邹鑫　汪之松　李正良

摘要：雷暴冲击风风场与大气边界层风场差异较大.为研究雷暴冲击风作用下高层建筑风荷载特性，采用静止型冲击射流装置模拟稳态雷暴冲击风风场，进行高层建筑刚性模型测压试验，讨论了不同径向位置处高层建筑局部和整体风荷载时域和频域特性.结果表明：建筑表面平均风压最大值出现的位置与径向风速峰值一致.同时，迎风面风压最大值出现在底部，明显不同于大气边界层风场中最大值靠近顶部位置的风压分布特性；径向层风荷载均值最大值出现在建筑中部，横风向和扭转向层风荷载均值为0.径向和横风向层风荷载谱沿高度不变，而扭转向层风荷载谱沿高度变化明显.

关键词：冲击射流模型；高层建筑；刚性模型；风荷载特性；雷暴冲击风

中图分类号：TU312.1； TU973.32 文献标识码：A

Abstract：Downbursts are dramatically different from the atmospheric boundary layer. To investigate the wind load characteristics of highrise building in thunderstorm downbursts， a static impinging jet was used to simulate the thunderstorm downburst. Rigid model manomeric test was carried on a highrise building. Both local and overall wind load characteristics were discussed in time domain and frequency domain. The results indicate that the position of the maximum mean surface pressure is consistent with the peak radial velocity. Meanwhile， the maximum surface pressure on the windward side is located at the bottom of the building， obviously different from the top part tested in atmospheric boundary layer wind field. The maximum mean radial wind load of each layer is located at the middle of the building. And the mean wind load is 0 at the crosswind and torsional direction. Wind load spectrums of each layer keep unchanged along the height at the radial and crosswind direction. But wind load spectrums changes obviously at the twist direction.

Key words： impinging jet model； highrise building； rigid mode； wind load characteristic； thunderstorm downburst

目前结构抗风设计一般依照大气边界层风场进行，对建筑结构风荷载特性的研究也主要集中在边界层风场作用下[1-2].然而根据相关统计资料[3]，一个地区的极值风速往往不是由大气边界层风场决定的，而是产生于雷暴冲击风等极端天气气候.因此，对雷暴冲击风作用下建筑风荷载特性的研究显得尤为重要.

近几十年来，国内外学者对雷暴冲击风的研究着重于风场特性方面[4-8]，对建筑结构风荷载特性的研究相对较少.Letchford和Chay[9-10]分别测试了静止型冲击射流风场和运动型冲击射流风场中，小立方体表面压力分布.陈勇[11-12]对球壳……