The seismic vulnerability assessment of Québec churches: considerations on territorial specificities

Masonry churches have demonstrated to be vulnerable to earthquakes. The cause of such vulnerability is due to their intrinsic structural characteristics. Many examples of Italian churches could be cited to illustrate this structural vulnerability, based on the long seismic history which characterizes this territory. A series of systematic studies have been performed since the 1976 Friuli earthquake, providing methods for vulnerability assessment, identification of macro-elements and the relative kinematic mechanisms, and damage classification. In this context, the present paper focuses on some territorial aspects, such as materials and techniques of construction, common in Québec churches. They should be considered in the evaluation of the structural performance of the church building under seismic actions. The long Italian history of seismicity and damage experience provides a knowledge base useful also in another context, such as the Canadian one. In this paper, some of the most important Italian earthquakes (Friuli, 1976, Emilia-Lombardy, 2012, Central Italy, 2016) are recalled for specific aspects that were observed and that constitute an experience in the field. These aspects are useful for a preventive analysis of some churches on the Island of Montreal, in the Province of Québec, Canada. Starting from a previous seismic vulnerability study, a research is in progress aiming to identify and define regional macro-elements or mechanisms specific to those churches. An adaptation of the Italian methodology for assessing the seismic vulnerability of churches to a different context, with proper materials and techniques of construction, is proposed in this paper. This approach leads to a method for the seismic vulnerability assessment for churches, specifically related to the territory, keeping as reference the already consolidated procedure.