Experimental Investigation of Blockage Effects on Mean Wind Forces on Tall Buildings in Uniform Flow

Abstract:

Blockage effects of single rectangular tall building were investigated by Commonwealth Advisory Aeronautical Research Council (CAARC) Standard Tall Building Model in the TJ 2 Boundary Layer Wind Tunnel in Tongji University. The wind pressure tests of rigid models whose blockage ratios were 4.1%, 6.1%, 8.4% and 10.1% were carried out in the uniform flow. The blockage effects on mean wind force characteristics of model was emphasized. The results show that in the uniform flow, mean drag coefficient of each layer increases with the increasing of blockage ratio, while the distribution of drag coefficient along the height of buildings changes little. Along wind mean base bending moment coefficient of buildings also increases with the increasing of blockage ratio. Finally, new correction formula of blockage effect of mean drag coefficient and along wind mean base bending moment coefficient were put forward based on the wind tunnel test results.