摘要
本工程位于冲积平原地区，地质条件良好，适于工程建设。该桥设计荷载为公路-Ⅱ级，拟建桥长50m，桥宽11m，不设人行道。初步设计阶段综合考虑技术先进、安全可靠、适用耐久、经济合理等方面的因素后，确定最佳方案。上部结构采用后张法预应力混凝土空心板，下部采用双柱式桥墩和钻孔灌注桩。技术设计阶段根据工程要求及地质资料，按照土木工程行业的技术规范进行计算及校核。设计图纸采用AutoCAD至图软件绘制。
关键词 桥梁 钢筋混凝土 空心板 后张法 极限状态
Title 16 m prestressed concrete hollow design Pangyo
Abstract
The project is located in the alluvial plain areas, The geological condition is good and suitable for engineering and construction. Design load of this bridge is for highway grade Ⅱ,and the proposed length is 50m, width 8.5 m, with no sidewalks. The preliminary design stage considered technologically advanced, safe, reliable, and applicable durability and reasonable economic and other factors, determine the best option. The first-tensioned reinforced concrete plate is used for the superstructure, and double-column piers and bored piles for the substructure. In the technical design stage, we have to follow the requirement of engineering and geological data, According to the civil engineering industry technical standards for calculation and verification. Design drawings using AutoCAD software mapping.
Keywords Bridge Reinforced Concrete Pretensioning method
目 录
1设计资料2
1.1跨径2
1.2桥面净空2
1.3设计荷载：2
1.4材料2
1.5结构设计3
1.6 设计参数3
2造型式及尺寸选定4
3空心板毛截面几何特性计算5
4作用效应计算5
4.1永久作用效应计算5
4.1.1空心板自重（一期恒载）5
4.1.2桥面系自重g2（二期恒载）5
4.1.3恒载内力计算5
4.2基本可变荷载（活载）产生的内力6
4.2.1汽车荷载横向分布系数计算6
4.3作用效应组合14
5预应力钢筋的设计16
5.1预应力钢筋截面积的估算16
5.2预应力钢筋的布置18
6换算截面几何特性计算19
6.1换算截面面积19
6.2换算截面重心位置19
7承载能力极限状态计算21
7.1跨中截面正截面抗弯承载力计算21
7.2斜截面抗剪承载力计算22
8预应力损失计算26
8.1摩擦损失σ26
8.2锚具变形、回缩引起的预应力损失σ26
8.3混凝土弹性压缩引起的预应力损失26
8.4预应力钢绞线由于应力松弛引起的预应力损失σ27
8.5混凝土收缩、徐变引起的预应力损失27
8.6预应力损失组合设计30
9正常使用极限状态计算31
9.1正截面抗裂性验算31
9.2斜截面抗裂性验算34
10变形计算40
10.1正常使用阶段的挠度计算40
10.2预加应力引起的反拱计算及预拱度设置40
11短暂状况应力验算42
11.1跨中截面42
11.2 1/4截面44
10.3支点截面45
12持久状况应力验算47
12.1跨中截面混凝土正压应力的验算47
12.2跨中截面预应力钢绞线拉应力的验算47
12.3斜截面主应力验算48
13 最小配筋率复核52
结论与展望53
致 谢54
设计依据及参考书55
附录 图纸56
