Performance based seismic design of reinforced concrete base isolated buildings

Abstract

Base isolation systems are innovative techniques for the passive control of structures. In this paper a base isolation system is used for the seismic protection of a reinforced concrete building that is highly irregular in plan. A comparative analysis with the same building designed with a fixed base enables clarification of the advantages of the base isolation technique with regards to the seismic behavior of the structure. Dynamic nonlinear analyses are performed according to the European code and the Italian code for evaluating the seismic response of the fixed base and the base isolated reinforced concrete buildings. By adopting the strategy of the shift of the natural period of vibration for the base isolated structure, a base isolation system has been designed by analyzing a hybrid solution realized by elastomeric isolators placed in parallel with friction sliders. The verification of structure is carried out and some considerations of the advantages of base isolation techniques are described with reference to European and Italian seismic codes.