吉林火车站屋盖结构风荷载特性的试验研究

通过对吉林火车站的刚性模型风洞试验研究,得到在有无周边建筑群干扰下屋盖表面的平均风压系数、脉动风压系数以及屋盖的升力系数分布特性,同时对屋盖局部体型系数及结构风振响应进行详细的对比分析研究。研究结果表明:火车站屋盖结构表面主要呈现负风压(风吸力),屋盖合力升力系数均为负值。主站楼在迎风区屋檐、悬挑区域及屋面凸起的天窗位置气流分离较大,风压变化明显,出现较大的负风压系数;由于站台雨篷四周开敞,气流流经站台雨篷时较为顺畅,气流分离较小,因而站台雨篷风压系数较小。周边的干扰建筑整体上对屋面全风向局部体型系数有一定的遮挡效应,但也不能忽略部分区域增大的情况;周边建筑群对站台雨篷角部、主站楼凸起的天窗及东西两侧悬挑屋面区域风振响应影响较大。

EXPERIMENTAL INVESTIGATION ON WIND LOAD CHARACTERISTICS OF ROOF STRUCTURE FOR JILIN RAILWAY STATION

Based on the wind-tunnel test of rigid model of Jilin Railway Station,the mean and fluctuating pressure coefficients,the lift coefficients of the roof were presented and discussed with and without the surrounding buildings.Analyses of the characteristics of the local shape coefficient distributions and wind-induced responses were conducted.It was found that negative pressures(suctions) occurred on the railway station roof in general,the values of the lift coefficients of the roof were negative,and high negative pressure coefficients occurred on the eaves,cantilevered roof and the bulge part of the roof on the main station building.Relatively smaller suctions occurred on the platform awnings of the station because of open surrounding configurations there.The surrounding buildings have some shielding effect on the local shape coefficients of the roof,but can not ignore the situation where they are increased in some areas.Wind-induced responses were significant on the corner of platform awnings,cantilevered roof and the bulge part of the roof.The conclusions obtained from this study are expected to be useful in the wind-resistant design of long-span steel roof structures with complex shapes.