摘 要

本设计是小魏桥施工图设计，根据设计任务书的要求和桥梁设计规范的规定，本设计采用预应力混凝土空心板简支梁桥的设计方案。设计上部结构形式为（1×16）m先张法预应力混凝土空心板梁桥，桥梁标准跨径为16m,桥面宽度：0.5m栏杆 5.0m人行道 25.0m车行道 5.0m人行道 0.5m栏杆=36 m，桥面连续。下部结构采用桩柱式桥墩台配桩基础，两头设桥头搭板。

本计算书主要计算小魏桥预应力混凝土空心板梁桥上部结构及下部结构。进行上部结构设计时，标准跨径16m，并排布置35块空心板。在上部结构计算中，首先计算主梁恒载内力，按实际结构尺寸计算恒载集度，计算应力时将荷载作用在结构上直接计算。再计算主梁活载内力，纵向采用影响线加载求最不利内力。再计算主梁预应力，采用1×7股钢绞线。最后进行应力验算、抗裂性验算、变形计算等，确定构件满足承载能力极限状态和正常使用极限状态各方面要求。在下部结构计算中首先进行盖梁的内力、配筋计算。再进行框架式基础桥台设计、验算。桥台采用桩接盖梁桥台，基础选用钻孔灌注桩。

按照设计任务的要求，本设计，有一个比较详细的设计与计算过程，绘制了19张CAD图，符合设计任务书的要求。

关键词：预应力；空心板；盖梁；桩柱

Xiao Weiqiao construction drawing design

ABSTRACT

This design is the design of the Xiawei bridge construction drawing. According to the requirements of the design task book and the specification of the bridge design, this design adopts the design scheme of the prestressed concrete hollow slab simple supported beam bridge. Design superstructure form is (1×16) m pretensioned prestressed concrete hollow slab beam bridge, the standard span of the bridge is 16m, the width of bridge surface: 0.5m railing 5.0m sidewalk 25.0m road 5.0m pavement 0.5m railing =36 m, bridge deck continuous. The lower structure adopts pile column bridge pier and pile foundation, and two ends are built by bridge head.

This calculation book mainly calculates the upper structure and the substructure of Xiaowei bridge prestressed concrete hollow slab girder bridge. For the superstructure design, the standard span is 16m, and 35 hollow plates are arranged side by side. In the calculation of superstructure, the constant load internal force of the main beam is calculated first, the constant load set is calculated according to the actual structure size, and the load is calculated directly in the structure when the stress is calculated. The internal force of the main beam is calculated, and the most unfavorable internal force is calculated by loading the influence line longitudinally.Then calculate the prestress of main girder and use 1×7 strand strand. Finally, the stress checking, crack checking and deformation calculation are carried out to determine the requirements of the components to meet the ultimate load bearing capacity and the normal serviceability limit state. In the calculation of the substructure, the internal force and reinforcement calculation of the cover beam are first carried out. Then the frame type foundation abutment is designed and checked. The bridge abutment adopts the pile connecting beam abutment, and the foundation adopts the bored pile.

According to the requirements of design tasks, this design has a more detailed design and calculation process, and draws 19 CAD diagrams, which conforms to the requirements of the design task.

Key Words: prestress；hollow slab; cover beam；pile colum

目录

1设计资料 - 1 -

1.1 主要技术指标 - 1 -

1.2材料规格 - 1 -

1.3采用的技术规范 - 1 -

2构造形式及尺寸选定 - 2 -

3空心板截面几何特性计算 - 3 -

3.1中板空心板截面几何特性计算 - 3 -

3.1.1毛截面面积 - 3 -

3.1.2毛截面重心至截面上缘距离 - 3 -

3.1.3毛截面对重心轴的惯性矩 - 3 -

3.2边板 - 4 -

3.2.1毛截面面积 - 4 -

3.2.2毛截面重心至截面上缘距离 - 4 -

3.2.3毛截面对重心轴的惯性矩 - 4 -

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板间接头（二期恒载） - 5 -

4.1.3桥面系自重（三期恒载） - 5 -

4.1.4恒载内力计算 - 6 -

4.2可变作用效应计算 - 7 -

4.2.1汽车荷载横向分布系数计算 - 7 -

4.2.2汽车荷载冲击系数计算 - 18 -

4.2.3 可变作用效应计算 - 18 -

4.3作用效应组合 - 22 -

4.3.1 承载能力极限状态 - 22 -

4.3.2 正常使用极限状态 - 23 -

5预应力钢束的估算及布置 - 25 -

5.1预应力钢筋数量的估算 - 25 -

5.2预应力钢筋的布置 - 26 -

5.3普通钢筋数量的估算及布置 - 27 -

6 换算截面几何特性计算 - 30 -

6.1 换算截面面积A₀ - 30 -

6.2 换算截面重心位置 - 30 -

6.3 换算截面惯性矩 - 31 -

6.4 换算截面弹性抵抗矩 - 31 -

7 承载能力极限状态计算 - 32 -

7.1 跨中截面正截面抗弯承载力计算 - 32 -

7.2 斜截面抗剪承载力计算 - 32 -

7.2.1 截面抗剪强度上.下限复核 - 32 -

7.2.2 斜截面抗剪承载力计算 - 33 -

8 预应力损失计算 - 35 -

8.1 锚具变形、回缩引起的应力损失 - 35 -

8.2 加热养护引起的温度损失 - 35 -

8.3 混凝土弹性压缩引起的预应力损失 - 35 -

8.4 钢筋松弛引起的应力损失 - 36 -

8.5 混凝土收缩、徐变引起的预应力损失 - 36 -

8.6 预应力损失组合 - 38 -

9正常使用极限状态计算 - 40 -

9.1正截面抗裂性验算 - 40 -

9.2斜截面抗裂性验算 - 41 -

10 变形计算 - 45 -

10.1 正常使用阶段的挠度计算 - 45 -

10.2 预加力引起的反拱度计算及预拱度的设置 - 45 -

10.2.1 预加力引起的反拱度计算 - 45 -

10.2.2 预拱度的设置 - 47 -

11 持久状态应力验算 - 48 -

11.1跨中截面混凝土的法向压应力验算 - 48 -

11.2 跨中预应力钢绞线的拉应力验算 - 48 -

11.3 斜截面主应力验算 - 49 -

12短暂状态应力验算 - 51 -

12.1 跨中截面 - 51 -

12.1.1由预加力产生的混凝土法向应力 - 51 -

12.1.2由板自重产生的板截面上、下缘应力 - 52 -

12.2截面 - 52 -

12.3支点截面 - 53 -

13 最小配筋率复核 - 56 -

14 支座计算 - 57 -

14.1 选定支座的平面尺寸 - 57 -

14.2 确定支座的厚度 - 57 -

14.3 验算支座的偏转 - 58 -