设计计算说明书。根据整个过程，可以绘制出有关单元，钢筋以及施工过程等的图纸，用于指导实际施工。

关键词：预应力；连续梁；悬臂施工；模型验算

Abstract

Continuous beam bridge have a series of advantages,such as the large span of the bridge deck, the integrity of the good, the structure stiffness, the relatively small deformation, good seismic performance and so on. In this paper, the rich river bridge as the background, design, calculation and analysis

This paper is the design of highway prestressed concrete continuous beam (75 120 75)m. This design mainly uses the MIDAS/Civil analysis software to carry on the structure internal force calculation, simultaneously uses the AutoCAD and the Excel to carry on the auxiliary design. The upper structure of the whole bridge is divided into 84 units, and the construction stage is divided into 33 beam elements. Bridge began construction from the middle bearing, to both sides of a cantilever casting construction respectively, besides, the bridge advanced side span closure, then the middle span closure.

After the calculation model is built, the structure is analyzed and calculated, then assess the number of reinforcement and the configuration of steel bar, load combination and check the main control section of the load capacity and deformation. After finishing all the calculations, drawing the structural design drawings, including the bridge layout, general structure and layout drawings, etc., to carry out the foreign language translation, the final preparation of the design calculation and documentation.

In the first of all, the development situation and the development of the large span continuous beam bridge at home and abroad are introduced, and the purpose and significance of the research are pointed out; Secondly, the selection of large span continuous beam bridge is selected, and the advantages of large span continuous beam bridge are selected; Finally, with the river bridge as the engineering background, the finite element simulation of the whole bridge is carried out by using the large general software MIDAS/Civil, and the results are analyzed.