Experimental testing of the seismic in-plane displacement capacity of masonry cross vaults through a scale model

Since cross masonry vaults represent one of the more widespread types of hori-zontal structural elements in historical constructions, understanding their behaviour is acrucial precondition for the accurate assessment of the global response of buildings toearthquakes. In spite of the importance of this topic, the complexity of evaluation three-dimensional response of vaults still represents a challenge for researchers. Experimentalinvestigations can be a valid tool to analyse this difficult problem, as they provide usefulresults that can validate the reliability of the numerical and analytical tools developed foranalysis. In this paper, the results of an experimental campaign on 1:5 scale model of amasonry cross vault are presented. The main aim was to evaluate the response of the vaults inthe context of a global analysis of historic masonry buildings by determining their ultimate in-plane seismic capacity (diaphragm effect) in terms of stiffness, strength, and ultimate dis-placements. Their three-dimensional damage mechanisms on the vaults was also described.The model, made of3D printed plastic blockswith dry joints, was tested by statically applyingdifferent horizontal displacements settings to the abutments in order to simulate differentialdisplacements of the supports (walls or pillars). In particular, in-plane horizontal shear dis-tortions and longitudinal opening/closing of the abutments, as they are the most commonseismic damage mechanisms seen in masonry vault buildings, were applied.