不同断面宽度群体高层建筑的动力干扰效应(第1部分 顺风向响应)

基于高频底座力天平技术,研究了不同宽度比的两个和三个建筑物间的顺风向动力干扰效应。文中采用了神经网络、统计和谱分析等方法对干扰特性和机理进行了分析。结果显示,当受扰建筑位于上游施扰建筑物的尾流边界时,会产生较大的动力响应;并且两个施扰建筑物的联合干扰作用会比单个施扰建筑物的干扰作用强,在B类地貌下两个施扰建筑物测出的干扰因子(IF)会比单个施扰建筑的增加79%。位于上游的施扰建筑所脱落的旋涡会使受扰建筑产生涡激共振响应并且产生数倍于非共振情况的IF值,尤其对于小宽度的施扰建筑,在较小的折算风速时就会产生涡激共振问题。粗糙化地貌的高湍流度会对上游施扰建筑尾流的旋涡形成产生一定的抑制作用,在D类地貌下的IF值要远小于B类地貌情况,但在D类地貌下观察到IF值仍有2.2。

Wind-induced dynamic interference effects on different size tall buildings (Part I: Along-wind response)

Based on the high frequency force balance technique, systematical studies of the along wind dynamic interference effects on two and three tall buildings with different sizes were carried out. The interference characteristics and mechanism were analyzed by using artificial neural networks, statistics and spectrum analysis method. The results show that the increased turbulence intensity in the wakes of the upstream buildings has a tendency to increase the adverse effects on the downwind building, especially when the latter was situated near the wake boundary. Two upwind buildings can produce more adverse effects on the downwind building than a single building does. The tested maximum interference factor (IF) of two interfering buildings in exposure category B has an increasing of 79%over that of one building. Shedding vortices from the upstream interfering buildings, especially for a smaller breadth one, can lead to a vortex induced resonance and cause enhanced wind loads on the downstream building at lower wind speed. Generally, due to the fact that the higher turbulence flow disturbing the organized vortices and reducing the strength of the shedding vortices, the IF measured in the exposure category D are much smaller than those in exposure category B. However, the maximum IF is still found up to 2.2 in exposure category D.