Fragility curves for Italian URM buildings based on a hybrid method

Abstract

A hybrid seismic fragility model for territorial-scale seismic vulnerability assessment of masonry buildings is developed and presented in this paper. The method combines expert-judgment and mechanical approaches to derive typological fragility curves for Italian residential masonry building stock. The first classifies Italian masonry buildings in five different typological classes as function of age of construction, structural typology, and seismic behaviour and damaging of buildings observed following the most severe earthquakes occurred in Italy. The second, based on numerical analyses results conducted on building prototypes, provides all the parameters necessary for developing fragility functions. Peak-Ground Acceleration (PGA) at Ultimate Limit State attainable by each building’s class has been chosen as an Intensity Measure to represent fragility curves: three types of curve have been developed, each referred to mean, maximum and minimum value of PGAs defined for each building class. To represent the expected damage scenario for increasing earthquake intensities, a correlation between PGAs and Mercalli-Cancani-Sieber macroseismic intensity scale has been used and the corresponding fragility curves developed. Results show that the proposed building’s classes are representative of the Italian masonry building stock and that fragility curves are effective for predicting both seismic vulnerability and expected damage scenarios for seismic-prone areas. Finally, the fragility curves have been compared with empirical curves obtained through a macroseismic approach on Italian masonry buildings available in literature, underlining the differences between the methods.

A Novel Seismic Vulnerability Assessment for the Urban Roadway by Using Interval Valued Fermatean Fuzzy Analytical Hierarchy Process

“…A number of studies focuses on assessing the seismic vulnerability of buildings in order to predict their potential collapse during an earthquake (Boukri et al, 2017). Techniques such as fragility curves, vulnerability functions and seismic performance indicators are developed to assess the structural integrity of different building types under seismic loading (Boukri et al, 2017;Karimzadeh et al, 2021;Maruyama et al, 2010;Pitilakis et al, 2014;Sandoli et al, 2021;Vamvatsikos & Kazantzi, 2014). These assessments provide valuable insight into the susceptibility of buildings to collapse, which is essential for understanding the potential risks to road infrastructure (D. Wang et al, 2021).…”

A machine learning-based analysis for predicting fragility curve parameters of buildings

“…Various definitions have been provided for clarifying the concept of fragility curves by researchers [8][9][10][11][12][13]. Simply stated, fragility is described as the probability of reaching or exceeding a specified damage measure (DM) under a given earthquake Intensity Measure (IM) for a structure [3,8,14]. In the viewpoint of mathematic, fragility curves could be expressed as Eq.…”

“…As could be figured out from the above-mentioned explanations, the chosen IM could affect fragility curve of a building significantly. A macroseismic IM does not lead to accurate fragility curves because (i) it can cause interdependency between the vulnerability and the IM itself because it is obtained from observation of earthquake consequences on buildings, and (ii) it is a subjective parameter which means that it is influenced by the sensitivity and judgment of the surveyor [12,14]. Hence, parameters namely peak ground acceleration (PGA), peak ground velocity (PGV) and peak ground displacement (PGD) have been applied instead of macro seismic IMs [12].…”

“…It should be also stated that different parameters could be used as EDP such as interstory drift ratio (IDR), ultimate rotation, etc. The most usual EDP, however, is IDR since it could reflect the structures' damage state perfectly [14].…”

Multi-attribute-based procedure for seismic risk scenario in a historical area

“…Analytical or mechanical approaches with varying levels of detail are frequently used to assess the vulnerability of single existing buildings before undertaking structural rehabilitation interventions (Puncello and Caprili, 2023). The hybrid methods, for instance (Barbat et al, 1996;Kappos et al, 2006;Sandoli et al, 2021), combine the results of simulated damage statistics from an analytical model, for certain building typology, with post-earthquake damage data, and try to overcome the limitations of empirical and mechanical approaches, i.e. lack of appropriate data and computing effort, respectively (Calvi et al, 2006;Puncello and Caprili, 2023).…”