大跨屋盖表面局部体型系数和峰值风压研究

Local shape factors and peak wind pressure of large-span roofs

基于大跨平屋盖和马鞍屋盖风洞测压试验,利用面积时程法得到全风向下屋盖最不利局部体型系数,并将计算结果与我国GB 50009—2012《建筑结构荷载规范》进行对比分析,同时采用Davenport峰值因子法、Hermite矩模型理论,分别计算高斯区、非高斯区峰值因子,得到屋盖表面最不利峰值风压。结果表明：我国GB 50009—2012中关于围护结构局部体型系数的规定不尽合理,在屋盖迎风前缘拐角区域明显低估了风吸力;对于迎风前缘中部区域,规定的局部体型系数过于保守;对于屋盖的中心区域,采用单一系数低估了迎风拐角区域与中心区域交界处的体型系数。为此,基于风洞试验和理论计算结果,参考日本AIJ-2004,对两类屋盖的全风向最不利局部体型系数和峰值风压系数进行了分区界定并给出相应的建议值。

Based on the wind tunnel experiment of the large-span fiat roof and saddle roof, the area time history method was adopted to get the most unfavorable shape factors, and the calculation results were analyzed according to the GB 50009--2012 ＇ Load code for the design of building structures＇. The Davenport crest factor method and the Hermit model theory were used to calculate the Gaussian and non-Gaussian peak factors respectively, and the most unfavorable peak wind pressure on the roof surface was obtained. Results show that the shape factors of the GB 50009--2012 on the cladding and components are not reasonable and the design wind loads of the front windward comer area is underestimated obviously. For the front windward central area, the shape factor is conservative; for the central area of the roof, a single coefficient is used to underestimate the shape factors at the junction of the windward comer and the central area. Therefore, based on the wind tunnel test and theoretical calculation results and also reference to the AIJ-2004 loading code, the most unfavorable shape factors and peak suction are defined by partition and the suggested values are also given.