Pedestrian Bridge in Andoain

Winner of a design competition organised by the Municipality of Andoain in 2002, the pedestrian bridge over the Oria river was built in 2005 and connects the school and sports facilities on the right bank with the town centre. The best balance of aesthetics, cost and performance in service (vibrations) has been reached through the selection of a single span steel-frame of 68 m (223 ft) of span embedded into two piers of reinforced concrete at each end: one is hidden in the embankment of the right bank and the other is integrated into an existing wall which defines the bed of the river on the left bank.In this way, an integral bridge (without joints) is obtained, in which the deck is fixed elastically and which enables horizontal movements caused by thermal
variations.

The deck is 3.6m wide and it is shaped by a weathering steel box girder whose height varies between 0.5m (L/72) at the span midpoint and 1.7m (L/40) at the edge. The box is very slender and railings need to work together structurally.