Abstract

The application of reliable predictive methods for the seismic vulnerability assessment of historical buildings represents a challenging issue in the process of risk mitigation at regional/national scale, in order to undertake appropriate strategies aimed at achieving acceptable safety levels. For the application of such policies, the availability of adequate procedures for the correct evaluation of the seismic risk of specific assets, like churches, is a fundamental topic of investigation. In this paper, a simple procedure based on the linear and non-linear kinematic approach is applied to evaluate the seismic capacity of masonry churches, both in terms of spectral acceleration and spectral displacement. To check the reliability of such a procedure, the obtained results have been compared with the damage scenario observed on a population of churches analysed by the research group in the aftermath of the 2009 L’Aquila earthquake.

Abstract

The Gothic style spread, starting from the 12th century, from the Ile-de-France to England and other countries of the Mediterranean area, such as Spain and Italy, according to different configurations and construction techniques, influenced by economic, environmental and social factors. The so-called Catalan Gothic style is not exclusive to the architecture of the Principality of Catalonia but extends to the territories of the Crown of Aragon and Southern France. Its most important characteristics, based on the unitary conception of space and horizontality, had the religious architecture as their major reference. Among other structural elements, the large use of diaphragm arches, built transversally to the longitudinal direction of the nave, has been identified as peculiar both in ecclesiastic and civil Catalan Gothic architecture, although this technique is widely diffused also in the rest of the Mediterranean Europe. The present study focuses on the behaviour of this construction system under horizontal loads. After some brief notes on the history, origins and evolution of diaphragm arches, preliminary outcomes obtained by means of seismic analyses are provided in this paper. In particular, the possible collapse mechanisms of such remarkable curved structures have been firstly investigated by implementing FEM Models derived from real Catalan examples. Therefore, seismic analyses by means of analytical models have been carried out on the detected cases in order to demonstrate the capacity of this kind of structural skeleton, the importance of geometric ratios and the influence that specific typical elements may have in modifying the seismic behaviour of the analysed structures.

Abstract

The meaningful seismic events occurred in Italy in the last decades showed the high vulnerability of monumental buildings and in particular of churches. In order to preserve such a precious heritage, operations aimed at the seismic risk mitigation based on the definition of suitable vulnerability assessment procedure are necessary. The high hazard of the Italian Peninsula and the huge amount of ecclesiastic buildings located in the exposed territories, stress the need to face the problem with innovative large-scale approaches. In this study, an architectural-engineering integrated procedure for the seismic assessment of existing masonry churches at a regional scale is proposed. Based on accurate historical investigation of typical Abruzzi churches, a typological characterization has been established, aimed at recognizing the common geometrical and constructive features of two types of medieval churches widespread in this area. Then, a numerical analysis has been carried out. In particular, by assuming simplified modelling hypotheses, two FE models representative of significant real cases have been implemented in Abaqus. By the elastic analyses, the main collapse mechanisms and the corresponding activation seismic accelerations have been determined. The obtained outcomes show an acceptable correspondence with the actual seismic damage revealed on similar churches in the aftermath of last seismic events, corroborating the reliability of the adopted integrated approach.

Abstract

Several seismic events have demonstrated the vulnerability of masonry churches. The long seismic history of the Italian territory has provided materials to observe and to study the structural performance of churches. Since the 1976 Friuli earthquake many studies have contributed to the definition of specific damage and vulnerability assessment methods for churches, based on the identification of macro-elements and kinematic mechanisms. In this context, the paper presents the application of a vulnerability assessment methodology developed and currently applied in Italy to a case study representative of the néo-roman church typology in Montreal, Québec. The study is part of a collaborative project between Politecnico di Milano and École de Technologie Supérieure of Montreal. The relevance of such a study derives from the moderate seismicity of Montreal associated to a high density of churches. Starting from a previous inventory of 108 churches in Montreal Island, the Néo-roman church typology was selected to be investigated. Specificities of this typology are the position of the bell tower in the middle of the façade and the interaction between the timber structure and masonry walls. This combination between the façade and bell tower macro-elements requires to reconsider the mechanisms associated to these elements in the original reference method. A detailed survey of the roof and bell tower timber structures of a néo-roman church was done, and a three-dimensional numerical model was developed for a better understanding of this type of structure. Modal analysis of a global model was then carried out and the first results of the modal shapes discussed.

Abstract

The seismic protection of cultural heritage is an important topic that has been faced by several researchers in the last decades. Seismic events of the past have highlighted the need of achieving a proper knowledge of the vulnerability of cultural heritage, in particular of churches, in order to put in the field proper mitigation measures at the large scale. According to this premise, this paper deals with the damage scenario observed on eighty seven churches hit by the 2016 Central Italy earthquake. In a first stage, the most important structural features of the studied churches are discussed and threated by the statistical standpoint. The reported information have been collected through the A-DC form, adopted by the Civil Protection Department and by the Ministry of Heritage and Cultural Activity and Tourism (MiBACT), which was used in the framing of the damage reconnaissance activity carried out by the ReLUIS Italian consortium in the aftermath of the earthquake. Also, the form has been used in order assess the damage of each macro-element and, then, to assign a damage index to each church. The presented work is framed in a wider research activity that aims at providing a predictive methodology for the vulnerability assessment of churches at the regional scale. This methodology was already calibrated on the basis of the 2009 L’Aquila seismic event. The outcomes presented in this paper will serve to further prove the reliability of the proposed model.