某大型焰火网幕风荷载体型系数试验研究

Experimental study on shape factor of wind load for a large net curtain with fireworks

某晚会焰火网幕宽90m,高25m,共有4幅,为确定巨型网幕的风荷载体型系数,采用局部实物模型风洞实验测力的方法,分别测试了单层网幕和被测网幕前布置1、2层网幕,网幕后布置1层网幕时,该网幕的风荷载体型系数以及不同风向角对体型系数的影响。结果表明:单层焰火网幕的风荷载体型系数为0.17;随着前置网幕层数的增加,网幕风荷载体型系数减小,前置1层、2层网幕时被测网幕的体型系数分别为0.14、0.11;后置网幕对体型系数影响较小;风向角在0°~22.5°之间时,单层网幕风荷载体型系数不变,风向角增大到45°时,体型系数减小为0.10。试验结果为某焰火网幕装置的抗风设计提供了基础数据,可为同类结构风荷载计算提供参考。

There are 4 net curtains with fireworks in National Day Gala,which are 90 m wide and 25 m high.In order to obtain the shape factor of wind load of the curtain,the wind tunnel test method of local physical model is used to test the force of single layer curtain.Influence of the shape factor of single-layer net curtain and different wind direction angles on the shape factor are tested.The wind load shape factor of the net curtain with 1 or 2 layers in front of the curtain and 1 layer behind it is also tested.Results have shown that the shape factor of wind load of single-layer net curtain with fireworks is 0.17;with the increase of the number of layers of front curtain,the shape factor of measured curtain is 0.14 and 0.11,respectively,when the front curtain is 1 and 2 layers;when the wind angle is 0°~22.5°,the shape factor of wind load of single-layer curtain remains unchanged.The wind angle increases to 45°,the shape factor decreases to 0.10.The experimental results may provide basic data for the wind resistance design of a fireworks net curtain device,and can provide reference for wind load calculation of similar structures.