开槽对大跨悬挑平屋盖结构风荷载的影响

Influence of Slot on the Wind Load for Large Span Cantilevered Flat Roof

本文结合一大跨悬挑平屋盖模型的风洞试验研究,分析了此类结构屋盖的平均局部体型系数和极值局部体型系数的分布特性;并根据其风压的分布特性,提出在悬挑屋盖承受较大负压的屋檐和角点附近这些遇强风易发生破坏的部位采取开槽气动抗风措施,进一步研究了该气动抗风措施对大跨悬挑平屋盖结构风荷载的影响.试验结果显示,它们可以有效地削减屋盖风敏感处的风荷载值,使平均局部体型系数大约降低50%,极值局部体型系数大约降低25%,所得的这些结果对于结构的抗风设计有一定的指导意义.

Based on the wind tunnel tests for large span cantilevered flat roof, the distributing characteristics of mean local shape factor and extreme local shape factor of the roof are studied. It has been found that the force of strong wind can cause the eaves and the corners of the roof to be destroyed by higher negative pressures. And according to the wind load distribution characteristics of the roof, an aerodynamic wind-resistant measure of making slots in these locations is proposed. The influence of slot on wind load of large span cantilevered flat roof are investigated. The experimental results show that the proposed method can make a reduction of 50% for mean local shape factor and 25% for extreme local shape factor in the wind-sensitive locations of the roof.