Assessment and dynamic nonlinear analysis of different base isolation systems for a multi-storey RC building irregular in plan

In the present paper two base isolation systems are analyzed and their seismic behavior is compared with reference to a multi-storey reinforced concrete building. The base isolation systems have been designed in compliance to the European seismic codes EC2 and EC8. A base isolated building is adopted which is characterized by strong irregularity in plan. A comparative analysis is presented for evaluating the behavior of the structure subject to seismic events. Two base isolation systems have been considered in the analysis, the High Damping Rubber Bearing (HDRB) actuated in parallel with a Friction Slider (FS) and the Lead Rubber Bearing (LRB) also actuated in parallel with a Friction Slider (FS). A dynamic nonlinear analysis is performed for the three-dimensional base isolated structure. Recorded accelerograms for bi-directional ground motions compatible with the reference elastic response spectrum have been used for the evaluation of the seismic response of the structure. The seismic assessment and the dynamic nonlinear analysis of the base isolated structure are illustrated by presenting a comparative analysis of the behavior of the structure isolated by the two considered base isolation systems and the corresponding behavior of the traditional fixed base structure.