低矮房屋在风灾中首先是围护结构的破坏,因此对于低矮房屋抗风性能的改进,最为有效的方法是减小屋面的极值风压.根据我国东南沿海农村住宅的调研报告,并结合浙江省民用建筑图集,8种适用于我国东南沿海农村居民低矮房屋建筑的檐口形状(包括各种檐沟或挑檐)在TJ-2风洞试验室进行了缩尺模型测压试验.研究发现,对于3种具有不同坡度的双坡屋面低矮房屋,这些形状各异且具有附属构造的檐口的出现,抑制了迎风向来流的分离和再附,从而减小了迎风向屋面前沿区域的负风压值；对于减小的幅度而言,拥有26.6°和33.7°坡角的坡屋面要比拥有14.0°坡角的双坡屋面小得多；对于8种檐口而言,具有檐沟、悬挑盖板和竖直挡板的檐口表现出了优异的抗风性能,对最不利面积极值风压的影响,折减幅度可以达到47％以上.%For low-rise buildings, their components and cladding are usually destroyed firstly in wind disasters, so the most effective wind-resist method is to reduce the extreme wind pressure on roofs. According to the investigation report of rural houses in southeast coastal area of China and the drawing collections of civil houses in Zhejiang province, 8 kinds of eave shapes including various configuration details of eave gutters and overhang eaves were designed and tested in the TJ-2 wind tunnel laboratory to study effects of eave shapes on wind loads of gable-roof low-rise buildings with 3 kinds of roof pitches. It was shown that due to presence of attached eave configurations, the flow separation is suppressed and the suctions on the roof% windward edge area are reduced; the reduction level of wind loads on house roofs with 26.6° and 33. 7° roof pitches is much smaller than that of wind load on house roof with 14. 0° pitch; the eave configuration No. 3 and No. 8 designed by the authors have the best effect, they can reduce the worst area-averaged extreme wind pressure up to 47% or more.
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