MECHANICAL INTERPRETATION OF PASSIVE HINGE FORMATION AND THE TRANSITION TO COLLAPSE MECHANISM IN HISTORIC MASONRY ARCHES

Abstract

Historic masonry arches maintain their stability through the redistribution of internal forces and changes in the contact conditions between adjacent masonry units. This paper presents a mechanical interpretation of passive hinge formation and the transition to a collapse mechanism. It is shown that the presence of multiple visible cracks is not, by itself, sufficient evidence of structural instability, as the mechanical role of the hinge zones is the governing factor. The proposed approach is validated through the analysis of real historic masonry arches, and a practical algorithm for structural assessment during condition surveys is developed.