Resisting system and failure modes of masonry domes

The research synthesized in this paper focused on ultimate strength, structural safety assessment, and collapse of masonry domes. Activity was directed at analyzing the relationships between safety factor and geometry, and carrying out research targeted at reducing the incidence and severity of structural failures in cultural buildings. This paper shows that the resisting system of a masonry dome is not the two-dimensional shell, but a one-dimensional mechanism that derives from the splitting of the shell and drum. The resisting system, whose geometry depends on the dome shape and brick or stone pattern, may include the lantern and/or the masonry constructions around the drum. Well-known domes taken from architectural cultural heritage are used to exemplify the pivotal role of geometry and construction techniques in providing ultimate strength. These examples also show the importance of considering the architectural design of the time, in structural analyses. The results found in the paper suggest how to provide masonry domes with adequate safety, using the minimal level of structural intervention; in particular, without altering the way the building reacts to applied loads. Hence, the paper helps understand how to reduce the amount of structural work, which, in turn, guarantees conservation and restoration, as well as safeguarding. The conclusions are devoted to analyzing which observations are valid for seismic assessment and how the other observations have to be modified for seismic actions. (C) 2014 Elsevier Ltd. All rights reserved.