抗风缆布置形式对悬索桥人致振动影响分析

Analysis of influence of wind-resistant arrangement on human-induced vibration of suspension bridge

为研究人行悬索桥使用过程中抗风缆拉索不同布置形式对人行悬索桥自振特性及人致振动的影响,以某人行玻璃悬索桥为实例,采用Midas Civil软件建立抗风缆拉索设置形式为平行直拉式、交叉斜拉式、非交叉斜拉式和不设置抗风缆的有限元模型,先单独计算改变抗风缆拉索布置形式悬索桥的自振特性参数,再计算人行简谐波荷载作用下抗风缆拉索布置形式对人行桥主梁竖向及横向加速度的影响,参考德国人行桥设计指南EN03对人行桥舒适度进行评价。结果表明,设置抗风缆能提高结构的自振频率,增加结构的整体刚度;在人行简谐波荷载作用下,相比其他3个模型,增设交叉斜拉式拉索的抗风缆能有效减小主梁竖向及横向最大加速度,对人行悬索桥的人致振动舒适度的改善效果最明显。

In order to study the influence of different arrangement forms of wind-resistant stay cables on the natural vibration characteristics and human-induced vibration of pedestrian suspension bridge,using a pedestrian glass suspension bridge as an example,the finite element models of parallel straight pull,cross cable-stayed,non-cross cablestayed and no wind-resistant stay cables are established by Midas Civil software,and the natural vibration characteristics parameters of suspension bridge with different arrangement forms of wind-resistant stay cables are calculated separately.Then,the influence of the arrangement of wind-resistant stay cables on the vertical and lateral acceleration of the main girder of the footbridge under the simple harmonic load is calculated,and the comfort of the footbridge is evaluated with reference to the German footbridge specification EN03.The calculation results show that the natural frequency of the structure can be greatly improved and the overall stiffness of the structure can be increased by setting the wind-resistant hoop.Under the action of pedestrian harmonic load,compared with the other three models,the wind-resistant cable with cross stay cables can effectively reduce the vertical and lateral maximum acceleration of the main girder,and improve the human-induced vibration comfort of the pedestrian suspension bridge.