三主桁钢桥横向内力调整方法与参数研究  

Study of Adjustment Method and Parameters of Transverse Internal Force in Three-Main-Truss Steel Bridge

作　　者：刘世忠 张国玺[1] 张俊光[1] 邓淑飞[1] 

机构地区：[1]长安大学桥梁与隧道陕西省重点实验室,陕西西安710064 [2]太原科技大学交通工程系,山西太原030024

出　　处：《世界桥梁》2011年第2期26-30,共5页World Bridges

基　　金：教育部新世纪优秀人才支持计划资助项目(NCET-06-0855);广东省交通厅科技项目(2007-15)

摘　　要：多主桁钢桥在成桥状态下结构受力复杂,各桁受力不均衡,以一座双层桥面三桁刚性悬索加劲钢桁梁桥——东江大桥为工程背景,介绍了通过支座升降预设横向预拱度来横向调整三桁内力技术。采用大型有限元程序建立实桥三维空间有限元模型,运用仿真分析法对该技术的有效性及相关影响参数进行了相应的研究。结果表明,利用预设横向预拱度方法使中桁支座适当沉降,可以有效地实现将中桁受力分担至两边桁,成桥后中、边桁对应控制杆件不均衡系数iη控制在±5%以内;横梁抗弯刚度EI和节点刚度K均对横向三桁内力分布的均衡性有较大影响,随EI的增大,iη逐渐减小;节点刚度K对横向三桁内力调整效果影响显著,铰接模型不均衡系数iη较刚接模型高50%左右,是决定内力调整效果的关键。针对实桥横梁与主桁连接并非完全刚接的情况,建议采用位移与支反力双控的施工措施。The structural force conditions of the multi-main-truss steel bridge in completion state are complicated and the forces among each truss are not balanced.With reference to the Dongjiang Waterway Bridge,a double-deck steel truss girder suspension bridge having three main trusses and stiffened by rigid suspension members,the method for adjusting the transverse internal force in the three main trusses by raising and lowering bearings and pre-setting transverse camber is introduced.The large-scale finite element program is employed to set up a three-dimensional finite element model for the practical bridge and the computer simulation analysis is used to conduct the corresponding study of the effectiveness of the method and the related influential parameters.The results of the study demonstrate that the appropriate lowering of the bearings under the middle truss by pre-setting the transverse camber can effectively make the force from the middle truss shared by the two side trusses and make the unbalanced coefficient ηi of the corresponding control members of the middle and side trusses of the completed bridge controlled in the range of ±5%.Both the bending stiffness EI of the floor beams and the stiffness K of the panel points have considerable influence on the balance of the transverse internal force distribution in the three main trusses.With the increase of the EI,the ηi will gradually decrease.The influence of the K on the adjustment effect of the transverse internal force is significant,the ηi of the hinged model is about 50% higher than that of the rigidly connected model,which is the key to determine the adjustment effect of the internal force.For the practical bridge on which the floor beams are not completely rigidly connected with the main trusses,it is herewith proposed that the construction measure of control of both the displacement and support reaction force should be applied.

关 键 词：三桁钢桁梁桥 双层桥面 内力调整 有限元法 

分 类 号：U441[建筑科学—桥梁与隧道工程]