Shear failure on masonry cross vaults

Beside the favourable behaviour under vertical static loads and the positive response in terms of stability, it was detected that the in-plane horizontal shear distortion represents a damage mechanism that is recurrently observed during post-earthquake surveys.

The lower stiffness of the central nave’s colonnade compared to the external walls can lead to differential displacements along the longitudinal direction and, consequently, the development of a shear damage mechanism in the horizontal structural elements. 

This failure is mainly identified by typical diagonal crack occurrence.

This kind of mechanism is rather unexplored, but it is particularly common in single-nave churches or three nave churches characterized by a large difference in stiffness between the nave and the façade and/or transept and in palaces with laterally constrained porches or loggias.

It was, therefore, decided to investigate the recurrences of the shear failure during the strongest events, which mainly affected Italy in the last two decades. The configuration which is studied in this work is represented by a central bay located in the lateral nave of a three-nave church under simple shear.