Dynamic behaviour of tall buildings

Abstract

High-rise buildings in Sri Lanka are now becoming more popular, rapidly grmving. The ne~tional trend in Sri Lanka today is to construct tall buildings in city centres. (Wijeratanc am! Ja: asinghc. 1998). They are closely related to the city; and they are a natural response to dense population concentration, scarcity of land, and high land cost. However, tall buildings of the future ma\ \en \\CII be an integral part of one large building organism or the city. In terms of structural considerations, a building can be defined as ··High Rise"\\ hen its be he~\ iuur· itt terms of serviceability (i.e. deflection) and strength is governed by lateral loads (IVlendis am! Jayasinghc, 1996). The lateral loads are caused by either wind and/or earthquake. According to abm c definition. high-rise buildings arc in height range of I 0 to I 00 storeys or more. Lkvclopt11l.'11t in till· last decades has produced many slender buildings, demanding that particular attention be paid to their· complex behaviour under lateral loads. Actually, behaviour will become complex not only under the lateral loads, but also due to pure vertical loads which act eccentrically to the geometric centre of the structure. Apart from normal static loads acting on a structure, it is needed to anticipate some dynamic loads. According to importance of the structure, location and expected design life time. etc. the buildings should be able to withstand such dynamic loads.