超静定钢桁架桥预拱度设计的温度假载优化法  

Temperature pseudo-load optimization method for pre-camber design of statically indeterminate steel truss bridges

作　　者：李毓龙 何任远[1] 刘厚军[1] LI Yuong;HE Renyuan;LIU Houjun(China Railway Major Bridge Reconnaissance and Design Institute Co.Ltd.,Wuhan 430056,China)

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

出　　处：《现代交通与冶金材料》2023年第2期2-7,共6页Modern Transportation and Metallurgical Materials

基　　金：国家重点研发计划项目(2017YFB0304805)。

摘　　要：为使超静定钢桁架桥在成桥后达到目标线形,需要确定桁架杆件在制造阶段的无应力长度。对于超静定钢桁架桥,若采用常规温度法确定杆件的无应力长度时,可能会使拼装后的结构产生较大的杆件次内力。为此,提出了温度假载杆件的选取原则,在此基础上建立了基于拼装次内力最小化的温度假载优化法,通过假载杆件的温度荷载和桥面节点位移及冗余支座反力的关系,求解一组既满足预拱度,冗余支座次内力又较小的杆件假载温度组合。以南通市深南路大桥三跨连续钢桁梁为例验证该方法的适用性,计算发现该方法可在满足设计预拱度逼近目标预拱度的基础上,控制杆件拼装次内力满足了安装要求。该方法可为超静定钢桁架桥的预拱度设计提供参考。In order to make the steel truss bridge reach the target alignment after completion,it is nec⁃essary to obtain the unstressed length of truss members in the manufacturing stage.For statically inde⁃terminate steel truss bridge,if the unstressed length of the member is determined by the conventional temperature method,the assembled structure may produce large secondary internal force in the mem⁃bers.Therefore,this paper proposes a selection principle of temperature pseudo-load members.On this basis,a temperature pseudo-load optimization method is established via the minimization of the secondary internal force in the assembly process.Through the relationship between the temperature load of the false-loaded member and the displacement of the bridge deck node and the reaction force of the redundant abutment,a group of member false-loaded temperature combinations are solved such that the pre-camber is satisfied and the secondary internal force of the redundant abutment is also small.Finally,the three-span continuous steel truss bridge of the Shennan Road Bridge in Nantong City is taken as an example to verify the applicability of the method.The calculation shows that the method can not only control secondary internal force of the member in the assembly process to meet the installa⁃tion requirements,but also make the design camber approach the target camber.The method can provide a reference for the camber design of statically indeterminate steel truss bridge.

关 键 词：桁架桥 超静定钢桁架 预拱度 温度假载优化法 拼装次内力 

分 类 号：U448.211[建筑科学—桥梁与隧道工程]