大跨度钢—混组合体系拱桥主拱圈构造与施工方法研究

发布时间：2018-03-19 06:39

本文选题：大跨度拱桥　切入点：钢-混组合拱桥　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：本文针对特大跨拱桥,提出主拱圈拱脚区段采用钢筋混凝土箱、跨中区段采用钢箱的钢-混组合拱桥方案,以达到增大拱桥跨径、合理运用材料、减轻拱圈自重的目的。围绕钢-混组合拱桥的施工问题,提出混凝土拱圈采用悬臂浇筑法施工,钢箱采用缆索吊装法施工的组合施工方案,利用有限元程序开展施工阶段力学行为分析。本文主要工作与成果如下： ①以净跨径420m的重庆万州长江大桥为原型,开展钢-混组合拱桥试设计,主拱圈拱脚100m区段设计为单箱三室钢筋混凝土截面,跨中220m区段为单箱三室钢箱截面。对拱轴系数、矢跨比、拱上建筑、钢-混接头等构造进行初步研究,将拱厚系数、钢混分段点位置作为参数,建立ANSYS有限元空间模型,对参数变化引起的拱圈内力、拱轴系数、稳定系数变化进行研究,得出适合钢-混组合拱桥的设计参数范围。 ②根据现行公路桥涵设计规范和钢结构设计规范,用Midas/Civil和ANSYS两个有限元软件建立计算模型,进行主拱圈截面承载力验算和稳定性分析,验证试设计的可行性。 ③为减小混凝土拱圈悬臂浇筑节段的重量,加快浇筑速度,提出将拱圈分为两个边箱和一个中箱顶底板,两个混凝土边箱采用悬臂浇筑法施工,两个钢拱箱边箱采用缆索吊装法安装,实现两边箱单箱合龙,合龙后先安装焊接钢拱箱顶底板,再立模浇筑混凝土中箱顶底板,最终松开扣索,形成主拱圈结构。 ④针对钢箱区段缆索吊装施工,提出钢箱整体提升、分节段吊装两种方案,并采用ANSYS有限元软件对主拱圈施工过程进行模拟计算,对两种施工过程中截面应力、扣索索力、拱圈变形等进行对比分析,得出混凝土区段悬臂浇筑、钢区段整体提升、钢区段分节段吊装情况下的混凝土拱圈力学行为规律。
[Abstract]:In this paper, the reinforced concrete box is used in the arch foot section of the main arch ring and the steel-concrete composite arch bridge with steel box in the middle span section is put forward, so as to increase the span of the arch bridge and make reasonable use of materials. The purpose of reducing the dead weight of arch ring is to put forward the combined construction scheme of concrete arch ring by cantilever pouring method and steel box by cable hoisting method around the construction problem of steel-concrete composite arch bridge. The finite element program is used to analyze the mechanical behavior in the construction stage. The main work and results of this paper are as follows:. 1. Taking Wanzhou Yangtze River Bridge with a net span of 420 m as prototype, the trial design of steel-concrete composite arch bridge is carried out. The section of 100m arch foot of main arch ring is designed as single box and three-compartment reinforced concrete section, and the section of middle 220m span is single box three-chamber steel box section. The structure of rise-span ratio, arch building and steel-mixing joint are studied preliminarily. The ANSYS finite element space model is established by taking the arch thickness coefficient and the position of steel concrete segment as parameters, and the internal force of arch ring and the coefficient of arch axis caused by the change of parameters are studied. The range of design parameters suitable for steel-concrete composite arch bridge is obtained by studying the variation of stability coefficient. 2 according to the current design code of highway bridge and culvert and the design code of steel structure, the calculation model is established by Midas/Civil and ANSYS, and the bearing capacity of the main arch ring section is checked and the stability analysis is carried out to verify the feasibility of the test design. In order to reduce the weight of the cantilever section of concrete arch ring and speed up the pouring speed, the arch ring is divided into two side boxes and one middle box top and bottom slab, and the two concrete edge boxes are constructed by cantilever pouring method. Two steel arch box side boxes are installed by cable hoisting method to realize the closure of both sides of the single box. After closing the box, the welding steel arch box top and bottom plate is installed first, then the vertical die pouring concrete middle box top and bottom slab, finally loosening the buckle cable, forming the main arch ring structure. 4 in view of cable hoisting construction in steel box section, two schemes of steel box integral lifting and segmental lifting are put forward, and the construction process of main arch ring is simulated and calculated by ANSYS finite element software. The cross-section stress and cable buckling force are calculated during the construction process. By comparing and analyzing the deformation of arch ring, the mechanical behavior of concrete arch ring is obtained under the condition of cantilever pouring in concrete section, integral lifting of steel section and hoisting of steel section.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.4

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