大型三面广告牌结构风荷载特性的风洞试验

Investigation of Wind Load Characteristics of Three-Plate Billboard Using Wind Tunnel Testing

针对三面广告牌这类特殊开敞的板式高耸结构,通过刚性模型的多点同步测压试验,考察了各风向作用下面板表面净风压分布的统计特征和正负风压极值的包络分布;针对面板支撑结构的抗风设计,给出了典型不利风向角下各面板的体形系数及其简化取值;并给出了面板结构的整体风力系数随风向角的变化规律。研究从面板连接、面板支撑体系、支撑立柱这三个层面,为三面广告牌风荷载取值提供了可靠的试验数据和计算依据。

With the rapid development of large outdoor billboards in recent years,their destruction resulted from the strong wind happen occasionally. A billboard is a typical wind-vulnerable high-rise structure with special open plates. The synchronous multi-pressure scanning measurement was conducted to the rigid model of a typical three-plate billboard. The statistical characteristics of net pressure distribution on the plates in different wind directions were comprehensively analyzed. Moreover,the envelop of the maximum positive and negative value of wind pressure in all wind directions are supplied and simplified. Furthermore,the shape factors of wind load distribution on the three plates and their simplified diagrams in most unfavorable wind directions were discussed and given. The change of wind force coefficients of overall three plates in different wind directions was analyzed as well. This paper provides basic data and wind load parameters for the wind resistant design of the plates and the supporting column of three-plate billboards.