Seismic behaviour of high-rise frame-core tube structures considering dynamic soil–structure interaction

Abstract

As the population grows and land prices rise, high-rise buildings are becoming more and more common and popular in urban cities. The traditional high-rise building design method generally assumes the structure is fixed at the base because the influence of soil–structure interaction is considered to be beneficial to the response of structures under the earthquake excitation. However, recent earthquakes and studies indicated that SSI may exert detrimental effects on commonly used structural systems. In this study, a numerical soil–structure model is established in Abaqus software to explore the impacts of SSI on high-rise frame-core tube structures. The seismic response of frame-core tube structures with various structural heights, height–width ratios, foundation types and soil types is studied. The numerical simulation results including maximum lateral deflections, foundation rocking, inter-storey drifts and base shears of rigid-base and flexible-base buildings are discussed and compared. The results reveal the lateral displacement and inter-storey drifts of the superstructure can be amplified when SSI is taken into account, while the base shears are not necessarily reduced. Increasing the stiffness of the foundation and the subsoil can generally increase the seismic demand of structures. It has been concluded that it is neither safe nor economical to consider only the beneficial effects of SSI or to ignore them in structural design practice.