长安大学桥梁工程2015届优秀本科毕业设计 - 连续刚构桥 - 图文

二 ○ 一 五 届 毕 业 设 计

***河连续刚构桥

学 院：公路学院 专 业：桥梁工程 姓 名： 学 号： 指导教师：

完成时间：2015.06.14

二〇一五年六月

毕业设计报告

摘 要

根据设计任务书要求，依据现行公路桥梁设计规范，综合考虑桥位的地质、地形条件，提出了独塔斜拉桥、上承式钢管混凝土拱桥和预应力混凝土连续钢构三个比选方案。按“安全、经济、适用、美观和有利于环保”的桥梁设计原则，分析了三个方案的优缺点。推荐预应力混凝土连续刚构作为设计方案。推荐方案以基本设计理论为基础，参考国内外成功的大跨连续钢构桥，拟定了95m?4?170m?95m的跨径，主梁采用1.8次抛物线变梁高的单箱单室箱主梁，桥墩为双薄壁空心墩，桥台为轻型桥台，基础为群桩基础，施工阶段采取挂篮悬臂现浇法。对推荐方案进行了结构细部尺寸拟定，对上部结构和下部结构进行了内力计算、配筋设计及控制截面强度、应力验算，变形验算等。经分析比较及验算结果表明该桥梁设计合理，符合设计任务的要求。

关键词：预应力混凝土连续刚构，钢管混凝土拱桥，斜拉桥，悬臂现浇，应力验算

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毕业设计报告

ABSTRACT

According to the design requirements, the existing design specification of highway bridge, considering the geology and terrain conditions of the bridge site, after preliminary selection, three bridge type schemas are presented, they are cable-stayed bridge, arch bridge and prestressed concrete continuous rigid frame bridge . Then comparing the advantages and disadvantages of three options comprehensively by the philosophy of bridge design as “Security, Economy, Application, Beauty and Environmental Protection”. The PC continuous rigid frame bridge is selected as the recommended scheme after the selections. This project is based on the basic theory of bridge design and take the domestic and international successful designs for example, finally chose a span combination of 95m?4?170m?95m.The depth of Single cell box girder varies as the second-degree parabola, the pier is a double thin-wall hollow pier, the abutment is light abutment, the foundation is grouped piles foundation,and the the hanging basket cantilever casting construction method. Through drawing up of structure’s dimension and then design the upper and lower part of the structure ,such as calculated the internal force of dead and living load, prestressed steel design, checking the strength and stress of control cross-section. Finally, check for live load deformation. Checked by the comparison and analysis show that the design method of calculation is correct, and the distribution of reinforcement is Reasonable, so this design meet the design requirements.

Key word: prestressed concrete continuous rigid frame bridge, double thin-wall

hollow pier , cantilever casting construction

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毕业设计报告

目 录

第一章 概述 ····························· ···1

1.1 地质条件··························· ···1 1.2 主要技术指标····························1 1.3 设计规范及标准···························1 第二章 方案比选·······························2

2.1 概述···························· ····2 2.2 比选原则························· ·····2 2.3 比选方案························· ·····2

2.3.1 预应力混凝土连续刚构桥 ·············· ·····2 2.3.2 上承式钢管混凝土拱桥 ··············· ·····3 2.3.3 独塔斜拉桥 ··························4 2.4 方案比较······························5 第三章 预应力混凝土连续梁桥总体布置 ···················8

3.1 桥型布置······························8 3.2 桥孔布置······························8 3.3 桥梁上部结构尺寸拟定·················· ·····8 3.4 桥梁下部结构尺寸拟定·······················10 3.5 本桥使用材料······················ ·····11 3.6 毛截面几何特性计算··················· ·····11 第四章 荷载内力计算 ······················ ·····12

4.1 模型简介····················· ········12 4.2 全桥结构单元的划分························12

4.2.1 划分单元原则 ························12 4.2.2 桥梁具体单元划分 ······················12 4.3 全桥施工节段的划分························12

4.3.1 桥梁划分施工分段原则 ····················12 4.3.2 施工分段划分 ························13 4.4 恒载、活载内力计算··············· ·········14

4.4.1 恒载内力计算· ·············· ·········14 4.4.2 悬臂浇筑阶段内力 ······················15 4.4.3 边跨合龙阶段内力 ······················16

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毕业设计报告

4.4.4 次边跨合龙阶段内力 ·····················17 4.4.4 中跨合龙阶段内力 ······················18 4.4.5 活载内力计算 ·················· ······19 4.5 其他因素引起的内力计算······················21

4.5.1 温度引起的内力计算 ·····················21 4.5.2 支座沉降引起的内力计算 ···················23 4.5.3 收缩、徐变引起的内力计算 ··················24 4.6 内力组合······························27

4.6.1 正常使用极限状态的内力组合 ·········· ······27 4.6.2 承载能力极限状态的内力组合 ·········· ······27 4.6.3 主要荷载组合 ························27

第五章 预应力钢束的估算与布置 ················ ·····31

5.1 钢束估算························ ·····31

5.1.1 按承载能力极限计算时满足正截面强度要求 ··········32 5.1.2 按正常使用极限状态的应力要求计算 ········ ·····32 5.2 预应力钢束布置····················· ·····35 5.3 预应力损失计算····················· ·····36

5.3.1 预应力与管道壁间摩擦引起的应力损失 ············36 5.3.2 锚具变形、钢筋回缩和接缝压缩引起的应力损失··· ·····37 5.3.3 混凝土的弹性压缩引起的应力损失 ········· ·····37 5.3.4 钢筋松弛引起的应力损失 ···················38 5.3.5 混凝土收缩徐变引起的应力损失 ·········· ·····38 5.3.6 有效预应力计算 ·······················40 5.4 预应力计算······················· ·····41 第六章 强度验算 ························ ·····41

6.1 正截面承载能力验算························41 6.2 斜截面承载能力验算························43 第七章 应力验算 ······························44

7.1 短暂状况预应力混凝土受弯构件应力验算········· ·····45

7.1.1 压应力验算 ···················· ·····45 7.1.2 拉应力验算 ···················· ·····45 7.2 持久状况正常使用极限状态应力验算 ·········· ·····46

7.2.1 持久状况(使用阶段)预应力混凝土受压区混凝土最大压应力验算 46 7.2.2 持久状况(使用阶段)混凝土的主压应力验算 ······ ····46

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