摘要
为了解大跨度部分地锚式斜拉桥的抗风性能,以一座主跨1 400m的部分地锚式斜拉桥方案为背景,采用大跨度桥梁三维非线性抗风稳定性分析方法,将地锚段主梁长度、辅助墩数量、主梁宽度和高度及桥塔高跨比等影响因素对结构自振频率、颤振临界风速和跨中处主梁位移的影响进行分析。结果表明:增大地锚段主梁长度、边跨设置辅助墩有利于提高结构自振频率和颤振临界风速,减小跨中处主梁位移,但地锚段主梁长度和辅助墩数量存在最优合理值;增加主梁宽度可以有效提高结构自振频率和颤振临界风速,减小跨中处主梁位移;增加主梁高度可以有效提高结构的颤振临界风速,但对自振频率和跨中处主梁位移影响不大;增加桥塔高度可以有效提高结构自振频率和颤振临界风速,减小跨中处主梁位移。
To investigate the wind performance of the long span partially ground-anchored cable-stayed bridges,aproposed partially ground-anchored cable-stayed bridge with a main span of1400 m was cited as an example and the effect of the influential factors,such as the main girder length of the ground-anchored section,the numbers of the auxiliary piers,the main girder width and depth and the pylon height-to-span ratios,on the structural natural vibration frequencies,flutter critical wind speeds and the main girder displacement at the midspan was analyzed,using the three-dimensional nonlinear wind stability analysis method of long span bridges.The results of the analysis reveal that the increase of the main girder length of the ground-anchored section and the arrangement of the auxiliary piers in the side spans are helpful to improve the structural natural vibration frequencies and the flutter critical wind speeds and reduce the main girder displacement at the midspan.However,the optimal values of the main girder length and the numbers of the auxiliary piers remain to be determined.The increase of the main girder width can effectively improve the structural natural vibration frequencies and the flutter critical wind speeds and can reduce the main girder displacement at the midspan.The increase of the main girder depth can effectively improve the structural flutter critical wind speeds,however,the effect of the increase of the main girder depth on the structural natural vibration frequencies and the main girder displacement at the midspan is not obvious.The increase of the pylon height can effectively improve the structural natural vibration frequencies and the flutter critical wind speeds and can reduce the main girder displacement at the midspan.
出处
《桥梁建设》
EI
CSCD
北大核心
2016年第3期23-28,共6页
Bridge Construction
基金
浙江省自然科学基金资助项目(Y15E080064)~~
关键词
部分地锚式斜拉桥
抗风稳定性
影响因素
自振频率
颤振临界风速
主梁位移
partially ground-anchored cable-stayed bridge
wind stability
influential factor
natural vibration frequency
flutter critical wind speed
main girder displacement
