Simplified displacement demand prediction of tall asymmetric buildings subjected to long-distance earthquakes

Abstract

Large-magnitude long-distance earthquakes generated from Sumatra have significant potential engineering implications in Singapore and the Malaysian Peninsula due to accentuation by resonance in both the soil and buildings, and importantly, dynamic torsional amplification of elastic response of tall buildings. This paper introduces a simple asse ssment procedure which accounts for these amplification mechanisms particularly the effects on dynamic torsional coupling. In the proposed method, which is demonstrated with a typical 16-storey wall-frame building, the eccentricity and stiffness parameters of the equivalent single-storey building model were determined by calibrating its centre of rotation to match with that of the multi-storey building model. Despite the fact that the stiffness eccentricity in a wall-frame system is non-unique, a representative equivalent model can be identified by the method. The use of design charts developed from a parametric study of time-history analyses of single-storey models waives the requirement to conduct any such analyses on a case by case basis in practice. Thus, the proposed method only requires static analyses to be undertaken by the designer. The accuracy of the floor displacement and inter-storey drift demand predicted by the proposed procedure has been verified by comparison with results obtained from time-history analysis of the multi-storey building. However, there are discrepancies in the vertical distribution of inter-storey drifts between push-over analysis and time-history analysis. © 2004 Elsevier Ltd. All rights reserved.