COMPARISON OF VARIOUS ANALYTICAL METHODS FOR BUFFETING OF TALL BUILDINGS

Abstract

With the increase in population and land cost in large cities, the construction of tall buildings is becoming increasingly a necessity. Use of higher strength materials, improved capabilities in analysis and design and also in construction technology have lead to the construction of tall slender buildings of lighter density, thus making their aerodynamic stability an important concern. High rise buildings may oscillate excessively during wind storms because of dynamic effects of wind. Excessive drift may cause discomfort to the occupants and the building may even become unserviceable. The dynamic effects of wind are customarily represented by 'Gust Factors'. The velocity spectra • of longitudinal fluctuations is required for gust factor computation. Various authors have come up with different spectras. Some of these are dependent and others independent of height of building. In this dissertation spectras of Davenport, Kaimal, Harris and Simiu are being considered for gust factor and response computation. Apart from velocity spectra, there are other parameters also which are must to be considered. Important of these is alongwind crosscorrelation function, which correlates pressure fluctuation of windward and leeward side. Davenport and Vickery have assumed the pressures on both faces perfectly correlated, which is far from truth. Simiu on the other hand has considered this factor. In this dissertation various factors have been considered for computation of gust factors and responses by various methods and results compared.