摘要
建筑立墙迎风面开孔时内部风压随开口处外压变化显著,使得屋盖所受净压显著增大,其测量值往往大于规范取值。而对于屋盖顶部开孔的建筑,其内部风荷载我国规范没有相应取值。为了进行开合屋盖结构设计和探讨屋盖顶部开孔对屋盖风荷载变化的影响,以1∶300的几何缩尺比制作了一个开合屋顶体育场的刚性模型,在B类地貌中对该体育场固定、活动屋盖的上、下表面进行了风洞测压试验,得到了屋盖上、下表面的体型系数、平均风压系数、脉动风压系数和极值风压系数。试验结果表明:活动屋盖的开启,可有效减小固定屋盖和活动屋盖的平均风荷载,引发整个结构承受向下的风荷载;活动屋盖开启将增大固定屋盖和活动屋盖的净脉动风荷载;活动屋盖开启将减小固定屋盖和活动屋盖的极小值风荷载,且固定屋盖上的最大极小值风压系数的位置往屋顶开口方向移动。
In the case of a building with a dominant windward opening,the internal pressure closely follows the external pressure at the opening,and the net roof pressures will be increased significantly which were normally larger than those derived from some codes.Currently for the structures with openings on the roofs,the internal wind pressure values were not provided in Chinese code.For the aim of structural designing as well as for the purpose of studying the effects of the wind loads on the main roof with retractable roof＇s opening,a rigid test model of a stadium with retractable roof was built with geometrical scale of 1∶300.Wind tunnel tests were carried out to measure the wind pressures on the fixed roof and the retractable roof in turbulence flow.The characteristics of shape coefficient,mean wind pressure coefficient,fluctuating wind pressure coefficient and extreme wind pressure coefficients on the fixed roof and retractable roof were particularly studied.It is shown that retractable roof＇s opening reduces the mean wind loads on both the fixed and retractable roof greatly,and will make the main roof experienced positive pressures.In the case of retractable roof opening,the fluctuating wind loads of the fixed roof and retractable roof are increased,which compared to that of the closed case.For the retractable roof in opened condition,the extreme wind loads on both fixed and retractable roof will be decreased,and the maximum extreme wind loads will be present at the top opening of the fixed roof.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2010年第10期17-23,共7页
Journal of Building Structures
基金
国家自然科学基金项目(50708035)
中国博士后科学基金项目(20060400873)
关键词
大跨度钢结构
活动屋盖
风洞试验
风压系数
体型系数
large-span steel structure
retractable roof
wind tunnel test
wind pressure coefficient
shape coefficient
