25M后张法预应力混凝土简支T型梁桥上部结构设计..doc

内 容 摘 要 本设计为后张法预应力混凝土简支T型梁桥上部结构设计。跨径布置为25m，计算跨径24.12m, 主梁全长24.92m, 桥面宽度为净9m（行车道）+2×0.75m（防撞栏）。设计荷载：公路—I级；环境标准：I类环境；设计安全等级：二级。施工方法采用后张法，用金属波纹管和夹片锚具，预应力钢束用曲线形，用高强度低松弛预应力钢绞线。依据桥梁规范计算荷载验算应力然后确定桥梁的截面及其配筋情况，按照全预应力构件设计。 本文主要阐述了该桥的设计、计算及验算过程。首先进行了主体设计及计算。包括主梁作用效应计算；预应力钢束的估算及其布置；钢束预应力损失计算。然后进行主梁截面承载力与应力计算。主要包括承载能力极限状态计算；持久状况正常使用极限状态抗裂性验算；持久状况构件应力计算；短暂状况构件的应力验算及主梁变形验算。其次进行横隔梁和行车道板的设计。最后进行了主梁端部的局部承压验算。 关 键 词 预应力；后张法；T型梁；内力计算；强度验算 25m prestressed concrete T-beam bridge design Author: Xu Zhiwei Instructor: Jia Yan Abstract This design is the method of post-tensioning prestressed concrete simply-supported T-beam bridge upper structure design. Standard lengths：25m; calculated span :24.12m；main length :24.92m； width : 9m (carriageway) + 2 * 0.75 m (bull). Design load: highway - I, Environmental standard of environment: I;Design safety level: 2. Using the method of post-tensioning construction with metal corrugated pipe and slice the anchorage, prestressing tendons with high strength, with measures of low relaxation prestressed strands. According to the standard load and stress calculation of bridge checking design bridges section and reinforcement, according to the prestressed component design. This article mainly discusses the design and calculation of bridge and checking process. First, the main design and calculation. Including the main effect; Estimation of prestressing tendons and its layout, Steel beam prestress loss calculation. Then on deck with stress calculation capacity. Mainly includes the bearing capacity calculation limit state, Lasting condition normal use limit state cracking-resistance, checking, Lasting condition; structural stress computation Briefly state of stress calculation and structural deformation calculation girder. Next to the traffic plate and centromeres beam design. Finally the girder ends of local pressure calculation. Key words Prestressed；post-tensioning；T-beam；Internal force calculation；Strength calculation