摘 要

本桥位于殷巷街道，为新建桥梁。新桥方案为3-10m预应力空心板桥，桥梁全宽8.5m。两侧桥台各设一道40型型钢伸缩缝，桥头设6m搭板。下部结构采用桩接盖梁式桥台桥墩。

本桥设计荷载为公路-I级，桥面宽度为0.5m护栏 7.5m车行道 0.5m栏杆=8.5m，单幅布置。本计算书内容包括殷巷桥预应力混凝土空心板梁的计算及其下部结构中的桥墩、桥台、桩基础的计算。在计算上部结构时，参考相关书籍及规范初步熟悉先张法预应力空心板梁桥的计算方法，并参照已建桥梁的图纸初步拟定空心板构造尺寸。本桥主梁按照部分预应力A类构件进行设计，主梁跨中横向分布系数按铰接板法计算，支点横向分布系数按杠杆法计算，同时结构设计计算符合《公路钢筋混凝土及预应力混凝土桥涵设计规范》JTG 3362-2018要求。永久作用效应和可变作用效应计算后，按照《公路桥涵设计通用规范》JTG D60-2015要求进行作用效应组合，计算得出控制截面最大的设计弯矩和剪力。接着根据正截面的抗裂要求和抗弯要求，估算出预应力钢筋和普通钢筋的数量，并合理布置。然后计算主梁截面的几何特性，进行抗弯和抗剪承载能力计算和各阶段预应力损失以及相应阶段的有效预应力计算，最后进行正常使用状态的验算。对于下部结构中的盖梁计算，考虑偏载时产生最大弯矩，对称时产生最大剪力。由于下部结构超静定，内力计算时借助结构力学求解器进行计算。同时结合上部结构的荷载，对桩柱进行配筋设计以及承载力校核与裂缝、挠度、位移等验算。

关键词：先张法；空心板梁；作用效应；承载力；验算

Construction Design of Yinxiang Bridge

ABSTRACT

The bridge is located in Yinxiang Street and is a new bridge. The new bridge scheme is a 3-10m prestressed hollow slab bridge with a full width of 8.5m. A 40-type steel expansion joint is provided on each side of the abutment, and the bridge head is provided with a 6m strap. The lower structure adopts a pile-connected girder bridge abutment pier.

The design load of this bridge is highway-I grade, the bridge deck width is 0.5m guardrail 7.5m roadway 0.5m railing = 8.5m, single-arrangement. The calculation includes the calculation of the prestressed concrete hollow slab beam of Yinxiangqiao and the calculation of the pier, abutment and pile foundation in the substructure. In the calculation of the superstructure, refer to the relevant books and specifications to get familiar with the calculation method of the pretensioned prestressed hollow slab girder bridge, and preliminarily draft the hollow slab structural size with reference to the drawings of the built bridge. The main beam of the bridge is designed according to the partial prestressed A-type members. The transverse distribution coefficient of the main beam is calculated according to the hinged plate method. The lateral distribution coefficient of the fulcrum is calculated by the lever method, and the structural design calculation is in accordance with the “road reinforced concrete and prestressed concrete bridge and culvert”. Design Specification JTG 3362-2018 requirements. After the calculation of the permanent action effect and the variable action effect, the action effect combination is calculated according to the requirements of JTG D60-2015, “General Code for Design of Highway Bridges and Culverts”, and the design bending moment and shear force with the largest control section are calculated. Then, according to the crack resistance requirements and bending requirements of the normal section, the number of prestressed steel bars and ordinary steel bars is estimated and arranged reasonably. Then calculate the geometric characteristics of the main beam section, calculate the bending and shear bearing capacity and the prestress loss at each stage and the effective prestress calculation in the corresponding stage, and finally check the normal use state. For the cover beam calculation in the lower structure, the maximum bending moment is generated considering the eccentric load, and the maximum shear force is generated when symmetrical. Since the lower structure is ultra-quiet, the internal force calculation is performed by means of the structural mechanics solver. At the same time, combined with the load of the superstructure, the design of the reinforcement of the pile and the bearing capacity check and crack, deflection, displacement and other verification.

Key words: pre tensioning method; hollow slab beam; effect; bearing capacity; checking calculation

目 录

1 设计资料 1

1.1 设计概况 1

1.2 设计标准 1

1.3 技术规范 1

1.4 主要材料 1

1.5 地质描述 2

1.6 水文条件 3

1.7 方案比选 3

2 上部结构设计 4

2.1 构造尺寸 4

2.2 空心板毛截面几何特性计算 4

2.3 作用效应计算 5

2.3.1 永久作用效应计算 5

2.3.2 可变作用效应计算 6

2.3.3 作用效应组合 12

2.4 预应力钢筋设计 14

2.4.1 预应力钢筋数量估算 14

2.4.2 预应力钢筋的布置 15

2.4.3 普通钢筋数量的估算及布置 15

2.5 截面几何特性计算 17

2.6 截面承载能力极限状态计算 18

2.6.1 跨中截面正截面抗弯承载力计算 18

2.6.2 斜截面抗剪承载力计算 19

2.7 预应力损失计算 20

2.7.1 锚具变形、钢筋回缩和接缝压缩引起的应力损失（） 21

2.7.2 加热养护引起的温差损失（） 21

2.7.3 混凝土弹性压缩引起的应力损失（） 21

2.7.4 钢筋松弛引起的预应力损失（） 21

2.7.5 混凝土收缩、徐变引起的损失（） 22

2.8 抗裂性验算 23

2.8.1 正截面抗裂性验算 23

2.8.2 斜截面抗裂性验算 24

2.9 主梁变形计算 28

2.9.1 正常使用阶段的挠度计算 28

2.9.2 预加应力引起的反拱计算及预拱度设置 29

2.10 应力验算 30

2.10.1 短暂状况应力验算 30

2.10.2 持久状况应力验算 32

2.11 最小配筋率校核 34

2.12 铰缝计算 35