On the theory of the ellipse of elasticity as a natural discretisation method in the design of Paderno d’Adda Bridge (Italy)

The Paderno d’Adda Bridge, Lombardia, northern Italy, is one of the very first great iron constructions designed through the practical application of the theory of the ellipse of elasticity, a graphical-analytical method of structural analysis that was developed in the 19th century. It embeds a natural discretisation of the structure into a series of elastic elements, treated then with standard tools of geometry of masses. In this work, the application of such theory to the calculation of the parabolic arch of the bridge is inquired, attempting to breathe, at the same time, the beauty of the architectonic and structural conception directly linked to that; later, results are compared with much modern approaches that also consider now-available numerical discretisation methods.A further, definite aim of this work is also that of trying to promote interest on the bridge, on its actual state of conservation and future destinations. Not only it represents a true industrial monument and a living testimony of the scientific and technological developments of the time but also a beautiful, effective achievement of architecture and engineering through the methods of Strength of Materials.