土木工程毕业设计摘要

前言

毕业设计是培养学生综合运用所学的基础理论、基本知识和基本技能，分析和解决实际问题的能力。它具有很强实践性和综合性，是培养学生独立工作的一种良好途径和方法。在设计过程中，我重温和巩固了以前所学的基础理论和专业技术知识，弥补了自身在这些方面的欠缺，同时更深刻地体会到了作为一名路桥工作者无论是在设计还是在施工过程中，都必须以科学严谨的态度将理论与实践切实联系起来。在设计中，我翻阅了大量的参考资料，努力使所学的知识不断地系统化，不断地融会贯通。

本设计是株洲市芦淞大桥引桥上部结构设计，要求完成必要的毕业论文及桥梁总体布置图、主梁一般构造图、主梁施工程序示意图等图纸。

拟建大桥距株洲市一水厂取水口下游约500m，西起泰山路与长江南路的交点，跨湘江，东至株洲市芦淞区，接建宁大道。其中河东岸引桥高架跨越沿江南路、建设路后与建宁大道平交，河西岸引桥高架跨越滨江南路后与长江南路平交，另外河西岸设有半互通式立交将大桥与滨江南路相互联接。

钢桥主要由于跨越能力大、最适合于工业化制造、便于运输、安装速度快，构件易于修复和更换而且钢材强度高、材质均匀、塑性及韧性良好和可焊性好等优点，现代钢桥得到了很大发展。本次钢箱-混凝土连续梁桥的设计中中用到了材料力学、现代钢桥、钢结构、结构设计原理、结构力学、桥梁工程等学科的诸多知识。同时还从图书馆借阅了大量教学参考书，力求在设计过程中尽量做到规范、合理、清楚。此次设计使我所学的基础理论和专业技术知识更加系统、巩固、延伸和拓展，对我以后从事桥梁方面的工作具有很好的指导意义。

论文共分六章进行阐述，并配有多幅插图，力求更具说服力。限于本人水平和资料不足，设计中肯定存在诸多不足，敬请老师和同学多多批评指正！

在设计过程中，得到了莫时旭老师及路桥教研室其他老师的悉心指导，谨此表示感谢！

株洲市芦淞大桥引桥上部结构初步设计

摘要

本次设计主要是关于钢箱-混凝土连续梁桥上部结构的设计。钢箱-混凝土连续梁桥是有自重轻、承载能力高、塑形和韧性好、结构受力性能好、变形小、伸缩缝少、行车平顺舒适、抗震能力强等特点，是一种具有良好应用前景的桥型。钢箱-混凝土组合梁由钢箱梁和箱室中部分充填混凝土构成，即在正弯矩较大的跨中区段钢箱的截面上部箱室、剪力较大的边支座附近以及负弯矩和剪力均大的中支座附近的钢箱中充填混凝土。

设计桥梁跨度为50m+2×76m+50m,单幅单箱单室，桥面宽28m，分为6车道。

首先，确定主梁主要构造及细部尺寸，它必须与桥梁的规定和施工保持一致，考虑到抗弯刚度及抗扭刚度的影响，设计采用箱形梁。主梁的高度呈二次抛物线变化，因为二次抛物线近似于连续梁桥弯距的变化曲线。顶板、腹板厚度沿全桥保持不变,均为0.02m。

其次，利用桥梁博士软件分析内力结构总的内力(包括恒载和活载的内力计算)。用于计算的内力组合结果也由桥梁博士软件软件计算而得。

再次先期恒载徐变次内力、先期预应力徐变次内力、局部温度变化次内力。

然后进一步进行截面强度的验算，其中包括承载能力极限状态和正常使用极限状态。在正常使用极限状态验算中包括计算截面的钢箱-混凝土法向应力验算、截面的主应力计算。

关键词：组合梁钢箱-混凝土局部屈曲强度连续梁桥

Lu song Approach Bridge of Zhu Zhou Superstructure Designing

Abstract

The graduate design is mainly about the design of superstructure of Concerete-filled steel box bridge which is composed of steel box and concrete partially filled in steel box Girder Bridge . Steel box and concrete partially filled in steel box Girder Bridge become one of main bridge types of the most full of competion ability because of subjecting to the dint function with the structure good, having the small defomation, few of control joint,going smoothly comfort,protected the amout of engineering small and having the powerfully ability of earthquake proof and so on. For time and ability limited, the design of the substructure, transverse pre-stressing and vertical pre-stressing is not considered.

The spans of the bridge are 50+2×76+70m,main beam is respective designed, each suit has one box two room and six traffic ways,the width of the bridge surface is 28m.

The first step as to dimension the structural elements and details of which it is composed, it can’t and certainly should without being fully coordinated with the planning and working phrases of the project.Considering the distorting stiffness and the bending stiffness, box birder goes as second-parabolic curve, for second-parabolic curve is generally similar to the change of continuous bridge’s bending moments along. The section at the support is strengthened by the provision of thickened webs , bottom slabs and a cross beam , the thickness of the bottom slab and the top slab is 0.02m.

The second step is to use Doctor bridge software to analyze internal gross force of the structures (including dead load and lived load), the internal force composition can be done by using the compute results. then we can distribute the tendons to the bridge.

The third steps is to calculate first dead loads and temperature, bearing displacement, and so on.

The last steps is checking the main cross section. the work includes the load-caring capacity ultimate state and the normal service ability ultimate state as well as the main section’s being out of shape.

Key words : partially filled；concrete partially filled in steel box；local buckling;continous beam bridge