摘 要

本次设计的题目是马河大桥施工图设计，本设计采用装配式预应力混凝土简支空心板桥，中心桩号为，跨径布置为（6×20）m，主梁为预应力简支空心板。基础采用双柱式钻孔灌注桩基础。

本文主要阐述了该桥的设计和计算过程。首先对截面尺寸进行拟定，对主桥进行总体结构设计，然后对上部结构进行内力、配筋计算，再进行强度、应力及变形验算，最后进行下部结构验算。

具体包括12个部分：1. 绪论；2. 概述；3. 尺寸拟定及截面性质计算；4. 内力组合；5. 预应力钢筋的估算及布置；6. 空心板强度计算；7. 预应力损失及有效预应力计算；8. 应力验算；9. 抗裂性验算；10. 变形验算；11. 板式橡胶支座的计算；12. 桥墩及基础配筋、强度验算。

关键词：预应力混凝土；装配式空心板桥；双柱式钻孔灌注桩

Construction drawing design of Mahe Bridge

Abstract

This design's topic is the design of the ma he big bridge.The assembly adopted the design of prestressed concrete simple hollow Panchiao, the Centre for Zhuanghao K470 840.700, span arrangement for (6×20) m, the main beam for the simple prestressed hollow plate. Based on a dual column bored pile foundation.

This paper described the bridge's design and calculation process. First of all programmes to bridge than the election, the main bridge on the overall structural design, and the upper structure of the internal forces, reinforced, further strength, stress and deformation checked, the final structure to the lower part of checking.

Specifically include the following: 1. Bridge project selection; 2. Bridge layout, the structure of the size of the development; 3. Select calculation structure diagram; 4. Heng internal forces are calculated; 5. Live on internal force calculation;6. Load combination; 7. Reinforcement calculation; 8. Prestressed loss calculation; 9. Intensity of checking cross-section; 10. Stress and deformation of checking cross-section; 11. Checking bearings; 12. Checking the lower part of the structure.

Key words：Prestressed Concrete ；Assembly Type Hollow Slab bridge；Two-column bored piles

目 录

摘 要................................................................................................................................................. I

Abstract............................................................................................................................................ II

1 绪论..............................................................................................................................................7

2 概述………………………………………………………………………………………….....8

2.1 空心板的设计…………………………………………………………………………..8

2.2 基本资料………………………………………………………………………………..8

2.3 空心板设计特点………………………………………………………………………..9

2.4 空心板受力特点………………………………………………………………………..9

3 尺寸拟定及截面性质计算…………………………………………………………………...10

3.1 基本设计资料…………………………………………………………………………10

3.1.1 设计条件………………………………………………………………………..10

3.1.2 主要材料………………………………………………………………………..10

3.1.3 设计依据及参考书……………………………………………………………..11

3.2 截面尺寸的拟定………………………………………………………………………11

3.3 毛截面几何性质计算…………………………………………………………………12

3.3.1 毛截面面积……………………………………………………………………..12

3.3.2 毛截面重心位置………………………………………………………………..12

3.3.3 毛截面对重心的惯矩…………………………………………………………..13

4 内力组合……………………………………………………………………………………...14

4.1 恒载内力计算…………………………………………………………………………14

4.1.1 空心板自重……………………………………………………………………..14

4.1.2 桥面系自重……………………………………………………………………..14

4.1.3 铰缝重…………………………………………………………………………..14

4.1.4 恒载内力计算…………………………………………………………………..15

4.2 活载内力计算…………………………………………………………………………15

4.2.1 荷载横向分布系数……………………………………………………………..15

4.2.2 活载内力计算…………………………………………………………………..19

4.3 内力组合……………………………………………………………………………...23

5 预应力钢筋的估算及布置………………………………………………………………......24

5.1 控制截面钢束面积估算……………………………………………………………...24

5.2 钢束的布置…………………………………………………………………………...26

5.3 换算截面的几何特性………………………………………………………………...26

5.3.1 换算截面的面积……………………………………………………………….26

5.3.2 换算截面的重心位置………………………………………………………….27

5.3.3 换算截面的惯矩……………………………………………………………….28

6 空心板强度计算……………………………………………………………………………..29

6.1 正截面强度计算……………………………………………………………………...29

6.2 箍筋设计……………………………………………………………………………...31

6.2.1 空心板截面尺寸检查………………………………………………………….31

6.2.2 检查是否需要进行箍筋计算………………………………………………….31

6.2.3 箍筋计算……………………………………………………………………….31

6.3 斜截面抗剪强度验算………………………………………………………………...33

7 预应力损失及有效预应力计算……………………………………………………………..34

7.1 预应力损失的计算…………………………………………………………………...34

7.1.1 锚具变形钢筋回缩和接缝压缩引起的应力损失…………………………….34

7.1.2 预应力钢筋与台座之间的温差……………………………………………….34

7.1.3 钢筋松弛引起的预应力损失………………………………………………….34

7.1.4 混凝土的弹性压缩引起的应力损失………………………………………….35

7.1.5 混凝土的收缩和徐变引起的应力损失……………………………………….35

7.2 各阶段预应力损失值的组合………………………………………………………...37

8 应力验算……………………………………………………………………………………..38

8.1 短暂状况的正应力验算……………………………………………………………...38

8.2 使用阶段空心板截面应力验算……………………………………………………...39

8.2.1 跨中截面混凝土正应力验算………………………………………………….39