Effects of gust load on tall buildings

Abstract

With the rapid growth in building construction and urbanization in India, buildings are getting taller than ever. As the height of building increases it becomes more flexible. The structure of high-rise buildings is usually more sensitive to effects of wind. The wind pressures are fluctuating in nature and thus there is possibility of the fundamental natural frequency of the structure matching the wind frequency. The gust effectiveness factor method of IS: 875 (Part 3) – 1987 takes into account the dynamic properties of the structure, the wind-structure interaction and then determines the wind loads as equivalent static loads. In the present project work, square and rectangular buildings of 30, 40 and 50 storeys are considered for wind load analysis. Equivalent static wind load is calculated using provisions of IS: 875 (Part 3) – 1987. The structures are analysed using CSI ETABs 2015 for maximum storey displacement, storey drift and storey shear. Comparison is made between structures loaded under static wind load and equivalent static gust load.