预应力混凝土简支箱梁桥设计.doc

郑州航空工业管理学院
毕业设计
届专业班级
题目预应力混凝土简支梁桥设计
姓名****** 学号*********
指导教师******* 职称******
2013 年 5 月 20 日
摘要
简支梁桥是静定结构,各跨单独受力,结构受力比较单纯,不受支座变形等影响,适用于各种地质情况,结构比较简单,容易做成标准化,装配式构件,制造、安装均比较方便,是一种采用最广泛的的梁式桥。而预应力混凝土的设计是为了避免钢筋混凝土结构的裂缝过早出现,充分利用高强度钢筋及高强度混凝土,设法在混凝土结构或构件承受使用荷载前,通过施加外力,使得构件产生的拉应力减小,从而延长桥梁的使用寿命。
设计桥梁跨度为30m+30m+36m+30m+30m ,,一级公路标准,双向4车道,主梁采用预应力混凝土,后张法施工。设计过程如下:
首先,进行桥型方案分析比选,拟定主梁形式。在拟定好主梁形式后进行主梁主要构造及细部尺寸的设计,本设计采用箱形梁方案。
其次,按照规范进行主梁的作用效应计算、预应力钢束的估算及其布置并计算主梁截面几何特性。
再次,进行钢束预应力损失计算、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、主梁变形验算。
最后,进行施工方案的编制,主要包括上部结构施工,下部结构基础和墩身的施工工艺等。
关键词
箱形梁;预应力混凝土简支梁桥;后张法;施工方案
Title Prestressed concrete box girder bridge design
The name ********** Number of *********
Instructor ******* Titles *******
Abstract
Simply supported beam bridge is a statically determinate structure, each single force, force structure is relatively simple, is not affected by the deformation of the support, suitable for various geological conditions, simple structure, easy to make standardization, assembly member, manufacturing, installation is convenient, is a kind of girder bridges with the most extensive. The design of prestressed concrete is in order to avoid premature of reinforced concrete structure crack appears, make full use of high strength steel and high strength concrete, managed to concrete structures or members under service load, by applying external force, stress reduce the tension ponent, thereby prolonging service life of bridge. Prestressed concrete beam bridge generally applies to the following 50m highway bridge.
Design of the bridge span is30m+30m+36m+30m+30m, the total width of , a highway, two-way 4 lane, the main beam with prestressed concrete, post-tensioned design process is as follows:
First of all, parison and selection of bridge scheme, make girder type. Design the main structure and the size of the details in the draft girder girder type, this design uses the box beam.
Secondly, according to the standard of e