减小桥面系与主桁共同作用效应的技术措施方案比选  

Scheme Comparison and Selection for Techniques Used to Mitigate Interaction Between Bridge Deck and Main Truss

作　　者：张兴志[1] 朴泷 孙英杰[1] 

机构地区：[1]中铁大桥勘测设计院集团有限公司,湖北武汉430056 [2]港珠澳大桥管理局,广东珠海519000

出　　处：《世界桥梁》2016年第3期21-24,共4页World Bridges

摘　　要：针对桥面系与主桁共同作用效应较大,设置可移动纵梁构造相对复杂且增加制造、安装和后期维养的工作量等问题,以平潭海峡公铁两用大桥80m跨径简支钢桁梁为背景,对减小桥面系与主桁共同作用效应的技术措施方案进行比选。该桥公路桥面采用纵横梁的结合梁桥面系,针对该桥结构、施工特点,提出纵梁预先缩短后安装、减小桥面系与主桁共同作用跨度、减小桥面系参与主桁共同作用长度等3种技术措施方案,采用有限元软件建立双层结合简支钢桁梁模型,计算横梁纵向变形、横梁应力和纵梁应力,并进行对比。结果表明,3种方案均对减小桥面系与主桁共同作用效应有效,纵梁预先缩短后安装方案通过调整纵梁安装缩短量,可以完全抵消共同作用效应,其余2个方案不能达到完全消除共同作用效应的影响。该桥最终采用纵梁预先缩短后安装的技术措施方案。When the interaction between the bridge deck and the main truss is great, it is not proper to install movable stringers because of the increase of works in manufacturing, installation and late maintenance. In this study, the simply-supported steel truss girder with 80 m-long spans in Pingtan Straits Rail-cum-Road Bridge was cited as an example, intending to compare and select the techniques used to mitigate the interaction between bridge deck and main truss. The highway deck of the bridge adopts the composite deck system formed of stringers and floor beams. Accord- ing to the structural features and construction characteristics of the bridge, three technical schemes were proposed, including shortening the stringers before installation, reducing the scope of the bridge deck and main truss interaction and reducing the length where bridge deck participates in the main truss interaction. The finite element software was used to establish the model of the two-lay- er composite simply-supported steel truss girder, to calculate the longitudinal deformation of the floor beams, stress in floor beams and stringers, and compare the relative results. The results of the analysis indicate that all the three schemes are proved effective in mitigating the interaction between the bridge deck and the main truss. The scheme of shortening the stringers before installation is capable of counteracting all the interaction effect through adjusting the shortening amount of the stringers, but the other two schemes could not completely get rid of the interaction effect. Fi- nally, the scheme of shortening the stringers before installation is chosen.

关 键 词：公铁两用桥 钢桁梁 桥面系 纵梁 横梁 共同作用效应 变形 应力 技术措施 

分 类 号：U445.4[建筑科学—桥梁与隧道工程]