Llinars HSR Bridge over AP7 Highway

Project Description

Completed in 2005, this was the very first steel bridge to be built on the Spanish High-Speed Railway (HSR) network, belonging to the section between Barcelona and the French Border. The 574 m long bridge comprises two parts: a 307 m long steel–concrete structure crossing the busy highway AP-7 and a continuous prestressed concrete box girder viaduct over the Mogent River with a longest span of 48 m.

The steel bridge is a continuous structure with five spans measuring  45+71+75+71+45 m respectively. The location of the piers was controlled by the highly skewed angle of the highway crossing and by the launching process used to erect the bridge. The bridge is designed as 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. The composite deck rests on 1 m deep transverse steel plate I-beams positioned 3.55 m apart. These beams are connected to the bottom chord, which is a 1.6 m wide box section with depth varying between 3.5 and 6 m.

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 HSR bridges. The design of this bridge achieved a cost-effective and aesthetically pleasant solution through the optimal use of materials, including steel and slender decks. To avoid interfering with the operation of Barcelona´s critically important tollway AP-7, incremental launching construction was used for the steel bridge.

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.