大跨叠合曲面屋盖风荷载分布特性研究

Study of Wind-load Distribution Characteristics of a Large Span Superimposing Curved Roof

为探讨复杂形状大跨屋盖结构表面的风荷载变化特点,采用同步测压风洞试验方法,对杭州亚运轮滑馆大跨叠合曲面屋盖的表面风压分布特性进行了研究。考察了不同部位平均风压的分布规律,获得了不同区域的分区体型系数,可供屋盖承重结构抗风设计使用;探讨了不利风向角下极值风压的变化特点,得到了全风向角下屋盖极值风压的等值线图,可供围护结构设计使用。结果表明,屋盖平均和极值负风压的不利值主要出现在东北或西南斜风作用下的中部鞍型屋面迎风前缘,以及两侧环绕屋面尾部与另一侧屋面叠合处,其原因与曲面叠合形成局部狭道效应加剧气流分离等因素有关。

In order to explore the variation features of wind loads on the surface of large span complex-shaped roof structures,wind pressure distribution characteristics of the roof of Hangzhou Asian Games Roller Skating Stadium,a large span superimposing curved roof have been investigated using the simultaneous pressure measurement wind tunnel test technique.The distribution rules of the mean wind pressure on different roof areas are examined,and the partition shape coefficients at different sub-regions are presented,which can be used for wind resistant design of the roof load-bearing structure.The variation characteristics of the extreme wind pressure under unfavorable wind directions are also discussed,while the extreme wind pressure contour under full-direction wind is gained which is applicable for design of the roof envelope structure.The results indicate that the unfavorable values of the mean and extreme negative wind pressure mostly appear at the windward leading edges of the middle saddleback roof and the tail parts of the two-side surrounding roofs superimposing with the other side one,under north-eastern or south-western oblique wind.The reason is related to the local narrow channel effect imposed by the superimposing curves,leading to acceleration of flow separations.