大跨度悬挑曲面屋盖结构风洞试验研究

Wind Tunnel Test Study on Large-span Cantilevered Curved Roof

大跨度悬挑曲面屋盖结构属于风荷载敏感结构,又因其造型独特,风荷载特性复杂,故其抗风设计尤为重要。通过对青岛西站铁路站房进行1/200缩尺比的同步多点刚性模型测压风洞试验,系统分析了大跨度悬挑曲面屋盖在不同风向角下的平均压力系数分布规律及50年重现期极值压力统计值分布规律,并基于此数据分析屋盖体型变化对风压分布的影响。结果表明:屋盖整体呈现负压力;屋盖风压分布受风向角、屋盖体型的影响明显,在不同风向角下,屋盖体型对风压分布的影响程度不同;屋盖的挑檐、边角及屋脊处的平均压力系数绝对值要比其他区域大;站房表面极值压力绝对值最大值达4.4kN/m^(2),主要分布于站房的挑檐部分,因此在设计时需着重考虑挑檐的抗风设计。

The large-span cantilevered curved roof structure is a wind load sensitive structure,and its wind resistance design is particularly important because of its unique shape and complex wind load characteristics.Through the wind tunnel test of the railway station building of Qingdaoxi Railway Station,with a 1/200 scale synchronous multi-point rigid model for pressure measurement,the distribution pattern of the average pressure coefficient of the large-span cantilevered curved roof under different wind direction angles and distribution pattern of statistical extreme pressure in the 50-year return period were systematically analyzed.Based on this data,the influence of roof shape change on wind pressure distribution was analyzed.The results show that the overall roof presents negative pressure,and the wind pressure distribution of the roof is obviously affected by the wind direction angle.Under different wind direction angles,the roof shape has different influence on the wind pressure distribution.The absolute value of the average pressure coefficient at the eaves,corners and ridges of the roof is larger than that in other areas.The maximum absolute value of the extreme pressure on the surface of the station building,up to 4.4 kN/m^(2),is mainly distributed in the overhanging part of the station building.So,it is necessary to focus on the overhanging eaves in the wind resistance design.