摘要
对大跨度钢箱连续梁桥施工过程最大悬臂状态进行非线性气动稳定性分析。提出基于风荷载非线性及结构几何非线性的气动稳定性分析理论。以某跨海大桥为工程背景,进行静风效应及风致抖振效应计算,明确钢箱梁最大悬臂状态位移响应均方根最大值,并以结构一期恒载作用下的位移为初始缺陷,静风力与抖振力作为荷载进行主梁最大悬臂状态非线性气动稳定性验算。结果表明,随着桥位处风速的增加,主梁悬臂端和跨中水平及竖向位移均呈现非线性增长趋势;结构的位移响应随着风攻角的正负变化而产生变化,风荷载的影响不容忽视。由于主梁刚度较大,在120 m·s-1风速范围内并没有出现失稳临界状态,但悬臂端水平及竖向位移变化幅度较大,为了保证人员安全及合龙顺利进行,提出3种抗风措施。
Nonlinear aerodynamic stability of the maximum cantilever state of long- span continuous steel box bridge in the construction process was analyzed. Aerodynamic stability analyses based on wind load nonlinearity and geometry nonlinearity were proposed. A cross-sea bridge was taken as the subject,and the effects of static wind force and buffeting force were calculated and the maximum RMS of displacement response in the longest cantilever state was determined. The nonlinear aerodynamic stability analysis of the maximum cantilever state was carried out taking static wind force and buffeting force as the external load and the displacement under the dead load as initial defect. The results show that with the increase of wind speed,the horizontal and vertical displacement of the cantilever end and mid-span of the steel box girder both had a nonlinear increasing trend; the displacement response changed with the positive and negative transformation of wind attack angle,so the influence of wind load should not be ignored. Due to high stiffness of the steel box girder,the buckling critical state did not appear within the wind speed of 120 m·s-1,but the horizontal andvertical displacement of the cantilever end were relatively large. Three measures for wind resistance were proposed to ensure safety of the personnel and smooth closure process.
出处
《科技导报》
CAS
CSCD
北大核心
2015年第1期75-80,共6页
Science & Technology Review
基金
交通运输部西部交通建设科技项目(2011812318970)
中央高校基本科研业务费专项资金项目(CHD2012JC001)
关键词
桥梁工程
高风速区
气动稳定性
风致抖振
bridge engineering
high wind speed region
aerodynamic stability
buffeting force
