海边坡角可调试验房风荷载现场实测研究

Field investigation on wind loads of a low building with adjustable roof pitch near sea

在东海边上海浦东国际机场附近建造了一栋坡角可调的低矮房屋及测风塔,以对海边附近的风场特性及低矮建筑屋盖表面风压特性进行研究。该变坡房最大特点是屋盖坡角可以在0°～30°之间自由调节,以便分析坡角变化对屋盖表面风压的影响。首先分别对0°、10°及20°屋盖坡角下选取的10分钟风压时程信号进行了分析,并与1:30刚性测压风洞试验相应结果进行了对比,表明屋盖表面平均及脉动风压分布与风洞试验结果吻合较好。其次,对风速、风向角的平稳性及其之间的相关性进行了分析,说明风速与风向角之间耦合作用明显,尤其竖向风向角对风速脉动影响较大,时间滞后为0时两者之间相关系数接近-0.5。最后,对屋盖表面风压信号的非高斯特性进行了研究,发现偏度与峰度之间具有较好的线性关系,并给出了0°、10°及20°屋盖坡角下偏度与峰度的线性拟合公式。

A low building and a tower were constructed near Shanghai Pudong International Airport by east china sea in order to investigate characteristic of wind field and wind pressure on the roof surface of the low building. The remarkable feature of the low building was that its roof pitch can be adjusted between 0°and 30°, so that the impact of different roof pitches on the wind pressure of the roof can be analyzed. Firstly, three ten-minute wind pressure time- histories with different roof pitches of 0°, 10°and 20° were analyzed, respectively. And then comparison was made with the wind tunnel test data of a rigid model with 1 ： 30 scale. It was shown that the distributions of the mean pressure and the fluctuating one agree well with the wind tunnel test results. Next, the stationarity of wind velocity and wind direction angle and the correlation between them were analyzed. It was discovered that the coupling effect between them is evident; the impact of the vertical wind direction angle on fluctuating wind velocity is large ; the correlation coefficient is about -0.5 without time delay. Finally, the non-Gaussian characteristic of the wind pressure was investigated. It was shown that there exists a linear relation between skewness and kurtosis, and the fitting formulas for skewness and kurtosis are presented with 0°, 10°, and 30° roof pitches.