RINTC-E: SEISMIC RISK OF PRE-CODE SINGLE-STORY NON-RESIDENTIAL STEEL BUILDINGS IN ITALY

The paper summarizes results from numerical investigations on seismic response of single-story non-residential steel buildings designed and built in Italy during the 1980s-1990s, i.e. prior to code enforcement of modern capacity design and ductility detailing rules. A typical geometry and structural layout were selected to generate an archetype building, considering trussed portal frames in the building transverse direction and concentric braces in the build-ing longitudinal direction. Following the simulated design, the case study building was modelled and analysed using OpenSEES. First, the paper describes the mathematical modelling of the mechanical response of critical building components as well as the global building model. The model represented explicitly the shear force-displacement response of bolted connections for truss members, as well as the axial-shear force-displacement response for column base connections. Low-cycle fatigue of buckling braces was considered following literature models to represent triggering of brace fracture. Two different envelope types were analysed and explicitly modelled. Following description of the finite element model, results from non-linear static analysis are summarized and critical building components are identi-fied. Subsequently, results from response history analysis with multiple sets of ground motions selected for increasing seismic intensity levels are also provided and commented on. Finally, conclusions from the presented numerical results are traced and future developments of the work are discussed.