A performance Comparison of Isolated, Dissipated and Fixed-Based Steel Buildings

The paper deals with comparative analyses of the seismic response of conventionally and innovatively protected steel buildings. A probabilistic characterization in terms of fragility curves of the relevant EDPs to be used within a general probabilistic assessment of the performances of framed steel structures having different earthquake-resistant systems is presented. Both conventional, moment resisting frames and concentrically braced frames, and innovative, base-isolated frames and dissipating braced frames, schemes are considered. The fragility curves represent a step of the knowledge data-base required for carrying out a full probabilistic methodology leading to an effective comparison of the performances of conventional and innovative protection systems accounting for the total costs of all the consequences to the expected seismic attacks. The direct examination of the fragility curves allows to make a rapid assessment of the performance of the different protection systems.