CERDEÑA BRIDGE IN BARCELONA

The Cerdeña bridge connects two urban areas separated by a cut-and-cover railway tunnel. The basic idea behind the design was to simulate a crossroads with chamfered corners; a configuration which is typical for this neighbourhood. This configuration is obtained from the crossing of the tunnel and the prolongation of the Cerdeña street. An ellipse was chosen in stead of an octagonal square, and it  is hiding completely the tunnel passing below it.  From this ellipse, two identical  spans of 45.6 m compose the prolongation of the Cerdeña street without  altering the concourse at ground level.

The main structural feature of the solution is the composite cross-section which consists of a multiple-cell box girder with very inclined webs. These webs are extended horizontally into two large lateral cantilevers, so as to achieve a soffit which is entirely formed in weathering steel.