圆角化方形截面高层建筑风荷载特性试验

Experiment on Characteristics of Wind Loads of High-rise Building with Rounded Square Section

对圆角率为25%的正方形高层建筑刚性模型进行了测压试验,并对其风荷载特性进行了研究;分析了三分力系数和基底力矩系数随风向角的变化规律,给出了阻力系数平均值、根方差值和升力系数根方差值拟合结果;分析了最不利风向角下的风荷载功率谱,并采用经验公式进行拟合;分析了体型系数并与规范中正方形体型系数进行了对比。结果表明:对正方形建筑角部进行圆角化处理能明显降低建筑风荷载,且消除了功率谱曲线谱峰尖而窄的单峰现象,从本质上改变风荷载特性,有利于主体结构的抗风设计;角部区域负压较大,对幕墙抗风设计不利。

The pressure test was carried out on the rigid model of square section high-rise building with round corner rate of 25 %, and the characteristics of wind loads were studied. The change rules of three-component coefficient and base moment coefficient along with the wind angle were analyzed. The fitting results of mean value of drag coefficient, root square deviation of drag coefficient and lift coefficient were given. The wind load power spectrum under the most unfavorable wind angle was analyzed, and fitted by empirical formula. The shape coefficient was analyzed and compared with the square shape coefficient of code. The results show that the wind load can be significantly reduced when the corners of square building are rounded, and the sharp and narrow single peak phenomenon of the power spectrum curve can be eliminated. The wind load characteristic is changed in essence, and is beneficial for the wind resistant design of the main structure. The negative pressure in the corner area is larger, which is disadvantageous to the wind resistance design of curtain wall.