Failure mechanisms of arches and vaults of masonry existing churches in the romanian seismic area of Banat

Existing masonry churches are often defined by the presence of masonry vaulted and arched structures. Although resistant to vertical loads, they are particularly vulnerable structural elements under the seismic horizontal action. This paper aims at analyzing and classifying the main collapse mechanisms affecting existing masonry churches, mainly focusing on masonry arches and vaults, and making particular reference to the ones located in the Romanian region of Banat, an area particularly prone to shallow-focus seismic phenomena. The examined churches feature a single rectangular vaulted nave, a semicircular or polygonal apse separated from the nave by a masonry or wooden iconostasis, a short transept, and a centrally positioned bell tower on the main façade. They usually present brick masonry walls, brick masonry or wooden vaults, and high sloped wooden coverings. Photographic documentation obtained from past in situ surveys is reported to investigate the real behavior of these structures. Also, common restoration and consolidation interventions adopted in these churches for preventing collapse are listed and commented.