Assigning the macroseismic vulnerability classes to strengthened ordinary masonry buildings: An update from extensive data of the 2016 Central Italy earthquake. (August 2021)

• Record Type: Journal Article
• Authors: Saretta, Ylenia; Sbrogiò, Luca; Valluzzi, Maria Rosa
• Is Part Of: International journal of disaster risk reduction. Volume 62(2021)
• Publication Date: 2021-08
• Subjects: 2016 Central Italy earthquake -- Masonry buildings -- Strengthening interventions -- EMS-98 -- Vulnerability classification; Emergency management -- Periodicals; Risk management -- Periodicals; Disaster relief -- Periodicals; Hazard mitigation -- Periodicals; 363.34
• DOI: 10.1016/j.ijdrr.2021.102318
• Languages: English
• ISSNs: 2212-4209

Abstract

Abstract: Damage scenarios caused by the 2016 Central Italy earthquake confirmed the relevant role of interventions on masonry buildings' seismic performance, also by increasing (rather than reducing) their vulnerability. Notwithstanding, current literature procedures aimed at assigning to buildings an European Macroseismic Scale 1998 (EMS-98) vulnerability class (A to F) do not consider such influence especially referring to the several intervention techniques applied to masonry buildings since the 1980s in Italy. This impaired a proper matching of vulnerability classes to the real performances, as strengthened buildings are conventionally assigned to average vulnerability conditions (class C). In the present work, vulnerability classes are appropriately assigned to buildings in strengthened conditions, basing on the analysis of 2264 dwellings placed in 19 settlements. Inspections were carried out with a purposely developed rapid visual screening procedure. A performance-based definition of structural types considered a building's masonry quality, diaphragms' stiffness, and kind of interventions graded between downgrading and upgrading. Types with the same behaviour were grouped into vulnerability classes, in the full range from A to D, through a literature model compatible with the EMS-98. Rubble stone buildings with downgrading or worsening interventions behaved like those in original conditions (class A), whereas improved buildings typically performed like class C. Upgrading interventions led to class D, similarly to modern clay block buildings. Masonry quality influenced the classification more than diaphragms' stiffness. The empirical membership of each type to vulnerability classes was obtained, that which allowed to include variously strengthened masonry buildings within the EMS-98 framework. Highlights: Discussion of literature procedures to assign a building's EMS-98 vulnerability class. Dataset of 2264 masonry buildings within 19 villages in the area struck by the 2016 Central Italy earthquake. Definition of structural types including interventions on buildings commonly applied in the last 40 years in Italy. Performance-based assigning of vulnerability classes from A to D to strengthened buildings.