Comparisons of Aerodynamic Data with the Main Wind Force–Resisting System Provisions of ASCE 7-16. II: Mid- and High-Rise Buildings

Abstract

The purpose of this study is to investigate the effects of building geometry on tall-building aerodynamics, accompanying the analysis for low-rise buildings found in the companion paper. Aerodynamic data for total of 30 rectangular-plan buildings were obtained in wind tunnel experiments. This work tested building configurations with plan aspect ratios, L/B (where L is the horizontal dimension parallel to the wind and B is the across-wind dimension) ranging from 0.25 to 4 and height ratios, H/W (where H is roof height and W is the least horizontal dimension) ranging from 1 to 12. Additionally, this work made systematical comparisons with wind load provisions in Chapter 27 of ASCE 7-16. Buildings with ratios of H/W>∼4 have aerodynamic coefficients that are approximately constant, which means that this can be a practical aerodynamic definition of high-rise buildings. There is continuous variation of the aerodynamic coefficients for H/W<4 such that differentiation of mid-rise and low-rise buildings may be considered as arbitrary from an aerodynamics perspective. Wind load coefficients for mid-rise buildings are observed to be lower than for high-rise buildings. However, for both mid-rise and high-rise buildings, largest load coefficients are observed for L/B∼0.67. The plan ratio of L/B captures the variation of the load coefficients for high-rise buildings. For lower buildings, both L/B and H/W ratios are needed to define the wind loads.