Structural Assessment of Santa Maria Maddalena Church in Ischia Island (Italy) by Experimental Modal Analysis Under Operational Conditions

Abstract

During the seismic event of 21 st August 2017 in Ischia, many masonry churches were damaged. Within the inspected damaged churches, a very interesting case study is represented by Santa Maria Maddalena church, located on the hill of Casamicciola Terme, near to the epicentre. The church of Santa Maria Maddalena can be considered a 'unicum', since it was built in 1896, after the catastrophic earthquake of 1883, with a 'mixed' structure made mainly of yellow tuff blocks walls strengthened by iron profiles or wooden elements. Several examples of structures made of masonry walls with wooden elements embedded in the wall thickness, i.e. the so called 'baraccato system' are present in the island, while the use of iron profiles is rare. The paper is firstly aimed to present the results of detailed historical investigation, geometrical survey, damage status analysis and provisional safety assessment after the earthquake of 21 st August 2017. These activities were carried out in collaboration with the Campania Regional Directorate for Cultural Heritage (MiBACT). Within such a collaboration, an in situ dynamic test was also performed under operational conditions. The setup and the results of this test are here presented in order to point out the main features of the structural system in terms of relevant modal parameters, both at global and local level.

In-plane Behavior of Iron-Framed Masonry Panels: Numerical Analyses

“…If there is still a lack of knowledge on the behavior of the more traditional 'baraccato' system, there is a dramatic gap in the literature for the system made of iron elements, which represents a 'unicum'. A first step in this line is represented by the recent work of Casapulla et al (2019), mainly describing the damage status and the in situ dynamic test performed on the Santa Maria Maddalena Church in the Ischia Island after the seismic event of August 2017, and the Msc thesis of Di Napoli (2019) focused on its 3D modeling and safety assessment. The analysis of the damage in the church after the 2017 earthquake confirmed the effectiveness of such a construction technique since the church did not exhibit significant damage and out-of-plane mechanisms did not occur.…”

“…Since no experimental data on iron-framed masonry systems are present in the literature, the paper first took advantage of the preliminary study of unreinforced masonry panels experimentally tested by Anthoine et al (1995) in order to calibrate both the numerical models. Successively, the numerical analyses were carried out on the same panels reinforced by the external iron frames according to the same lay-out observed in the Church of Santa Maria Maddalena in the Ischia Island (Casapulla et al 2019). The numerical analyses are also aimed to furnish indications about the range of variability of the maximum loads and displacements expected in the steel strengthened panels, in order to design a reliable set-up for experimental tests.…”

The Timber-Framed (TF) Masonries in L’Aquila: The baraccato Aquilano

“…The reconstruction works following the successive earthquakes (Norcia in 1859, Casamicciola in 1883, Messina e Reggio Calabria in 1908, Avezzano in 1915) saw the use of T-F systems to attain resistance to lateral actions. In some cases, the baraccato referred to both timber or iron frames, consider the Santa Maria Maddalena church in Ischia with both Iron-Framed and Timber-Framed masonries [4]. However, the 17th-18th centuries plausibly represented the core of the baraccato evolution.…”