矩形高层建筑结构扭转风振反应的分析计算

Evaluation of Torsion Vibrations in Rectangular High Rise Buildings

本文应用结构随机振动理论,根据扭转运动方程提出了一个矩形高层建筑扭转风振反应的计算方法供参考。计算时同时考虑了顺风向脉动风压与横风向脉动风压的联合作用。计算结果表明,在设计风速时,结构角点处的切向加速度值小于横风向加速度值与顺风向加速度值。建筑物各表面上脉动风压之间的互相关对结构风振扭转的影响可以忽略不计。用作者提出的方法针对两个具体的工程实例计算了风振反应,并与日本规范公式及加拿大西安大略大学公式的计算结果作了对比。

A method for evaluating wind induced torsion vibration on high rise buildings is presented in this paper according to the theory of structure random vibrations. In the computation approach, the fluctuating pressure both in the along wind direction and the across wind direction are taken into account. The Davenport fluctuating velocity spectrum density function is adopted for evaluating fluctuating pressure SPF in the along wind direction, while the SPF for the fluctuating pressure in the across wind direction in the Japanese code is used as the SPF in the across wind direction. The results show that the tangent acceleration at the corner point is less than that in the wind blowing direction or in the across wind direction. The effect of the cross spectrum of the fluctuating pressure at different faces of the building is so small that it could be neglected at all. Evaluation work is carried out for a 68m building and a 180m building with this new method and the results are compared with those which are obtained from the Japanese method and Canadian method.