湍流对高层建筑风压幅值特性影响的研究

Research of turbulent effects on characteristics of wind pressure amplitude on tall buildings

风荷载是高层建筑设计的控制荷载之一,来流湍流对结构风荷载分布和风致响应有很大的影响,研究来流湍流对高层建筑风荷载的影响有很重要的实际意义。本文主要研究来流湍流强度对高层建筑风压幅值特性的影响。为形成不同的湍流强度,本文采用风洞试验的方法,共模拟了五种风场,对2种不同断面相同高度共2个模型进行了研究。结果表明,当湍流强度比我国D类风场的湍流强度明显增大时,模型的四个侧面的平均风压系数在数值上是增大的,但是在背风面和侧面的平均风压系数绝对值是减小的;在D+风场中,背风面和侧风面出现了小正压。特别是背风面平均风压系数增加量比迎风面前后对应位置增加量更大,从而使整个结构所受的平均风阻力减小。高湍流强度对高层建筑表面风压有明显影响(如小正压),可为高层建筑抗风设计提供参考。

Wind load is one of the controlling loads for structure design of tall buildings,the turbulence intensity of incoming flow has great influence on both the surface distribution of wind load and wind-induced response,so it is very important to study that influence. In order to research the turbulent effect on characteristics of wind pressure amplitude on tall buildings,there were simulated 5 different flows in a wind tunnel to investigate 2 models. The results show that the mean wind pressure coefficients on all sides of the model become larger when turbulence intensity is much larger than it in terrain category D. A little positive pressure occurs on the side and backward surface in flow D ＋. Especially,the mean pressure of the leeward surface increased greater than the windward so as to reduce the drag of the body. High turbulence intensity has obvious influence on the surface pressure（ such as a litter positive pressure）,which can be used as reference for the wind-resistant design of tall buildings.