ABSTRACT
Recently proposed “smart” base isolation strategies are shown herein to effectively protect structures against extreme earthquakes, without sacrificing performance during the more frequent, moderate seismic events. This base isolation system is composed of conventional low-damping elastomeric bearings and “smart” controllable (semiactive) dampers, such as magnetorheological fluid dampers. Simulation results comparing the performance of the “smart” isolation system to those for two lead-rubber bearing isolation systems are presented. The effectiveness of these isolation approaches are judged based on computed responses to several historical earthquakes scaled to various magnitudes. The limited performance of passive systems is revealed and the potential advantages of “smart” dampers are highlighted. To demonstrate the efficacy of the “smart” base isolation paradigm, results of an experimental study of a “smart”, base isolation system that employs magnetorheological (MR) dampers are presented.
