Resilience-based methodologies for design of steel structures equipped with dissipative devices

In recent decades, numerous contributions have made it possible to implement seismic risk analysis in terms of resilience in order assessing direct and indirect losses both in a short and long-term perspective and in relation to the recovery capacity of buildings. Quantitative approaches to resilience typically require to extend the Performance Based Earthquake Engineering, PBEE, risk analysis framework introducing damage consequences for each relevant component (i.e. structural and non-structural elements, equipment) of the building layout in terms of recovery procedures and the respective times and economic and non-economic efforts. Resilience analysis methodologies can differ from each other for the level of information available in relation to the components of the building and the characterization of their seismic behavior. Refined analysis typically needs an amount of information hardly available in a short time, in which a simplified methodology based on less information required and less algorithm complexity can be more advantageous. The present work aims at investigating the effects of using two resilience analysis methodologies, based on different level of information, for the design optimization of a seismic dissipative system for office six-floor building with steel structure. Dissipative system consists in special braces-frames connections with replaceable energy dissipation elements (they are therefore called DRDs - Dissipative Replaceable Devices). Different structural solutions, defined from different geometrical and mechanical setting combination for devices, were considered. For both methodologies, simulation-based procedure were developed in order to collect best design solutions in terms of resilience behaviour. The two methodologies, named DEEP and RAPID, respectively the refined and the simplified ones, differ in the type of modelling, structural analysis, seismic input, damage models and consequences and extension of evaluable scenarios field. Although they are not completely and directly comparable due to the aforementioned differences, it has been possible to find similarities that confirm the mutual reliability of the two methodologies and give indications on their use.