摘 要

本桥为拆建桥梁，位于汤泉农场。新桥方案为1-13m先张法预应力空心板梁桥，桥梁全宽12m。

本计算书通过计算预应力混凝土空心板梁等上部结构及其下部结构。进行上部结构计算时，结合相关规范初步就理解空心板梁桥的设计思路方法，新桥为简支梁桥，跨径为1-13m，全长26.04m，设计交角90°桥梁横断面布置：12 m=1.5m（人行道） 9m（车行道） 1.5m（人行道）。 采用先张法预应力空心板梁构造形式，设计时应满足不同设计状况下规范规定的控制条件要求，例如承载力、抗裂性、变形及应力等要求。因此，预应力混凝土桥梁设计时，一般情况下，首先根据结构在正常使用极限状态要求正截面抗裂性或裂缝宽度限制确定预应力钢筋的数量，再由构件的承载力极限状态总要求确定普通钢筋的数量，然后进行持久状况截面承载力极限状态的计算，以及计算预应力钢筋的损失，最后进行应力验算、抗裂性验算、变形计算等，确定构件满足在承载力极限状态和正常使用极限状态下的各方面的各方面要求。进行下部结构计算时，桥台选用桩接盖梁桥台，基础选用钻孔灌注桩，直径为1.2m。结合上部结构荷载，桥台桩基按偏心受压计算，根据土层计算 桩长；计算内力，设置钢筋并进行校核。

通过毕业设计，实现了对桥梁工程专业知识的梳理，锻炼了专业技能，提高了综合素质，为进一步学习和工作打下了坚实的基础。

关键词：张拉法；空心板梁；应力损失；钻孔灌注桩；设计计算

Construction Design of Zhao Wan Bridge

ABSTRACT

The bridge is a demolition bridge and is located on Tangquan Farm. The Xinqiao Project is a 1-13m pretensioned prestressed hollow slab girder bridge with a total width of 12m.

This calculation book calculates the superstructure of the prestressed concrete hollow slab beam and its substructure. When calculating the superstructure, preliminary understanding of the design method for the hollow slab girder bridge is given in conjunction with the relevant specifications. The new bridge is a simple-supported girder bridge with a span of 1-13m, a total length of 26.04m, and a design intersection angle of 90° cross-section layout: 12 m = 1.5 m (sidewalk) 9 m (roadway) 1.5 m (sidewalk). Pretensioned prestressed hollow slab girders are used. The design shall meet the requirements of the control conditions specified in the specifications under different design conditions, such as bearing capacity, crack resistance, deformation and stress. Therefore, in the design of prestressed concrete bridges, under normal circumstances, the number of prestressed steel bars shall be determined first according to the requirements of the normal use limit state of the structure in the normal section crack resistance or crack width limit, and then the general limit value of the bearing capacity of the components shall be determined. The number of steel bars, then the calculation of the ultimate state of the bearing capacity of the cross-section under permanent conditions, and the calculation of the loss of prestressed steel bars, and finally the stress checking, crack resistance checking, deformation calculation, etc., to determine the components to meet the limit state and normal use limit of the bearing capacity. All aspects of various aspects of the state requirements. For the calculation of the substructure, the abutment is made of pile-jointed girder abutments, and the foundation is made of cast-in-place bored piles with diameters of 1.2m. In combination with the superstructure loads, the piles of abutments are calculated according to eccentric pressure, and the pile length is calculated according to the soil layer; the internal forces are calculated, and the steel bars are set and checked.

Through graduation design, we have realized the professional knowledge of bridge engineering, trained professional skills, improved the overall quality, and laid a solid foundation for further study and work.

Key word: Post-tension; Hollow slabs; Stress loss; Bored piles; Design and calculation.

目 录

第I章 方案比选 1

1. 设计资料 2

1.1 任务概况 2

1.2技术标准 2

1.3设计方案 2

1.4工程地质 2

1.5主要材料 3

1.5.1混凝土 3

1.5.2钢材 4

1.6采用的标准及主要规范 4

1.7基本计算数据表 5

2.上部结构设计 5

2.1 结构设计 6

2.1.1 横截面布置 6

2.1.2 计算截面特性 8

2.2 主梁内力计算 9

2.2.1 永久荷载(恒载)作用计算 9

2.2.2 可变作用计算 10

2.3预应力钢筋设计 25

2.3.1 预应力钢筋截面积估算 25

2.3.2 预应力钢筋布置 27

2.3.3 普通钢筋数量的估算及布置 28

2.4换算截面几何特性计算 29

2.4.1 换算截面面积 29

2.4.2 换算截面重心位置 30

2.4.3 换算截面的惯性矩 30

2.4.4 截面抗弯模量 30

2.5 预应力损失计算 30

2.5.1 锚具变形、回缩引起的预应力损失 30

2.5.2 加热养护引起的温差损失 31

2.5.3 由于钢绞线应力松弛引起的预应力损失 31

2.5.4 混凝土弹性压缩引起的预应力损失 31

2.5.5 混凝土收缩、徐变引起的预应力损失 32

2.5.6跨中截面预应力损失组合 35

2.6正常使用极限状态计算 35

2.6.1 正截面抗裂性验算 35

2.6.2 斜截面抗裂性验算 36

2.7 变形验算 38

2.7.1 正常使用阶段挠度计算 38

2.7.2 预加应力引起的反拱计算及预拱度设置 39

2.8应力验算 38

2.8.1 短暂状态应力计算 38

2.8.2 持久状态应力计算 45

2.9 支座计算 46

2.9.1 选定支座的平面尺寸 47

2.9.2 确定支座厚度 47

2.9.3 验算支座的偏转 48

2.9.4验算支座抗滑稳定性 49

2.10 最小配筋率校核 45

2.11 铰缝计算 46

2.11.1 铰缝剪力计算 50

2.11.2 铰缝抗剪强度验算 53

3. 下部结构设计 55

3.1 桥梁下部结构设计资料 55

3.2 桥台盖梁计算 55

3.2.1 荷载计算 58

3.2.2 内力计算 66

3.2.3 截面配筋设计与承载力校核 68

3.3 桥台桩基计算 70

3.3.1 荷载计算 70

3.3.2 确定桩长 72

3.3.3 桩的内力计算（法） 73

结 论 79

致 谢 80

参考文献 81