土木工程毕业设计（论文）-一级公路桥设计跨径35米计算书T梁.doc

摘要
预应力混凝土简支T形梁桥由于其具有外形简单,制造方便,结构受力合理,主梁高跨比小,横向借助横隔梁联结,结构整体性好,桥梁下部结构尺寸小和桥型美观等优点,目前在公路桥梁工程中应用非常广泛。
本次毕业设计为一级公路桥设计,主梁就选用了后张法预应力混凝土简支T形梁。首先进行了桥型方案的比选,确定简支梁桥方案后,就其进行了结构设计,设计的主要内容有:拟定截面尺寸;计算控制截面的设计内力及其相应的组合值;估算预应力钢筋的数量并对其进行布置;计算主梁截面的几何特征值;计算预应力损失值;正截面和斜截面的承载力复核;正常使用极限状态下构件抗裂性及变形验算;持久状态下和短暂状态下构件截面应力验算。接着进行了简单的施工方法设计,包括施工前的准备,主要分项工程的施工方法设计,冬季和雨季的施工安排以及施工过程中的环境保护措施等。
关键词:预应力;T形梁;方案比选;结构设计;施工方法
Abstract
Prestressed concrete T-shaped girder bridges are of many advantages. They have simple outlines and can be fabricated easily. The forces that act on their structures are ratio of height of girders to span of girders is small. In landscape orientation the girders are connected by intersecting girders. Therefore the whole structure is of good entirety. And there are still many other merits, such as small size of infrastructure, the beauty of this type of bridge and so on. Because of these advantages the PC T-shaped girder bridges are now widely applied in highway bridge projects.
The paper is about the design of first class highway. Posttensioning prestressed concrete T-shaped girder is chosen as the main girder of the bridge.
In the process of the design of the bridge, parison of different types of bridge is done firstly. After firmation of the type of the bridge, the design of the structure is done, including confirming the size of cross sections, calculating the design forces of restraining sections bining them according to The Criterion, estimating the amount of prestressed steels and arranging them, calculating the geometrical traits of cross sections of girders, calculating the loss of prestress, checking the carrying capacity of cross sections, putations of the anticrack capacity of the structure and deformation in the ultimate state of normal use, and the stress of cross section respectively in the state of lasting load and in the state of temporary load. After all the work, next is the design of construction method. It includes the preparation bef