Fragility Curves of Existing RC Buildings Accounting for Bidirectional Ground Motion

Abstract

In recent decades, the considerable number of worldwide earthquakes caused considerable damage and several building collapses, underlining the high vulnerability of the existing buildings designed without seismic provisions. In this regard, this work analyses the seismic performance of a reinforced concrete building designed without any seismic criteria, characterized by a seismically-stronger and a seismically-weaker direction, such as several existing reinforced concrete-framed structures designed for vertical load only. The case study building was modelled in OpenSees considering a non-linear three-dimensional model, also accounting for the contribution of joint panel deformability on the global behavior. Thirty bidirectional ground motions have been applied to the structure with the highest component alternatively directed along the two principal building directions. Time-history analyses have been performed for eight increasing hazard levels with the aim of evaluating the influence of bidirectional ground motion on structural response and estimating the seismic vulnerability of the building. The seismic performance of the structures are provided in terms of fragility curves for the two principal directions of the building and for different damage states defined according to the European Macroseismic Scale.

CARTIS: a method for the typological-structural characterization of Italian ordinary buildings in urban areas

“…The CARTIS form contains the main parameters used in seismic vulnerability (Zuccaro and Cacace, 2015;Chieffo and Formisano, 2019;Polese et al, 2019;Chieffo and Formisano, 2020;Vettore et al, 2020;Brando et al, 2021;Faggiano et al, 2021;Menichini et al, 2022;Zucconi et al, 2022;Perelli et al, 2023). It collects the same information included in international inventory databases, such as the one used in GEM (Crowley et al, 2013), like vertical structures typology, number of storeys, height, slope of ground, year of retrofit, use, position in the aggregate, regularity in plan and in elevation, infill panels typology, horizontal structures, roofs.…”

“…As the numerous applications have shown (Zuccaro and Cacace, 2015;Chieffo and Formisano, 2019;Polese et al, 2019;Chieffo and Formisano, 2020;Vettore et al, 2020;Brando et al, 2021;Faggiano et al, 2021;Menichini et al, 2022;Zucconi et al, 2022;Perelli et al, 2023) the CARTIS Frontiers in Built Environment frontiersin.org methodology improves knowledge of the Italian ordinary building heritage, through the identification of further features, which affect vulnerability at territorial level (at municipal and regional level) with the aim of creating a common dataset. It can be used to define a taxonomy of building typologies representative of geographical areas and to develop vulnerability models and risk/impact assessment at local levels, with reference to minimum units of analysis such as the 'sector' or its submultiples, such as districts or cells (for example, square cells 250 m × 250 m).…”

“…The paper aims to describe the methodology of data collection and to show the first statistics of exposure distribution at national scale (by region and geographical area) on the basis of the information detected by 2022, in order to integrate the exposure data provided by ISTAT, currently used for the evaluation of the National Risk Assessment. The description of the CARTIS methodology also aims to better define the common approach of investigation of Italian ordinary buildings adopted by different research units for vulnerability assessments at local scale (Zuccaro and Cacace, 2015;Chieffo and Formisano, 2019;Polese et al, 2019;Chieffo and Formisano, 2020;Vettore et al, 2020;Brando et al, 2021;Faggiano et al, 2021;Menichini et al, 2022;Zucconi et al, 2022;Perelli et al, 2023). In the following sections, the main characteristics of the CARTIS form (CARTIS form, 2017) and related compilation manual (CARTIS Manual, 2021), being the main operative tools of the CARTIS method, are presented.…”