Application of base isolation systems at plan irregular structures

Abstract

Application of base isolation systems is one of the possible solutions to avoid the negative effects from irregularity of structures in plan. In order to investigate the advantages of the application of these systems, a detailed evaluation of the behaviour of six spatial five storey structures with different level of plan irregularity and different shapes in plan was performed. All structures are analysed as fixed base and base isolated. At irregular structures with rectangular shape in plan, base isolation significantly reduces eccentricity between the centre of stiffness and the centre of mass. Oppositely, in structures with “T” shape, eccentricity is larger at base isolated models. The maximal interstorey drifts of base isolated models are about 2,5 times smaller in comparison with the fixed base.