张龙威+赵华+邵旭东

跨变截面连续钢箱梁桥）为研究对象，以35t标定三轴车进行跑车试验，结合有限元计算，对正交异性钢桥面疲劳细节的车桥动力性能展开研究.首先，将试验结果进行滤波处理，过滤掉噪声信号；然后，采用雨流法提取各个测点的应变幅值和循环次数；最后，按不同的疲劳细节计算出相应的冲击系数，并进行分析.研究发现：徐行与常速工况下，钢桥面均出现明显的车桥耦合现象.由于各疲劳细节处的局部刚度与构造的差异，各疲劳细节测点车桥动力冲击响应各不相同.其中，面板、U肋与隔板测点的冲击系数分别为0.219，0.245和0.394，均大于我国《正交异性钢桥面系统设计与维护指南》和美国AASHTO规定的0.15.研究结果表明目前的设计规范低估了车辆对钢桥面的动力冲击响应.

关键词：正交异性钢桥面；跑车试验；车桥耦合；冲击系数

中图分类号：TU443.32 文献标识码：AVehiclebridge Interaction Analysis of Orthotropic

（Key Laboratory for Wind and Bridge Engineering of Hunan Province， Hunan Univ， Changsha， Hunan410082， China）Abstract：This paper studied the vehicle dynamic performance of orthotropic steel deck （OSD） bridge at fatigue details， based on a series of field tests on a 35 t 3axle calibrated tractor across Fochen New Bridge （a threespan continuous steel boxgirder OSD bridge） as well as finite element analysis. The results of the field tests were first filtered to remove the noise signal. The strain range and cycle times of each strain gauge were then obtained by using rain flow method. The impact factors of fatigue details were eventually calculated. The research shows that in both the crawl case and general speed case， the OSD bridge has obvious vehiclebridge coupling vibration. Due to the differences in local stiffness and geometric construction at each fatigue detail， the impact factors at each fatigue detail exhibit different values. For instance， the impact factors of steel deck， Urib， and cutout in diaphragm are 0.219， 0.245， and 0.394， respectively， which are all larger than 0.15 specified by “Orthotropic Steel Bridge Design and Maintenance Guide” and AASHTO specification. Therefore， the current vehicle design specification underestimates the vehicle dynamic response of the OSD bridges.

Key words：orthotropic steel deck； field test； vehiclebridge interaction； impact factor

针对正交异性钢桥面体系普遍存在的疲劳开裂问题，各国的研究者展开了大量的实桥与足尺模型试验，由此得出钢桥易出现疲劳的细节，如图1所示.其中：疲劳细节①和②位于钢面板与U肋焊缝处，焊缝的疲劳寿命主要受荷载加载位置、面板厚度以及焊缝熔透程度等因素的影响.面板一侧的应力幅通常大于U肋一侧，更容易出现裂缝[1-3].细节③和④位于弧形切口处，是正交异性钢桥面受力最复杂的部位，同时受到车辆荷载引起的横向弯矩、剪力产生的面内应力以及纵向弯矩产生的面外……