Seismic response reduction of high rise steel-concrete composite buildings equipped with base isolation system

Abstract

This study presents the effectiveness of the high-rise multi-storey buildings in reducing the seismic response induced during the earthquake events with the implementation of the Base Isolation system. For this, two base-isolated steel–concrete buildings are considered for the analysis having twelve and fifteen storey levels. The lead rubber bearing isolators are used for providing the base isolation system for these buildings. For the sake of comparison of the seismic responses of composite base-isolated buildings, their fixed base Reinforced Concrete and Composite counterparts are also modelled. The Seismic responses are evaluated by performing the response spectrum method for the highest seismic zone as per Indian Code. The results of the study indicate that that base isolation provided with the lead rubber bearing isolators is effective in reducing the overall seismic responses of the composite buildings in the range of 50% - 60%. The effectiveness of the base isolation is more in the case of 15 storeyed building. The reduction of approximately 50% is found in the storey drift and displacements of the base isolated composite building in comparison to reinforced concrete building.