箱型梁毕业设计.

摘要

桥梁是道路的的重要组成部分，它可以根据跨越建筑物的不同分为跨河桥和跨线桥，本设计的桥是某市的一座中型桥，全长150米，分5跨，每跨跨径30米。本设计采用的是后张法预应力混凝土简支箱型梁桥，标准跨径是20m，梁的计算跨径是19.16m，梁长19.96m，主梁等截面箱型梁。半幅桥梁宽12m，两侧采用刚性护栏宽度各0.5m，不设人行道；桥面铺装采用8cm沥青混凝土和10cm 水泥混凝土；车道数为双向4车道；汽车荷载为公路－Ⅰ级。上部构造形式采用4梁式；梁宽为3.0m，梁预制高度为1.1m。

本设计是关于桥梁上部结构的设计，具体包括以下几个部分：桥型布置，结构各部分尺寸拟定；选取计算结构简图；恒载内力计算；活载力计算；荷载组合；预应力钢束的估算及其布置；配筋计算；预应力损失计算；截面强度验算；截面应力及变形验算；行车道板的计算，支座计算以及护栏设计。

由于本人的能力有限，本设计不免有知识点错误以及考虑疏漏之处，敬请各位指导老师随时指出，本人将会在以后的学习和工作中努力加以改正和弥补！

本设计在张弘强老师的指导下顺利完成，感谢张老师的督导和帮助！

关键词：简支箱型梁；后张法预应力；

Abstract

The bridge is an important part of the way .According to the different across buildings ,it can be divided in to across river bridge and overpass bridge.The design of the bridge is a medium-sized city.The bridge which divided into 5 spans is 150 meters long,and each span is 30 metres.The design uses the post-tensioned prestressed concrete simply supported box girder bridge, the standard span is 20meters and the calculation of beam span is 19.16m, while the beam length is 19.96 meters.The main girder is consistent section box beam. The half range of the bridge is 12 meters . Both sides of the rigid barrier width is 0.5meters,and no sidewalk. The bridge deck pavement is 8cm cement concrete and 10 cm asphalt concrete.There are four lanes for two-way,and the automobile loading for highway is first level.The upper structure form is consists of 4 beams type.The beam is breadth for 3.0 meters, and the precast height is 1.1meters.

The design is aim at the upper structure about Bridges, specifically including the following several parts:1、bridge-type layout and the determination of the size of the various parts of structures;2、Select the calculation of the structure diagram;3、Dead load internal force calculation; Live Load calculation; load combination; 4、Estimation of prestressed reinforcement and its layout，reinforcement calculation; prestress loss calculation;5、Cross-section strength checking; section stress and deformation checking；6、Lane board calculation ；7、Bearing calculation and barrier design.

While my limited capacity，there are unavoidable have some knowledge mistakes and omissions without enough consideration.I hope my respectful guide teacher can point out the errors at any time , I will word hard to correct it and make up in the future study and work!

The last but not least ,I will attached my gratitude and thanks to my guidance teacher Ms Zhang .The design is successfully completed with his help.I appreciate my thanks to his supervision and help again!

Keywords：simply supported box girder bridge；post-tensioned prestressed concrete；