A twin diverging arches bridge in Milan Portello

摘要

The new De Gasperi Bridge, located at Milan Portello, is made of two steel arches, having a 80m span. The deck works as a tie, holding the arches thrust. The platform is a composite steel-concrete deck. In order to reduce the intensity of the tensile stresses in the concrete slab, the whole deck is prestressed by nine external tendons. A peculiarity of this bridge consists in the two arches diverging towards the lateral sides of the deck, with an inclination of 22,5 with respect to vertical planes. The deck longitudinal beams are supported by nine transverse box beams which, at their ends, are connected to nine couples of hangers, having tubular section. The hangers lie onto the same inclined planes of the arches and are normal to the arches axes. In order to avoid flexural stresses, the connection between hangers and arches was made by means of Cardan joints.