抗风缆对人行悬索桥动力特性和静风稳定性的影响  

Influences of Wind Cables on Dynamic Properties and Aerostatic Stability of Pedestrian Suspension Bridges

作　　者：吴长青[1] 张志田[1] 吴肖波 

机构地区：[1]湖南大学风工程试验研究中心,湖南长沙410082 [2]中铁大桥科学研究院有限公司,湖北武汉430034 [3]桥梁结构健康与安全国家重点实验室,湖北武汉430034

出　　处：《桥梁建设》2017年第3期77-82,共6页Bridge Construction

基　　金：国家自然科学基金项目(51178182;51578233)~~

摘　　要：悬索桥可通过设置抗风缆来提高其结构的抗风稳定性。为了解抗风缆不同布置形式和水平张力对人行悬索桥自振频率和扭转发散临界风速的影响,以某新建人行悬索桥为例,采用ANSYS软件建立全桥有限元模型,分别计算抗风缆与水平面夹角为0°、45°、90°3种布置形式和水平张力为2.77,3.27,3.77,4.27 MN 4种工况下该桥的关键振型频率和静风扭转发散临界风速,分析其动力特性和静风稳定性。结果表明:设置抗风缆可以提高人行悬索桥各关键振型的频率;抗风缆的3种布置形式对加劲梁的侧弯、竖弯频率提高幅度较大,而对扭转频率的提高幅度相对较小;随着抗风缆水平张力的增加,人行悬索桥各关键振型的频率均有所增加但增幅很小;设置抗风缆可以显著增强人行悬索桥的静风稳定性能,提高其扭转发散临界风速;在一定范围内,增加抗风缆的水平张力对扭转发散临界风速的提升并不明显。The wind stability of suspension bridge structures can be improved by means of ar-rangement of the wind cables on the structures. To investigate the influences of the different ar-rangement and different horizontal tension of the cables on the natural vibration frequencies and the critical wind speeds of aerostatic torsional divergence of the pedestrian suspension bridges, a newly built pedestrian suspension bridge in China was cited as an example. The software ANSYS was used to set up the finite element model for the whole bridge of the bridge and the frequencies of the dominating vibration modes and the critical wind speeds of the torsional divergence of the bridge under the 3 kinds of the arrangement of the cables that the included angles between the cables and the horizontal plane were 0°, 45° and 90° and under the 4 cases that the horizontal tension of the cables was 2. 77, 3. 27, 3. 77 and 4. 27 MN were respectively calculated and the dynamic properties and aerostatic stability of the bridge were analyzed. The results demonstrate that the arrangement of the wind cables can improve the frequencies of the dominating vibration modes of the pedestrian suspension bridge. The improvement from the 3 kinds of the arrangement of the cables on the lat-eral and vertical bending frequencies of the stiffening girder of the bridge is great while on the tor-sional frequencies is relatively little. With the increase of the horizontal tension of the cables, the frequencies of the dominating vibration modes increase to some extent, but the increase of the fre-quencies is very little. The arrangement of the cables can significantly enhance the aerostatic stabil-ity of the bridge and improve the critical wind speeds of the torsional divergence, but in the certain range, the improvement from the increase of the horizontal tension of the cables on the critical wind speeds is not significant.

关 键 词：悬索桥 人行桥 抗风缆 动力特性 静风稳定性 水平张力 有限元法 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]