保通条件下中承式拱桥吊杆更换受力及变形性能分析.docVIP

保通条件下吊杆更换对中承式拱桥力学性能影响分析 高燕梅1、周志祥1、许华东2 重庆交通大学，重庆，400074，2.重庆市设计院，重庆，400015） 摘要：本文针对桥下净空较小时，采用在桥下设置临时支架进行吊杆更换，仅需在新吊杆张拉锚固时中断交通，可显著减小对道路交通的不利影响。建立空间有限元模型，分析了旌湖大桥吊杆更换时对吊杆横梁和拱肋受力及变形影响，分析表明更换时对拱肋内力影响较大，吊杆横梁若发生较大的位移，都将会导致纵梁或桥面板的开裂，进而提出吊杆更换时吊杆横梁支撑点容许最大向上位移量。 关键词：中承式拱桥，临时支架，保通条件，吊杆更换，力学性能，有限元法 中图分类号：U443.38 文献标志码：A Study on Mechanical Effect of Suspender Replacement to Half-Through Arch Bridge with Temporary Traffic Closure GAO Yanmei1, ZHOU Zhixiang1, XU Huadong2 Chongqing Jiaotong University，Chongqing 400074，China; 2. Chongqing Architectural Design Institute, Chongqing,400015,China )Abstract: Jinghu bridge is a half-through arch bridge with a small under bridge clearance, to conduct suspender replacement, temporary piers are set under bridge, traffic closure is required only when the tension and anchor of suspender, thus unfavorable effect of traffic closure is significantly reduced. This paper analyzed mechanical effect of suspender replacement to transverse girder and arch rib using spatial finite element model analysis (FEM). Results show that suspender replacement has a significant effect on internal force of arch rib, provided that large displacement are cased to suspender and transverse girder, longitudinal girder or deck will crack, therefore, allowable maximum displacements of transverse girder supports when conducting suspender replacement are proposed. Keywords: half-though arch bridge, temporary piers，suspender replacement, traffic condition, structural performance, finite element analysis 1.引言 中下拱桥造型优美，能力大，近得到日趋广泛的应用。耐久性、可靠性引发的问题，实现保通条件下的吊杆更换对交通的影响德阳市为90m的中承式提篮拱桥图1），设计荷载等级为汽－20、挂－100。 图1德阳旌湖大桥 图2吊杆PE套破损及钢丝锈蚀状况 Fig.1 Deyang Jinghu Bridge Fig.2 the Breakage PE Fagging and the Corrosion Steel Wires 3.保通条件下吊杆更换施工方法 德阳旌湖大桥位于德阳市，交通量很大，中断交通将给当地人民生活带来严重社会影响。，桥下设临时提出可实现保通条件下 图3保通条件下的吊杆更换方法 Fig.3 the method of Suspender Replacement with Temporary Traffic Closure 采用上述方式更换，在用千斤顶对吊杆进行加载或卸载中断交通，可对交通的影响。更换，在用千斤顶对吊杆进行加载或卸载中断交通，可对交通的影响。 图4德阳旌湖桥空间有限元模型 F