Size Reduction Factor of Extreme Area-Averaging Wind Pressure on Claddings of High-Rise Buildings with Rectangular Section

Abstract:

By conducting a series of wind pressure measurement wind tunnel tests， the characteristics of the extreme area-averaging wind pressures on the cladding of a building with a rectangular cross-section were studied. The test results were compared with relevant standards of Load Code for the Design of Building Structures （GB 50009—2012）. The influence of areal size， horizontal scale and vertical scale of forced areas were discussed， and more reasonable scale parameters were suggested for size reduction coefficients （SRCs） of area-averaging wind pressure. The results indicate that extreme wind pressure gradually declines with the size of forced areas increasing. When the full-scale area reaches about 50 m2， the SRC of positive extreme area-averaging wind pressure is close to about 0.9， while that of negative extreme area-averaging wind pressure is close to about 0.8. The wind-load reduction method of building structure load code in China will lead to an underestimation of wind pressure extreme value， especially in the most unfavorable positive pressure. It is not appropriate to describe the variation of the reduction coefficient by taking the area of acting surface as the size parameter. It is，therefore， suggested that comprehensive size parameters， b0.85h0.15/B， of the horizontal dimension， b， vertical dimension， h， of the acting surface and the width， B， of the windward surface of the whole building be used to determine the SRCs of the surface wind pressure extremum of the cladding.