Effects of corner modification on the Strouhal number of high-rise buildings under skewed wind

In recent years, the effectiveness of building corner modification measures in reducing wind loads on high-rise buildings has attracted great attention. The Strouhal number is a critical parameter in calculating the wind-induced response and equivalent static wind load of high-rise buildings in the across-wind direction. However, few studies have investigated the effects of corner modification on the Strouhal number of high-rise buildings under skewed wind conditions. Therefore, twenty-five models with different corner modifications were examined using high-frequency force balance (HFFB) wind tunnel tests in this study. Based on the experimental results, the base force coefficients and Strouhal number of the high-rise buildings with three types of corner modifications are discussed and compared with those of the square model. It was found that these three types of corner modifications are all effective in reducing the maximum mean and standard deviation of base force in the across-wind direction, with the reduction effect increasing as the corner modification rate increases. Three states of vortex shedding under specific corner modifications are identified by utilizing wavelet transformation. Formulas to evaluate the Strouhal number considering the effect of corner modification types and wind direction angles are fitted. The fitted formulas coincide well with the experiment data.