PSI - Issue 44

Valentina Buonocunto et al. / Procedia Structural Integrity 44 (2023) 67–74 Valentina Buonocunto et al. / Structural Integrity Procedia 00 (2022) 000–000

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1. Introduction

Several earthquakes occurred in Italy have produced major economic and human losses, in most cases because of the strong vulnerability of existing buildings. Unreinforced masonry (URM) buildings are a significant portion of the Italian built heritage, particularly within historic centres (e.g., Benedetti et al. 1988).

N omenclature d c

lateral displacement of control point Young’s modulus of masonry uniaxial compressive strength of masonry uniaxial tensile strength of masonry

E f m

f t

f v 0 G G ft

pure sliding shear strength at zero confining stress of masonry

shear modulus of masonry tensile fracture energy of masonry peak ground acceleration thickness of load-bearing wall

PGA

t

τ 0

shear diagonal shear strength at zero confining stress of masonry

V b

base shear of URM building

The methodologies currently in use for seismic vulnerability assessment of buildings make use of different approaches, as follows: empirical methods; analytical methods; hybrid methods; and expert judgement-based methods (e.g., D’Ayala 2013). Such procedures can be applied to building exposure databases that contain information – with different levels of detail – on construction characteristics that may affect the physical vulnerability of buildings. At national level, the building stock inventory essentially refers to the ISTAT census database, whose information on the characteristics of buildings is extremely scarce. Uncertainties on seismic vulnerability estimates are therefore very high, both because of poor available information and complexity of the problem. In this paper, a novel methodology is proposed for seismic vulnerability assessment at regional scale, overcoming the issues related to the consideration of general taxonomies for masonry types (like those provided by current codes and guidelines) and typological characteristics of URM buildings. To that aim, the CARTIS database (e.g., Zuccaro et al. 2015) was used for characterization of exposure to seismic hazard, retrieving region-specific data on existing URM buildings. Accordingly, Campania region (Southern Italy) was selected to collect data and identify building archetypes for seismic vulnerability assessment. A fully automatic procedure was developed and implemented in MATLAB (2020a) to randomly sample URM buildings, deriving their structural models based on the equivalent frame method, and assessing their seismic performance. The study then included the derivation of analytical fragility curves, followed by their conversion to the MARSmodel (e.g., Masi et al. 2021). Fragility curves were thus implemented into the IRMA portal for seismic risk assessment and damage assessment (e.g., Borzi et al. 2018 and Borzi et al. 2020), finally validating the fragility models against damage observed after the 1980 Irpinia earthquake (e.g., Braga et al. 1982, Gorretti and Di Pasquale 2002, Porfido et al. 2021 and Porfido et al. 2022) using the Da.D.O. platform (e.g., Dolce et

al. 2017 and Dolce et al. 2019). 2. Fragility analysis procedure 2.1. Region-specific exposure data on residential URM buildings

Based on the CARTIS database, which provides exposure data on buildings located over the whole Italian territory, the authors of this paper focused on residential URM buildings located in Campania region. CARTIS includes a huge number of electronic sheets, each of them divided into 4 sections, from 0 to 3. Section 0 includes the identification of the municipality under consideration and its decomposition into a number of urban compartments. Sections 1 identifies each of the prevailing typologies in a generic way and must be completed for typology of each subvision of the