Wind Pressures on Buildings-Probability Densities

By use of available statistics of building sites describing wind magnitude and direction, calculation of the recurrence interval for peak pressures may be performed if the probability distribution of pressure fluctuations is assumed, e.g., a Gaussian distribution. To perform the analysis adequately, the statistics of pressure fluctuations and their relationship to the governing physical parameters must be known. Fluctuating pressure data have been obtained on a scale model of an actual structure placed in a wind tunnel which simulated the characteristics of the atmospheric wind. The data were analyzed to obtain the probability distribution of the pressure fluctuations. The results show a remarkable similarity in probability distribution for large areas of the structure. In regions of positive pressure, the pressure distribution can be represented adequately by a Gaussian relationship. In regions of negative pressure, deviations from a Gaussian distribution are significant and can lead to a substantial underestimation of peak pressures if that distribution were assumed.