Cavalcaferrovia a Rho(Milano)

摘要

The paper deals with the design of a bridge over a railway in Rho (MI) currently under construction. The bridge is part of a new road inside the town, consisting of two approach bridges and one main span over the railway. The paper mainly regards the structural solutions of the central girder: two steel box arches crossed on key and a steel and concrete truss beam deck suspended from four stayed-cables to the arch key. The arch is shown from a distance, and serves the purpose of reuniting the community that had been divided in two for some time by the railway line. The structural solutions minimises the deck thickness (1.15 m on a span of 55 m) and ensures the minimum gradient of the road surface. The original erection method is shown. With a view to reducing interference to rail traffic to the minimum, the whole arch bridge was assembled to the side of the railway line (55 m length, 17 m width, 25 in height) in about two weeks, and then positioned on the piers in a single operation [2401 (weight) x 25 m (radius)] lasting around one hour.