大型连续钢桁梁桥顶推施工中关键节点力学分析研究  

Mechanical Analysis of Key Joints of Super-spanned Steel Truss Girder in Incremental Launching Construction

作　　者：李兆峰[1] 牛忠荣[1] 方继 丁仕洪 李文杰 LI Zhaofeng;NIU Zhongrong;FANG Ji;DING Shihong;LI Wenjie(College of Civil Engineering,Hefei University of Technology,Hefei 230009,China;Steel Structure Construction Co.LTD of China Tiesiju Civil Engineering Group,Hefei 230022,China)

机构地区：[1]合肥工业大学土木与水利工程学院,安徽合肥230009 [2]中铁四局集团钢结构建筑有限公司,安徽合肥230022

出　　处：《铁道学报》2021年第4期158-165,共8页Journal of the China Railway Society

基　　金：国家自然科学基金(11272111)。

摘　　要：大型桥梁由于施工阶段与成桥状态差异较大,在最危险施工工况下桥梁节点部位易于造成结构损伤。以石济客运专线济南黄河公铁两用桥顶推施工新技术为工程背景,采用2个尺度分步分析该钢桁梁顶推过程中关键节点的应力状态。首先对钢桁梁桥进行整体结构力学分析,再将关键节点从整体结构模型中割离,施加合理的位移和应力边界条件,建立了有效的节点力学模型,通过有限元计算得出节点区域的应力分布;并通过该桥梁施工现场力学试验获得了节点的工作应力值,数值计算结果与试验结果较吻合。依据施工过程中最不利工况的节点应力分析结果,评估了大型钢桥梁顶推施工的可行性和安全性。Because a super-spanned bridge in construction process is a non-complete structural system,the joints of the bridge are prone to structural damage under dangerous construction conditions.Based on the new technology of incremental launching construction of Jinan Yellow River highway and railway bridge on Shijiazhuang Jinan passenger dedicated line,the strategy of two scales for the bridge structure was used to analyse the working stress distributions of the key joints of the bridge in the incremental launching construction.Firstly,the internal forces of all components of the bridge structure and the reaction forces from the supports of sliders under the joint were obtained by the finite element method with the beam elements.Secondly,some key joint parts were separated from the whole structure of the bridge.The displacements and forces on the boundary of the separated joint structures were taken from the results of the finite element analysis for the whole bridge structure.Especially,the constraint conditions of the mechanical models of the joint structures were determined after the reasonable modification by means of the test results.Thirdly,the stress distributions of the joint structures were successfully obtained by using the finite element method with the shell elements.In the other hand,the stress values of some positions of the joints in the construction were measured through the mechanical test of the bridge on the construction site.The numerical results of the stress analysis of the joints are in agreement with the test results.According to the stress results of the joint analysis subjected to maximum working loads,the feasibility and safety of the incremental launching construction for the super-spanned steel truss girder were evaluated.

关 键 词：钢桁梁桥 顶推施工 节点 应力分析 有限元法 

分 类 号：U441.5[建筑科学—桥梁与隧道工程]