大跨钢桁拱轨道横梁半刚性连接节点疲劳性能试验研究  

Fatigue test on the semi-rigid connections between railway floor beam and primary truss of long span steel truss arch bridges

作　　者：卫星[1] 李俊[1] 强士中[1] 

机构地区：[1]西南交通大学,四川成都610031

出　　处：《土木工程学报》2009年第6期73-79,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(50678150);西部交通建设科技项目(200431822317)

摘　　要：主跨552m的重庆朝天门长江大桥轨道横梁采用新的半刚性结构与主桁连接。为评估半刚性连接结构在公路及轻轨荷载共同作用下的抗疲劳性能,对其进行全寿命期疲劳试验研究。通过空间有限元分析,选取受力最不利的主桁E18节点与轨道横梁的连接结构为研究对象。参考美国AASHTO及英国BS5400设计规范,基于M iner疲劳损伤累积原则,得到轨道横梁半刚性连接结构的疲劳内力幅。采用1∶4缩尺模型,完成半刚性连接结构设计寿命期及超长服役期的疲劳试验。设计寿命期疲劳试验结果表明,朝天门长江大桥轨道横梁与主桁E18节点的半刚性连接在其设计寿命期内不会发生疲劳开裂,疲劳性能满足设计要求。全寿命期疲劳试验结果表明,轨道横梁上翼缘的连接角钢是半刚性连接结构的易损部位。A new semi-rigid connection was employed between the railway floor beam and the primary truss of the Chaotianmen Yangtze Rive Bridge in Chongqing. In order to assess the fatigue performance of the semi-rigid connection under simultaneous truck and rail loads, a full life fatigue test that Joint E18 is subjected to heavy load, thus the semi-rigid selected for study. According to Miner＇ s fatigue accumulation was carried out. The 3-D finite element analysis indicates connection between the rail floor beam and joint El8 was damage rule and referring to the AASHTO Bridge Design Specifications and the BS5400 code, the fatigue load range at the semi-rigid connection of the structure was determined. Using a model with a scale of 1：4, design life fatigue test and limit life fatigue test were carried out. Design life test results revealed that no fatigue cracks appeared in semi-rigid connection during the service life of the Bridge, and the fatigue performance of the semi-rigid connection of the Chaotianmen Yangtze Rive Bridge can meet the designed need. Limit life lest results indicated that the angle iron of semi-rigid connection at the top flange of the railway floor beam could be easily broken.

关 键 词：钢桁拱 轨道横梁 半刚性连接 疲劳试验 全寿命 

分 类 号：U448.224[建筑科学—桥梁与隧道工程] U448.36[交通运输工程—道路与铁道工程]