The open-well staircase of Palazzo Di Majo in Naples between geometry and equilibrium | La escalera de ojo abierto del Palacio Di Majo en Nápoles entre geometría y equilibrio

The staircases represent one of the most impressive architectural expressions of the building. Many authors presented a great deal of research over the years on this matter intending to understand how they are designed and laid out. This paper is concerned with a particular structural type of masonry staircase, known as stair with open well or roman staircase. It aims to demonstrate that in masonry-vaulted staircases, the close relationship between the shape and static behavior is particularly evident, and geometry and construction are essential for their stability. The authors have proved this statement by studying Palazzo Di Majo’s open-well staircase in Naples, whose main structure consists of tuff vaults. The first part of the article is substantially descriptive and presents an in-depth description of the geometric and architectural features of the stair. The second part explains all the aspects concerning the equilibrium of this kind of stairways, within Heyman’s theory of masonry.