Project Description

Completed in 2007, this bridge was the first steel structure to be built on the High-Speed Railway joining the cities of Madrid and Barcelona. It is located just north of the Barcelona International Airport, before the railway goes underground and draws a sharp turn before heading for the city.  The 870 m long bridge comprises two parts: a 340 m long steel–concrete structure which spans a five-lane highway and a railway; and a continuous prestressed concrete box girder viaduct across the Llobregat River with a longest span of 50 m.

 The steel bridge is a continuous structure with six spans measuring  44+63+63+63+63+44 m respectively. The bridge consists of a king post truss with curved diagonals, which supports a composite steel-concrete deck. The 14 m wide deck accommodates two ballasted tracks, for a total bridge width of 17 m. Transverse I-beams of 1 m depth spaced every 3 m provide the base upon which the composite deck rests. The bottom chords, the king posts and diagonals are made up of steel box girders.

 Design/Construction Approach

Design was carried out meeting the Eurocode requirements, including strict provisions related to the dynamic behavior and rail-structure interaction given the complexity of High-Speed Rail bridge structures. To achieve cost-effective solutions, the bridge design relied on the optimal use of materials and the careful design of structural systems. To avoid interfering with the traffic underneath, incremental launching construction was used for the steel bridge. The concrete viaduct, for its part, was cast in place using the movable scaffolding system.

Further Information

J.A. Sobrino – Moving at the speed of steel. Civil Engineering Magazine, Volume 78, Number 4 pp. 69-75. ASCE, April 2008.
J.A. Sobrino – Two steel bridges for the high speed railway line in Spain. WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Stahlbau, vol 79, issue 3, pp. 181-187, March 2010.

Barcelona (Spain)
Key Elements
High-Speed Railway Bridge, Incremental Launching Method, Movable Scaffolding System
Feasibility Studies/Conceptual Design
Detailed Design
Assistance During Construction
Erection and Construction Engineering
Sant Boi HSR Bridge over the  Llobregat River
Sant Boi HSR Bridge over the  Llobregat River
Sant Boi HSR Bridge over the  Llobregat River
Sant Boi HSR Bridge over the  Llobregat River