摘 要

本设计采用装配式预应力混凝土空心板简支梁桥，跨径组成为3×10m，基础采用双柱式钻孔灌注桩。其上部结构由12片主梁以及桥面附属结构组成，主梁计算中以中跨结构作为计算主体，边跨均以构造图进行设计，桥面部分则包括桥面铺装和栏杆等。而盖梁、桥墩、基础等共同组成了下部结构。

在设计中，桥梁上部结构的计算着重分析了桥梁永久作用内力以及可变作用内力，采用单块空心板自重荷载集度进行永久作用内力的计算，按照公路—Ⅱ级车道荷载布置活载，并进行了梁内的钢筋的估算及布置。接着验算了跨中正截面和斜截面的承载力，估算了钢绞线的各种预应力损失，最后进行了正常使用极限状态下截面的抗裂性验算，主梁变形验算以及持久和短暂状况下的应力验算。

支座采用了板式橡胶支座，尺寸根据上部结构的内力和温差进行确定，由此进行支座偏转和稳定性验算。

在下部结构的设计中，按从上到下的顺序：先计算的是盖梁，着重计算了盖梁在使用过程中上部结构内力和盖梁自重的作用，通过荷载集度进行盖梁内力的计算以及配筋，验算盖梁的承载力；然后是桥墩所受荷载的计算及双柱反力的计算，由此进行配筋计算并进行验算；最后是钻孔灌注桩的设计，先根据经验公式确定桩长，再用m法确定桩的内力。

关键词：预应力 先张法 简支 空心板梁

Construction drawing design of Nan Sheng Bridge

ABSTRACT

This design adopts prestressed concrete hollow slab simple-supported beam bridges with a span of 3×10m. The foundation uses double-column cast-in-place bored piles. The superstructure consists of 12 main beams and ancillary structures on the deck. In the calculation of the main beam, the mid-span structure is used as the calculation body, and the side spans are all designed with structural drawings. The deck sections include bridge deck paving and railings. The cover beams, piers, and foundations together form the lower structure.

In the design, the calculation of the bridge superstructure focuses on the analysis of the permanent internal forces of the bridge and the internal forces of the variable forces. The calculation of the permanent internal forces is performed using the load density of the single hollow slab, and the live load is arranged according to the road-level II lane load. The evaluation and layout of the steel bars inside the beams were carried out. Then, the bearing capacity of the mid-section and oblique section of the midspan was checked, and various prestress losses of the strand were estimated. Finally, the crack resistance of the section under normal service limit state was checked, the main beam deformation was checked, and the stress of long-term and transient conditions were checked.

The bearing adopts a plate rubber bearing, and the size is determined according to the internal force and temperature difference of the upper structure, thereby performing the support deflection and stability check.

In the design of bottom structure, according to the order from top to bottom: the first is calculation of capping beam, emphatically capping beam was calculated in the process of using the upper structure internal force and the role of capping beam self-respect, by load set degree of capping beam internal force calculation and reinforcement, calculating the bearing capacity of the capping beam; Then the calculation of the load on the pier and the calculation of the double column reaction force are carried out. Finally, the design of bored cast-in-place pile is carried out. First, the pile length is determined according to the empirical formula, and then the internal force of pile is determined by m method.

Keywords: prestressed,pretensioning method,simply-supported,hollow board beam

目 录

目 录 - 1 -

1 设计说明 - 1 -

1.1 主要技术指标 - 1 -

1.2 材料规格 - 1 -

1.3 设计要点 - 2 -

1.4 设计依据和标准 - 2 -

2 结构尺寸 - 3 -

2.1 空心板中板断面 - 3 -

2.2 空心板边板断面 - 3 -

2.3 桥面横断面布置图 - 4 -

2.4 铰缝断面 - 5 -

2.5 空心板截面几何特性计算 - 5 -

3 作用效应计算 - 8 -

3.1 永久作用效应计算 - 8 -

3.2 可变作用效应计算 - 9 -

3.3 作用效应组合 - 15 -

4 钢筋的估算及布置 - 18 -

4.1 预应力钢筋的估算 - 18 -

4.2 预应力钢筋的布置 - 19 -

4.3 普通钢筋数量的估算及布置 - 20 -

5 换算截面几何特性计算 - 23 -

5.1 换算截面面积 - 23 -

5.2 换算截面重心位置 - 23 -

5.3 换算截面惯性矩 - 23 -

5.4 换算截面弹性抵抗矩 - 24 -

6 承载能力极限状态计算 - 25 -

6.1 跨中截面正截面抗弯承载力计算 - 25 -

6.2 斜截面抗剪承载力计算 - 25 -

7 预应力损失计算 - 29 -

7.1 锚具变形、回缩引起的预应力损失 - 29 -

7.2 预应力钢筋与台座之间的温差引起的预应力损失 - 29 -

7.3 预应力钢绞线由于钢筋松弛引起的预应力损失 - 29 -

7.4 混凝土弹性压缩引起的预应力损失 - 30 -

7.5 混凝土收缩和徐变引起的预应力损失 - 31 -

7.6 预应力损失组合计算 - 34 -

8 正常使用极限状态计算 - 36 -

8.1 正截面抗裂性计算 - 36 -

8.2 斜截面抗裂性验算 - 37 -

9 主梁变形验算 - 42 -

9.1 正常使用阶段的挠度计算 - 42 -

9.2 预加力引起的反拱度计算及预拱度的设置 - 42 -

10 持久状况应力验算 - 45 -

10.1 跨中截面混凝土正压应力的验算 - 45 -

10.2 跨中截面预应力钢绞线拉应力的验算 - 45 -

10.3 斜截面主应力验算 - 46 -

11 短暂状况应力验算 - 51 -

11.1 跨中截面 - 52 -

11.2 截面 - 53 -

11.3 支点截面 - 54 -

12 最小配筋率复核 - 56 -

13 支座计算 - 56 -

13.1 支座平面尺寸 - 57 -

13.2 支座厚度 - 57 -

13.3 支座验算 - 60 -

14 盖梁计算 - 63 -

14.1 荷载计算 - 63 -

14.2 内力计算 - 72 -

14.3 截面配筋设计与承载力校核 - 73 -

15 墩柱计算 - 79 -

15.1 作用效应计算 - 79 -

15.2 截面配筋计算及应力验算 - 81 -

16 桩基设计 - 84 -