独塔叠合梁斜拉桥施工阶段模拟分析
2016-07-21张倩候振华孙建鹏姜开明
张倩 候振华 孙建鹏 姜开明
摘 要:针对叠合梁斜拉桥在施工阶段中的内力控制问题,借助Midas Civil有限元软件,采用倒拆正装迭代法对某叠合梁斜拉桥施工过程进行模拟计算,并对各构件在不同施工阶段中的静力行为和内力分布特点进行分析,诠释了施工全程中桥体关键部位内力演变机理。分析结果表明:该桥采用塔梁固结体系,第一对索间距较大且索力较小,会造成钢主梁最大拉、压应力出现在塔梁固结附近;在悬臂拼装施工时,吊机荷载会引起悬臂端桥面板出现拉应力。
关键词:叠合梁;斜拉桥;有限元;静力行为
中图分类号:U448.27 文献标志码:B
Simulation Analysis of Construction Process of Compositegirder Cablestayed Bridge
ZHANG Qian1, HOU Zhenhua1, SUN Jianpeng1, JIANG Kaiming2
(1. School of Civil Engineering, Xian University of Architecture and Technology, Xian 710055, Shaanxi, China;
2. Pingyang Headquarters of Traffic Engineering Construction, Wenzhou 325400, Zhejiang, China)
Abstract: Aimed at the problem of internal force control of compositegirder cablestayed bridge during the construction process, forwardbackward iterative method was applied to conduct the simulation calculation by means of Midas Civil, a finite element analysis software. The static behaviors and the characteristics of internal force distribution of the components in different construction stages were analyzed, and the mechanism of the development of internal force at crucial spots was expounded. The results show that with the tower rigidly connected with the girders, the first pair of cables have large span and small force, and the maximum tensile stress and compressive stress might emerge where the tower and girders are rigidly connected. When erecting the cantilevers, the crane load could cause the tensile stress at the cantilever side of the deck.
Key words: composite girder; cablestayed bridge; finite element; static behavior
0 引 言
叠合梁斜拉桥是由钢主梁与混凝土桥面板通过剪力钉、湿接缝形成组合截面共同受力的一类组合结构桥梁,具有跨越能力大、梁高小、自重轻、造价合理等优点,近年来在中国桥梁建设中得到广泛应用。但叠合梁斜拉桥的施工过程比较复杂,必须进行模拟计算来确定施工过程各阶段桥梁结构的受力和变形,从而加以管控,使其成桥状态满足设计要求。
斜拉桥施工状态是通过施工阶段模拟计算确定的,其施工阶段模拟计算方法在整个施工控制系统中起决定作用。对此国内外学者进行了相关研究,其中最早的是前联邦德国的桥梁大师F.Leonhardt提出的倒拆计算方法,基本思路是以设计规定的成桥目标状态作为计算的起点,按桥梁建造的逆顺序进行倒退分析计算,以确定桥梁施工安装各个阶段的内力状态和结构的位移状态;……
