复杂体型超高层建筑风压脉动特性

Fluctuating character investigation on wind pressure of high-rise building with complex shape

为研究超高层建筑顺风向和横风向脉动风压功率谱的变化规律,以某X型超高层建筑为工程背景,进行刚性模型测压风洞试验.利用Tamura等基于准定常假定提出的由顺风向脉动风速谱转化得到顺风向脉动风压谱的方法将Davenport和Kaimal风速谱转化为脉动风压谱,并将两者得到的风压谱与试验结果进行了对比;利用Ohkuma等提出的矩形建筑横风向风荷载功率谱的数学模型来拟合侧风面测点脉动风压谱,结果能够与试验很好的吻合.分析了相同高度处各测点之间以及不同高度测点层各测点脉动风压之间的相关性;最后研究了测点风压的水平和竖向相干性,并利用基于单参数最小二乘算法的计算程序对测点空间相干函数曲线进行拟合,结果与风洞试验吻合较好.

The wind tunnel test of a tall building with X shape was carried out and the power spectrum for alongwind and acrosswind wind pressure of this building was studied. Power spectrum for wind velocity： of Davenport and Kaimal were converted to that for fluctuating wind pressure according to the method proposed by Tamura, etc. Wind pressure of the test point on side wind surface was fitted according to the mathematical model aimed at rectangular tall buildings proposed by Ohkuma. The fitted power spectrum density Curve of wind pressure in alongwind and acrosswind direction was compared with test data. Horizontal and vertical correlation relationships among wind pressures of different test points were analyzed. Horizontal and vertical co- herence features of fluctuating wind pressures were investigated and the coherence curve was fitted based on the least squares procedure for single parameter. The fitted coherence curve agrees well with the wind tunnel test.