高速列车经过时跨线天桥表面风压小波分析

列车风荷载是临近高速铁路建筑物设计和确定相关建筑限界必须考虑的重要问题。跨线天桥是典型高速铁路临近建筑物,列车经过时作用在跨线天桥表面上的气动力不可忽视。基于跨线天桥表面风压实测试验,对实测风压进行小波变换,分析天桥表面风压的脉动特性和风压脉冲影响,识别风压在不同频段的分布情况。分析表明,天桥表面压力分量在低频段比较大,在高频段比较小;风压能量在低频段比较大,在高频段比较小;列车风压的低频部分起控制作用,高频部分影响比较小。小波分析对研究跨线结构表面列车风压有很大作用,其分析方法和工程应用方法值得进一步研究。

Wavelet analysis for surface wind pressure of an over-line bridge during high-speed train passage

It is necessary to predict the aerodynamic load on buildings near the track due to high-speed train passage for designing these buildings and determining their limit. Cross-line bridge is a typical building near the track, the train-induced flow and its aerodynamic effects on bridge surface can not be ignored. Based on the pressure measured experiments of cross-line bridge, wavelet transform was made of the collected pressure, analysis of the surface pressure fluctuation characteristics and identification of the pressure distribution in different frequency bands were conducted. Analysis show that surface pressure component in low frequency band is large, while in high frequency band is relatively small, wind energy in low frequency band is large and small in high frequency band. The low frequency part of wind pressure has large impact on cross-line bridge, while the impact caused by high frequency components is small. Wavelet analysis is helpful to the study of wind pressure on the cross-line bridge surface. The analysis and application methods are worth further investigation.