Borromini e le scale elicoidali. Ri-composizione di un paradigma geometrico-formale

The research proposes an analysis of the shape and geometry of the helical stairs, with reference to the Borrominian "lumacha" type of the San Carlo alle Quattro Fontane Complex in Rome, of particular interest not only for their geometric shape but also because trait d'union utility in function, balance and harmony. The spiral staircases, object in the course of the years of authoritative studies, deserve further study constituting architectural organisms characterized by peculiar spatial-perceptive relationships and revealing a geometric-modular design, coherent with the stereotomic principles of the treatises of time, verified through the survey and the experimentation of modern modeling techniques, useful to analyze the geometry, the proportional and constructive criteria used during the creative and realization process.