施工安全防护立网风速折减效应风洞试验技术研究

Study on Wind Tunnel Test Technology of Wind Speed Reduction Effect of Construction Safety Protection Net

通过采用STU-1风洞实验室低速试验段,对6种不同类型的安全防护立网:金属板面均匀布置大小一样的圆孔(A型);金属板面中间部分布置圆孔上下两部分布置楔形矩形孔(B型);金属板面两个方向交叉排列楔形矩形孔(C型);金属板面均匀单向排列楔形矩形孔(D型);金属板面以单元的形式均匀排列每25个圆孔组成的单元(E型);密目式安全网(F型);在5 m/s、12 m/s、15 m/s三种不同风速下进行风速折减测试研究。结果显示:金属材质安全防护立网刚性孔对风的流体压缩和分割效果更好,湍动能耗散更快,风速的折减效果远优于目前施工常用的聚乙烯料制作而成的密目式安全网;金属材质的安全防护立网圆孔型耗散来流动能的效果优于楔形矩形孔型,均匀布置大小一样的圆孔型优于以一定数量圆孔为单元均匀排列型;这6种类型安全防护立网风速折减系数大小依次为A型<E型<B型<D型<C型<F型。

By using the low-speed test section of STU-1 wind tunnel laboratory,six different types of safety protection nets are set up:round holes of the same size are uniformly arranged on the metal plate surface(type A);The middle part of the metal plate is arranged with a round hole;the upper and lower parts are arranged with a wedge-shaped rectangular hole(B type);The metal plate surface is arranged in two directions cross wedge-shaped rectangular holes(type C);Metal plate surface uniform unidirectional wedge-shaped rectangular hole(D type);The metal plate surface is evenly arranged in the form of cells consisting of every 25 round holes(type E);Close-mesh safety net(F type);Wind speed reduction tests were carried out at 5 m/s,12 m/s and 15 m/s.The results show that the rigid hole of metal safety protection net has better compression and segmentation effect on wind fluid,faster dissipation of turbulent kinetic energy,and the reduction effect of wind speed is far better than the dense mesh safety net made of polyethylene commonly used in construction at present.The effect of dissipated flow energy of metal net with circular pass is better than that of wedge rectangular pass,and the circular pass with uniform arrangement and the same size is better than that with a certain number of circular holes as units.The wind speed reduction coefficient of the six types of safety protection net is A<E<B<D<C<F.