摘要随着时代的进步，经济的发展，交通的重要性也日益凸显。而桥梁作为道路的咽喉，其重要性不言而喻。预应力空心板桥在我国的桥梁建筑上占有重要地位，在中小跨径的桥梁中，无论是公路桥梁还是城市桥梁，很多都采用了预应力混凝土空心板桥。这种桥具有整体性好，适应性强，经济耐久，施工方便等特点。52535

本设计采用装配式预应力简支梁结构，跨径组成为2×20m，上部结构为主梁，行车道板，桥面铺装和支座等。下部结构为盖梁，桥墩，灌注桩等。设计中，上部结构的计算主要分析了恒载、活载、承载能力验算和主梁配筋，下部结构计算分析了桥墩和桩基础的承载能力。

在设计中，按照相关规范，通过各项目的计算，完整构造出一座装配式预应力混凝土简支梁桥。

毕业论文关键词：预应力，简支梁，承载力验算，钻孔灌注桩

Abstract With the progress of time, economic development, the importance of transportation are also increasingly prominent. And as  the throat of a road the bridge _its importance goes without saying. Pre-stressed Hollow Slab Bridges bridge occupies an important position in the construction in our country, during small and medium span bridges, highway bridges either or urban bridges, lot of them have adopted the pre-stressed concrete Hollow Slab Bridges. This bridge has good integrity, adaptability, economical durable and easy construction.

This design uses the assembly type pre-stressed simply supported beam structure, consisting of span is 2 × 20m, the upper structure is made up of the main beam, carriageways boards, pavement and support, etc. The substructure is made up of capping beams, piers, filling pile,etc. In the  design, the upper structure calculations mainly analyzes the constant load, the live load, load capacity checking and main beam reinforcement, The substructure calculation analysis the bearing capacity of piers and pile foundation.

In the design, according to relevant norms, through various calculation it is completely construct a assembly type pre-stressed concrete beam bridge.

Keywords: pre-stressed, Chary, Bearing Capacity, bored pile

目  录

第一章 绪论1

第二章 方案比选 2

第三章 预应力简支桥结构计算4

3.1 设计资料 4

3.1.1 设计内容  4

3.1.2 材料选用  4

3.2 构造形式及尺寸选定4

3.3 空心板毛截面几何特性计算5

3.3.1 毛截面面积 5

3.3.2 毛截面重心位置 5

3.3.3 空心板毛截面对其重心轴的惯矩 6

3.4 空心板毛截面几何特性汇总6

3.5 作用效应计算7

3.5.1 永久作用效应计算 7

3.5.2 可变作用效应计算 8

3.5.3 作用效应组合14

3.6 预应力钢筋数量估算及布置 16

3.6.1 预应力钢筋数量的估算16

3.6.2 预应力钢筋的布置19

3.6.3 普通钢筋数量估算及布置19

3.7 换算截面几何特性计算 21

3.7.1 换算截面面积21

3.7.2 换算截面重心位置22

3.7.3 换算截面惯性矩22

3.7.4 换算截面的弹性抵抗矩22

3.8 承载能力极限状态计算 23

3.8.1 跨中截面正截面抗弯承载能力计算  23

3.8.2 斜截面抗弯承载能力计算  23

3.9 预应力损失 28

3.9.1 锚具变形、回缩引起的应力损失  28

3.9.2 钢筋与台座间的温差引起的应力损失  28

3.9.3 预应力钢绞线由于松弛引起的预应力损失  28

3.9.4 混凝土弹性压缩引起的预应力损失  28

3.9.5 混凝土收缩徐变引起的预应力损失  29

3.9.6 预应力损失组合  32