Viaducto "Arroyo las Piedras". Primer viaducto mixto de las Líneas de Alta Velocidad Españolas

?Arroyo las Piedras? viaduct The first Composite Steel-Concrete High Speed Railway Bridge in Spain

The paper describes an innovative solution in composite steel-concrete bridges for high speed railway lines. Designed by IDEAM, the ?Arroyo las Piedras? Viaduct is the first composite steel-concrete high speed railway bridge in Spain. This solution brings the strict box girder methods developed in Spain for road bridges over the last few years to railway lines. The new design focuses on typical twin plate girder solutions, frequently used in Europe, but modified to improve them with strict box girder capabilities, whilst keeping their construction advantages. Likewise, the double composite action frequently used in hogging areas is made general along the whole length of the bridge to provide it with the torsional stiffness required for adequately controlling the dynamic response when railway stock eccentrically runs along a single track. The paper also describes additional aspects of interest, such as specific details to improve web resistance to concentrated reactions whilst the deck is being pushed, some anti-seismic design linked aspects and the monitoring of pier deformability during the viaduct?s launching process.