大跨度屋盖结构的风荷载特征

分析了封闭型和敞开型两种大跨结构屋面风荷载的分布特征。对于封闭型,屋面的迎风区域由于受柱状涡和锥形涡的作用而产生极大的负风压,其他区域风压较小;对于敞开型,迎风时上下表面呈"上吸下顶"的风压叠加组合,背风时呈"上吸下吸"的风压抵消组合。同时讨论了附近的构筑物对屋面风荷载的气动干扰作用,在不同的风向下,干扰体与屋面的相对位置产生不同的干扰效果。

Characteristic of wind load on long-span roof

The two elementary categories of long-span roof,which are closed and open,are studied to decide the fundamental regularity of wind load on the roof by the wind tunnel tests on various roof shapes.As to the closed type,the windward region of the roof will suffer high suctions caused by cylindrical and conical vortices while the rest region suffer small wind load.As to the open type, the cantilevered canopy will suffer the most severe wind load with the combination of suction on upper surface and pushing on lower surface in windward direction.And in leeward direction the canopy will suffer small wind load due to the counteracting effect of suction on both surfaces.The influence of nearby interfering object to the roof is investigated.