23/10/2023
Rehabilitation of the railway bridge on the Toulouse-Bayonne line
This historic railway bridge, located at Urcuit in the Pyrénées-Atlantiques region, enables the Toulouse-Bayonne line to cross the Ardanavy river. It is currently being restored.
This intervention is part of a global policy to restore old metal engineering structures, and is justified by the general condition of the structure.
Built around 1865, the current Pont-Rail consists of a steel deck with a lattice girder structure. As part of this project, the bridge will be replaced by a composite deck. The existing abutments will be upgraded and reinforced with micropiles and tie rods.
The geological context of the site poses significant challenges. The structure rests on an embankment varying in thickness from 0.5 to 3.7 m, on top of vasso clay alluvium found at depths of up to 25 m.
To ensure the structure’s stability, 30 m-deep micropiles will be installed to anchor them in the bedrock of sandstone marl and limestone.
Horizontal forces resulting from railway loads, as well as seismic forces, will be managed by 21 to 25 m-long passive tie rods installed at the head of the abutments.
