Seismic design of a multi-story steel building with moment resisting frames using prequalified earthquake haunched joints

The current master thesis presents the design of a high ductility steel multi-storey building located in L’Aquila, which is one of the Italian regions with the highest seismic hazard. The structure is a moment resisting frame system (MRFs), which presents a large capacity to exhibit large deformations in inelastic field without significant reduction in strength. In addition to support gravity and wind loads, the structure has been designed using the capacity design method in order to resist frequent and rare seismic actions. Besides using steel profiles, composite steel-concrete cross-sections have been used owing to the several advantages that present in terms of strength and stiffness. Several seismic analyses have been applied during the designing process in order to determine the dynamical behaviour and the internal forces produced by the seismic actions, specifically the lineal modal response spectrum and the nonlinear static analysis (pushover). Furthermore, the displacement-based design method N2, have been introduced to determine the inelastic demand of the dissipative elements under the specific seismic actions of the L’Aquila. For the case of the beam-to-column joints, prequalified earthquake haunched joints have been considered. These types of connections designed as full-strength, are an excellent solution for the MRF system, since they remain in the elastic range during the application of the seismic actions, allowing the dissipation of energy exclusively by the dissipative elements.