La struttura lignea di copertura dello Scalone dell’Università di Pavia

In 1819-23 a comprehensive plan for the expansion and improvement of the palace of the University of Pavia was implemented by professor Giuseppe Marchesi. This plan required the design of a new monumental staircase, appropriate for the magnificence of the refurbished building. Since he designed the staircase in an existent part of the palace, Marchesi had to face many problems. He decided to cover the space with a large barrel vault adorned with lacunars, but to limit the expenses to the minimum he decided to maintain existing walls and roof. These restraints led him to interesting design choices; with regard to the roof, he kept existing trusses, but to gain height for the vault he modified them by cutting their timber tie-beams and substituting them with wrought iron tie-rods. The paper will describe the construction history of the grand staircase and building techniques used in the roof structure which show a very early application of iron tie-rods in timber trusses.