大跨度人行钢桥动力性能测试及舒适度评估

Dynamic performance test and comfort evaluation of large-span pedestrian steel girder bridges

大跨度人行钢桥在人行荷载作用下容易产生振动,需要采取措施来控制振动。以某新建大跨度专用人行钢桥为工程背景,在建立Midas Civil有限元模型进行分析后,运用专用结构测试系统,分别对该钢桥在安装TMD(调谐质量阻尼器)减振装置前后进行相同的人行荷载作用下的动力性能测试与分析。按照各国规范中验算人致振动响应的方法,对人行桥舒适度进行评估,验证TMD的减振效果是否满足人体舒适度的要求。结果表明:当桥梁基频接近人行频率时,TMD减振装置可有效增大阻尼比,减小振动加速度,改善行人舒适度。

The large-span pedestrian steel girder bridge is prone to vibration under pedestrian loads, and measures need to be taken to control the vibration. Based on a new steel footbridge, and after the set-up of the Midas Civil finite element mode, the dedicated structure testing system is carried out to test the steel bridge's dynamic twice, which is under the same pedestrian loads before and after the installation of the TMD system, then the vibration response is compared and analyzed in this paper. The comfort degree of pedestrian bridges is evaluated according to the corresponding method of vibration calculation in the standards of each country, which confirms whether the vibration reduction effect of TMD meets the requirement of human comfort. The results show that when the fundamental frequency of the bridge is close to the pedestrian frequency, the TMD damping device can effectively increase the damping ratio, reduce vibration acceleration and improve the comfort of pedestrians.