大跨度脊谷式膜屋盖风载分布的实验研究

基于台州某风雨操场脊谷式张拉膜屋盖缩尺模型风洞试验的数据结果,选取典型测点,研究了屋面迎风前缘、过渡区及中轴区的平均风压和脉动风压系数的分布特性。同时,鉴于屋盖的不规则曲面造型,表面风压梯度变化较大,采用单一体型系数反映屋面风载已不能满足要求。文中在结合屋盖自身复杂体型和风压分布特征基础上,按各榀各边片将屋面划分为不同区域,对5个不利风向角下的区域体型系数进行统计分析,并给出各区域体型系数建议取值。最后,针对这类体型屋盖特点和风压分布特性,得出一些结论和建议,为进一步研究该类屋盖的风荷载特性和结构抗风设计提供了依据。

Experimental Investigation on Wind Load Characteristics of Wave-shaped Membrane Roof

The results of experimental investigations in a reduced scale rigid model wind tunnel test on the wave-shaped membrane roof of a Taizhou gymnasium were described.Based on the test data,some typical measuring points were selected.The variations of mean and fluctuating wind pressure coefficients in the roof leading edge along the wind direction,intermediate region and central axial region were analyzed.Meanwhile,because of irregularly curved surface,wind pressure varies sharply in the whole region,a single shape factor could not express wind load!in the whole roof.By combining with complicated somatotype and pressure distribution characteristics,the whole surface was divided into different sub-regions.Corresponding sub-regional shape factors for five unfavorable wind directions were presented in detail.The suggested values of sub-regional shape factors were given.The maximum and minimum values of every measuring point irrespective of wind azimuths were also provided.The obtained conclusions and recommendations provide a better understanding on the intricate wind load response nature and structural wind resistance design for similar wind-sensitive projects.