论文总字数：108321字

摘 要

悬索桥，是缆索承重体系的桥型之一，结构造型美观，经济性能好，对地形和地质状况适应性强，越来越受工程界的青睐，在大跨径桥梁中首屈一指。但随着跨径增大，宽跨比不断减小，导致桥梁的横向刚度不断减小，也会影响其动力稳定性。如何提高跨越能力的同时，保证桥梁稳定性，是悬索桥重要课题之一。

空间缆索悬索桥由于主缆和吊索形成了一个三维索系，其景观效果好，抗风能力强，动力性能优，应用可能愈来愈广泛。它在主缆内力变化不大的情况下，可改善其静力和动力稳定性。

现有的线形研究多停留于平面缆索，空间缆索线形研究较少，因此急需提出一种稳定可靠的空间缆索线形计算方法。

本次毕业设计的目标就是一座空间缆索悬索桥。首先根据规范初步拟定主梁截面尺寸、桥塔尺寸与缆索尺寸，并估得加劲梁等效质量。运用刚性支撑连续梁法在Midas中建立模型并得到初步吊杆力。建立Excel线形计算表与Midas静力模型，通过迭代得到成桥线形。建立Midas成桥模型，确定各种荷载作用下主梁产生的内力并对内力进行组合，找出最不利内力组合，据此进行梁截面设计和桥塔构件尺寸与配筋设计。最后通过Midas模型电算和手算进行承载能力极限状态和正常使用极限状态验算，并绘制施工图。

关键词：空间缆索，成桥线形，结构设计，Midas模型

The Design of Suspension Bridges with Three-Dimensionally Curved Cables

Student: Zhang Zhehong Advisor: Zhang Wenming

Abstract

Suspension bridge is one of the bridge types of cable bearing system. It has beautiful structure, good economic performance, strong adaptability to terrain and geological conditions, and is more and more popular in engineering circles. However, with the increase of span, the ratio of width to span decreases, which leads to the decrease of the lateral stiffness of the bridge and also affects its dynamic stability. How to improve the spanning capacity and ensure the stability of the bridge is one of the important subjects of suspension bridge.

Suspension bridge with Three-Dimensionally Curved Cables is a three-dimensional cable system formed by main cable and suspension cable. It has good landscape effect, strong wind resistance, excellent dynamic performance and be more and more widely used. The static and dynamic stability of the main cable can be improved when the internal force of the main cable does not change much.

Most of the existing research on alignment is focused on plane cables, and less on space cables. Therefore, a stable and reliable method for calculating the alignment of space cables is urgently needed.

The goal of this graduation project is a suspension bridge with Three-Dimensionally Curved Cables. Firstly, the section size of main girder, pylon size and cable size are preliminarily drawn up according to the code, and the dead load of the bridge is estimated. The rigid support continuous beam method is used to establish the model in Midas and obtain the preliminary suspender force. Excel alignment calculation table and Midas static model are established, and bridge alignment is obtained by iteration. Midas bridge-building model is established to determine the internal forces generated by the main girder under various loads and to combine the internal forces. The most unfavorable combination of internal forces is found out. Based on this, beam section design and tower component size and reinforcement design are carried out. Finally, the limit state of bearing capacity and normal service limit state are checked by Midas model computerization and manual calculation, and the construction drawings are drawn.

KEY WORDS: Three-Dimensionally Curved Cables, bridge alignment, structural design, Midas model

目录

第一章 结构设计方案 1

1.1设计资料 1

1.1.1工程概况 1

1.1.2设计标准 1

1.1.3主要规范 2

1.1.4主要材料 2

1.1.5设计原则 3

第二章 结构初步设计 4

2.1桥梁布置及尺寸拟定 4

2.1.1吊杆布置 4

2.1.2加劲梁截面设计 4

2.1.3桥塔墩身设计 4

2.1.4缆索截面设计 5

2.2荷载计算 6

2.2.1成桥恒载计算 6

2.2.2静阵风荷载计算 6

2.2.3其他荷载计算 8

第三章 成桥线形计算 9

3.1初算吊杆力 10

3.2线形计算 11

3.3建立简易悬索桥模型 13

3.4吊杆力迭代 14

3.5本章小结 15

第四章 有限元模型建立 16

4.1本章概述 16

4.2材料与截面的定义 16

4.3建立节点与单元组 18

4.4建立变截面组 18

4.5边界条件定义 19

4.6悬索桥分析 20

4.7荷载定义 20

第五章 内力计算 22

5.1恒载内力计算 22

5.1.1桥塔 22

5.1.2加劲梁 24

5.2活载内力计算 25

5.2.1桥塔 25

5.2.2加劲梁 29

5.3温度荷载内力计算 30

5.3.1桥塔 30

5.3.2加劲梁 34

5.4风荷载内力计算 34

5.4.1顺桥向静阵风荷载 34

5.4.2横桥向静阵风荷载 42

5.5内力组合 46

5.5.1基本组合1 47

5.5.2基本组合2 51

5.5.3频遇组合1 55

5.5.4频遇组合2 58

5.5.5准永久组合1 62

5.5.6准永久组合2 66

5.5.7标准组合1 70

5.5.7标准组合2 74

5.6本章小结 78

第六章 截面配筋计算 79

6.1构件应力结果 79

6.2截面配筋计算 84

6.2.1桥塔截面配筋 84

6.2.2桥墩截面配筋 86

6.2.3下横梁截面配筋 89

6.2.4上横梁截面配筋 91

第七章 正常使用极限状态验算 92

7.1裂缝验算 92

7.2挠度验算 94

第八章 线形对比分析 95

8.1有限元法与解析法线形对比 95

第九章 总结 98

致 谢 99

参考文献 100

第一章 结构设计方案

1.1设计资料

1.1.1工程概况

本工程为某地锚式双塔三跨悬索桥，主跨500m，左边跨200m，右边跨225m。左右塔高85m，设计矢跨比1/6~1/7，桥面总宽38.5m。左侧采用隧道式锚碇，右侧在用重力式锚碇。设计基准温度为20℃。主缆采用预制平行钢丝索股(PPWS)。单根钢丝直径6mm，抗拉强度标准值1860MPa。吊杆设计间距15m，采用的钢丝直径7mm，抗拉强度标准值1860MPa。左右主索鞍设计半径均为4m。公路I级荷载。

桥梁采用半漂浮体系空间缆索悬索桥，它的缆索与吊杆形成一个三维体系，抗风性能优异，同时桥塔采用钻石形混凝土桥塔，形式美观，造价低廉。

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