Three dimensional dynamic response of tall buildings to stochastic wind

The formulation of the gust factor methods by Vickery, Davenport, Vellozi & Cohen, Solari, Simiu, the Danish Code, ESDU 85020, the ANSI Standards, and Greenway are compared. The differences in the gust factor formulations are attributed to the location and type of windspeed used in the along-wind velocity spectrum, the along-wind velocity spectrum, the correlation function, and the peak factor. The effect of these differences are evaluated via application to building types taken from a 1970 Vickery study. Large variation in the gust factors are shown to exist which illustrates that randomly choosing a method can provide misleading results. The best method to use depends on accuracy and ease of application. The ESDU method is very detailed and includes the latest refinements in spectral and length scales. Davenport's method as given in the 1990 National Building Code of Canada provides a time-efficient method with ease of application and results sufficiently accurate.;The computer program WIND models square or rectangular tall building response to gusty wind. The building response is comprised of displacements and accelerations in the along-wind, across-wind, and torsional directions. The buildings are square or rectangular with wind flowing normal to either the longer or shorter face. The along-wind force spectrum is based on an analytical development using the ESDU 85020 along-wind velocity spectrum and pressure coefficients derived from full-scale and model studies. The complexity of the across-wind force encourages the use of force spectra from wind tunnel studies. The across-wind force spectrum, the torsional moment spectrum, and the co-spectrum between across-wind force and torsional moment, are taken from the wind tunnel studies of Kareem; Saunders and Melbourne; and Islam, Ellingwood, and Corotis. These force spectra are represented by polynomial or linear functions and are included in the WIND program to model the various components of wind force. A spectral analysis of dynamic structural response is conducted within the WIND program.