Abstract:
Wind is a random movement of air particles in both time and space, which produces
very complicated dynamic loading scenario on flexible structures like tall buildings. Modern tall
buildings are becoming more slender, flexible, lightweight and irregular in shape due to revolution of
associated technologies. Consequently, analysis of tall buildings considering complicated nature of
wind loading and dynamic response of the structural system is an important role in design of tall
buildings. Wind tunnel test is the most reliable tool for the estimation of dynamic wind loading on tall
buildings. However, due to the cost and time involved, wind design codes are generally used during
the preliminary design stage. Thus, understanding the background of dynamic wind loading and
procedures adopted in wind design standards to represent the dynamic effects is vital to arrive at an
efficient, safe and economical structural system during the preliminary design stage. This paper
presents an overview on background of dynamic wind loadings and provisions of four international
wind codes frequently referred to in Sri Lanka, British Standard (BS), European Standard (BS EN),
Australian Standard (AS/NZS) and Standard of Architectural Institute of Japan (AIJ). Further, the
concept of equivalent static load derived based on the “gust-factor” method adopted in most of the
international wind design codes is discussed. At the end, a forty-six storied wall-frame structure was
used as the numerical example for the explanation of dynamic wind loading and its influence on the
structural design.
