群集建筑中大跨裙摆屋盖风荷载特性的数值模拟研究

以苏州太平金融大厦为工程背景,针对其大跨裙摆屋盖的风荷载作用,首先采用RNG k-ε模型模拟分析了其平均风压分布规律,以及风向变化对屋盖表面风荷载体型系数的影响;其次,引入干扰因子IF,探讨了周边建筑对大跨裙摆屋盖风荷载的气动干扰作用。结果表明:0°风向下,走廊上方屋盖两侧区域出现“上吸下顶”的叠加作用;90°风向下屋盖北侧飘带末端区域受到狭道风效应出现正压集中现象;风向变化对大跨裙摆屋盖的风荷载体型系数分布影响较大;且周围建筑物对大跨裙摆屋盖的气动干扰效应明显,主要表现为风压“遮挡效应”,而局部区域表现为风压“放大效应”。

Numerical simulation of wind load characteristics on long-span skirted roof in cluster buildings

Taking Suzhou Taiping Finance Building as the engineering background,for its special long-span skirted roof,the RNG k-εmodel is firstly used to simulate and analyze the influence of the mean wind pressure distribution law and wind direction variation to the wind load shape coefficient on the roof surface.Secondly,the interference factor IF is introduced to study the aerodynamic interference of the surrounding buildings on the long-span skirted roof.Studies show that:the wind pressures on the upper and lower surfaces on both sides of the rear of the long-span skirted roof have superimposing effects under 0°wind direction angle,there is a positive pressure concentration due to the narrow wind effect on the edge of the north skirted side of the roof under 90°wind direction angle,so the wind direction angle has a great influence on wind load shape coefficient of long-span skirted roof.The aerodynamic interference effects of the surrounding buildings to the long-span skirted roof are obvious,mainly manifested as the“shielding effect”of the wind pressure,while the local area shows the“magnification effect”of the wind pressure.