Rintc project: Nonlinear dynamic analyses of Italian code-conforming steel single-storey buildings for collapse risk assessment

Abstract

This paper reports on the results of an ongoing Research Project aimed at computing the risk of collapse in new buildings conforming to the Italian Seismic Design Code. Companion papers describe the overall Research Project, funded by the Italian Civil Protection Department (DPC), its different areas of application (reinforced concrete, masonry, steel buildings, etc.), the overall seismic risk calculation procedure and the ground motion selection process followed to identify the recorded ground motions used for the multi-stripe analyses for twenty different ground motion intensities. Specifically, steel structures are considered within this paper and the nonlinear modelling and analysis of steel single-storey buildings designed in cities with increasing seismic hazard are described. First, the paper presents the geometry, material characteristics and main design properties of the buildings, including their elastic dynamic properties. Second, the paper introduces the nonlinear models used for the nonlinear analyses: distributed plasticity models for beams, columns, and concentric braces including geometric imperfections for triggering of buckling. Pushover analyses are used for a preliminary evaluation of the nonlinear behaviour under increasing horizontal loads. Afterwards, the main results of the multi-stripe dynamic analyses are presented for different ground motion intensities.