抗风缆斜拉索不同设置形式对人行悬索桥抗风性能的影响

Influence of Different Arrangement Forms of Wind Resistant Cable onWind Resistant Performance of Pedestrian Suspension Bridge

人行悬索桥刚度较小,结构自振频率较低,风荷载作用下容易发生振动。为了探究抗风缆在风荷载作用下对人行悬索桥稳定性的影响,先探究单独改变抗风缆拉索的布置形式对稳定性的影响,再探究抗风缆拉索布置形式及抗风缆拉索的分张角度这2个因素同时变化时对抗风稳定性的影响。基于某景区一玻璃桥面人行悬索桥,运用有限元软件对抗风缆不同布置形式下的人行悬索桥进行建模分析。结果表明:设置抗风缆后,有效的限制了人行悬索桥侧向位移,增加了结构刚度,提高其各关键振型的频率;单一改变抗风缆拉索形式时,交叉斜拉式拉索的抗风缆对人行悬索桥的抗风性能提升最明显;同时改变抗风缆拉索布置形式及抗风缆拉索的分张角度时,将抗风缆分张角度设置为30°且抗风缆拉索为交叉斜拉式时,结构的抗风稳定性能最好。

Pedestrian suspension bridge has small stiffness and low natural vibration frequency,and is prone to vibration under wind load.In order to explore the influence of wind resistant cable on the stability of pedestrian suspension bridge under wind load,first explore the influence of changing the layout form of wind resistant cable alone on the stability,and then explore the influence of wind resistant cable layout form and wind resistant cable splitting angle when these two factors change at the same time.Based on a glass deck pedestrian suspension bridge in a scenic spot,the finite element software is used to model and analyze the pedestrian suspension bridge under different layout forms of wind cables.The results show that after setting the wind resistant cable,the lateral displacement of the pedestrian suspension bridge is effectively limited,the structural stiffness is increased,and the frequency of each key vibration mode is improved;When the form of wind resistant cable is changed only,the wind resistant cable of cross cable-stayed cable improves the wind resistant performance of pedestrian suspension bridge most obviously;At the same time,when the layout form of wind resistant cable and the splitting angle of wind resistant cable are changed,the wind resistant stability of the structure is the best when the splitting angle of wind resistant cable is set to 30°and the wind resistant cable is cross cablestayed.