Masonry Vaulted Staircases: Interpretation of Equilibrium Paths

The subject of the stairs organized according to a typology improperly referred to as "cantilever stairs" requires a remarkable insight, in that its equilibrium is based on a complex interaction of forces. This is displayed in a three-dimensional context and can be recognized only after some highly refined numerical analyses. In the present paper a simplified interpretation of the equilibrium mechanism of such stairs is investigated, derived from a qualitative elaboration of some numerical result available in the literature, suggesting a path for approximate structural control based on a suitable one-dimensional model of the flight of stairs.