沿海地区索结构体育馆风洞试验与群风效应研究

Research on wind tunnel test and group wind effect of cable structure gymnasium in coastal area

针对两类屋面型式(上凸型和下凹型)、四种屋盖结构(单层马鞍形索网、轮辐式双层索网、索穹顶、弦支穹顶),设计制作了缩尺比分别为1∶250、1∶200两个试验模型,在B类地貌下开展了60组模型风洞试验,探究了全风向角下两类屋盖结构的风压峰值分布规律,分析了不同风向角、邻近建筑对目标建筑物风压特性的影响规律。结果表明:全风向角下来流方向无邻近建筑影响时,两类屋盖迎风面区域的负风压峰值最大,分别较上凸型和下凹型屋盖中间区域的负风压峰值高约3.0、1.5倍;屋盖中间区域风压峰值分布均匀,以承载负风压为主,仅下凹型屋盖中部出现正风压;风向角对屋盖风压分布的影响主要体现邻近建筑物的干扰上,其对屋盖平均和脉动风压系数的影响以来流方向无邻近建筑时最大、来流方向有邻近建筑时次之、尾流方向有邻近建筑物时最小;屋盖迎风面测点风压概率分布具有明显的非高斯特征,存在极大负压值,而屋盖中间和尾流区域的测点风压具有典型的正态分布特征。

For two types of roofs(upper convex and concave),four roof structures(single-layer saddle-shaped cable net,spoke-type double-layer cable net,cable dome,string-supported dome),two test models with scale ratios of 1:250 and 1:200 were designed and produced,and 60 sets of model wind tunnel tests were carried out under category B landforms,and distribution law of wind pressure peaks of the two types of roof structures under the full wind direction were explored.The influence law of different wind angles and neighboring buildings on the wind pressure characteristics of target buildings was analyzed.The results show that the peak of negative wind pressure on the windward side of the two types of roofs is the largest,when there is no influence from neighboring buildings in the downflow direction of the full wind angle,which is about 3.0 times and 1.5 times higher than that in the middle area of the upper convex and concave roofs respectively.Wind pressure peak in the middle area of the roof is evenly distributed,and the negative wind pressure is the main load,and only the positive wind pressure appears in the middle of the concave roof.Wind direction angle is opposite to the roof.The influence of wind pressure distribution is mainly reflected in the interference of adjacent buildings.Its influence on the average roof and fluctuating wind pressure coefficient is the largest when the flow direction is not adjacent to the building,the flow direction is second when the flow direction is adjacent to the building,and the wake direction is close.The probability distribution of wind pressure at the point of roof upwind has obvious non Gaussian characteristics and has a maximum negative pressure value.The wind pressure distribution of the middle and tail points has typical normal distribution characteristics.