Coura and Valeria Bridges on Minho Railway line - old structures,updated performance

摘要

The pleasant Minho railway single lane line section from Caminha to Valenca crosses the Minho river at Valenca, through a very interesting and beautiful steel bridge. At Caminha it crosses the river Coura, by an also attractive steel bridge. Both are more than a century old and were refurbished and upgraded in a recent past and had before severe speed restrictions and load limitations: A) Coura bridge: This 1879 iron bridge is a 3 span 164m lower deck continuous closed lattice girder, for a live load of only 4t/m without dynamic effects allowance. It was totally supported by a new continuous steel arch bridge, so both work together, combining in a very elegant construction. B) Valenca bridge: This double-deck 1886 bridge is a steel 5 span 333m continuous lattice girder. Pathologies like excessive bending on the columns top sections, changing inappropriate bearing and a lock-up system for the braking action resulted in a demanding but discrete reinforcement.