马鞍形屋盖风荷载研究

以某体育馆马鞍形屋盖为例,通过风洞模拟试验对马鞍形屋盖的风荷载规律和特性进行了研究,并且探讨了附属建筑对屋盖风荷载的影响。首先在风洞试验段中模拟了平均速度剖面为幂次律α=0.16的大气边界层气流,对缩尺比为1∶150的刚性测压模型进行了系统的风压分布试验,获得了在各种风向角下马鞍形屋盖时间平均脉动压力和瞬时脉动压力的分布规律,文中特别讨论了屋盖时间平均压力和瞬时脉动压力的特点和关系,对比了风洞试验直接获得的瞬时脉动压力和根据规范规定通过"阵风系数法"获得的相关结果之间的差别,指出了通过风洞模拟试验获得的瞬时脉动压力作为屋面(围护结构)风荷载设计依据的必要性。

Wind loading on saddle-backed roof

Wind loading on a saddle-backed roof of a stadium was conducted by means of wind tunnel testing.The effects of surrounding structures were investigated.An atmospheric boundary layer with mean wind speed profile of α=0.16 was simulated.Measurements of pressure distributions on a rigid model with scale ratio of 1∶150 were carried out.The characteristic of time-mean and fluctuating pressure distributions on the saddle-backed roof were obtained and their relationships were investigated and discussed.The fluctuating pressure obtained compared with which calculated from the code,by the means of 'gust factor',shows a quite difference due to the different mechanism of flow field.It indicates that it is necessary to perform a model wind tunnel test to obtain the reasonable fluctuating pressure data for the design of wind loading on enclosure structures.It is also helpful to other similar projects,as well as to future code establishment and modification.