Seismic assessment of masonry cross vaults through non-linear static analyses

Masonry cross vaults are common structural elements in historical buildings. They are largely diffused in all European countries, including those characterized by higher levels of seismicity. Although they have been constructed for centuries, they represent some of the most vulnerable elements of traditional architecture, especially with reference to horizontal loads. The understanding of their behaviour under seismic loading and the definition of their safety are crucial aspects for the accurate assessment of the global health conditions of historical buildings. In the present work, masonry cross vaults are analysed through the Finite Element Method (FEM) and static non-linear analyses are performed considering the effect of different brick pattern. A simplified micro-modelling approach is adopted for the generation of the FEM models and two different brick arrangements are considered, i.e., radial bricks and diagonal bricks, which are the most widespread in European cross vaults. Static non-linear analyses are performed by monotonically incrementing a lateral acceleration until collapse. Results are analysed in terms of maximum load factor, crack pattern and damage mechanisms. The analysis of the results shows that the masonry apparatus strongly influences the vault seismic response both in terms of stiffness and ductility as well as in terms of global capacity.