Construction of a de-doubling viaduct at Pulvermuehle

The new viaduct measuring approximately 242 m will support two new railway tracks.

The project to construct a second railway viaduct next to the Pulvermuehle viaduct will consist of three distinct works, i.e.:

PART 1: CONSTRUCTION OF THE VIADUCT

The new viaduct measuring approximately 242 m will support two new railway tracks with a 4.60 m gap between them. The longitudinal axis of the construction will run parallel to the existing viaduct. The deck will consist of a mixed structure made up of a spatial triangular tube framework with reinforced concrete screed. Pathways on both sides of the future railway lines for use by railway personnel are planned and a noise barrier will be constructed at the outer side of the viaduct.

The deck will rest on abutted pillars at both ends and in the middle on four reinforced concrete pillars, varying between 12 and 24 m in height. The pillars will be hollow in the centre so as to allow easy access to the base and masts of the viaduct.

All abutted and middle pillars will rest on reinforced concrete rods.

PART 2: CONSTRUCTION OF A RIPRAP

The construction of a 275m-long riprap will allow the two new tracks on the new viaduct to be made longer and permit them to re-join the route of the existing tracks on the line Luxembourg-Wasserbillig at kilometre point 1.400. The gap between the two tracks on the viaduct will measure 4.60 m. As it is not possible to make the riprap larger by sloping it, it is necessary to build a riprap ridge consisting of a closed reinforced concrete trapezoidal box. The outer face of the frame will be diagonal and cantilevered, supporting in part a railway track and a pathway for railway personnel.

The construction axis will extend from the scheduled viaduct and will run tangentially to the track of the existing line.

Because the lift on the body of the riprap embankment is weak, it will be preliminarily strengthened by horizontal compaction. All of this will rest on two deep beds filled with reinforced concrete (up to 35 m in length), anchored in the sediment. A noise barrier will be constructed at the outer side of the construction.

To facilitate the construction of the concrete framework and to guarantee horizontal stability, a permanent vertical shield will be put in place behind the construction. The shield will be anchored horizontally and will be of a permanent nature, as it will serve to manage the ground’s horizontal forces pressing on the construction.

PART 3: ROAD TO THE RIGHT OF THE BOULEVARD D’AVRANCHES

The existing road, situated at the north exit of Luxembourg Station, to the right of the Boulevard d’Avranches and further up the road from the viaduct presently crosses only two railway tracks. In the projection, the new construction of approximately 100 m long, supporting the lanes of the Boulevard d’Avranches, will cross four railway tracks. The future third track is an extension of a side track, situated in the Rocade de Bonnevoie tunnel.

The existing bridge must be completely demolished and replaced with a new reinforced concrete construction. The inner mould of the structure will vary. The clearance will vary between 6.50 and 9.24 m. The width will vary between 23 and 29 m. Cable gutters are also planned all along the construction at the foot of the newly cast concrete anti-derailing structures.

The new structures will be cast on the long foundations and partially constructed with double wall elements, reinforced at regular intervals so as to be able to deal with the forces from the bearing beams of the concrete covering.

These beams will consist of partially concrete-wrapped metal HEB profiles. The concrete double walls put between the beams will serve as a permanent casing for the structure.

The north tympanum of the new structure was worked on from an architectural point of view and will be clad in a natural Ernzen stone front. The joints will be cut and the front cleft. The supporting walls will make the structure longer and will form the connection with the new viaduct.

The new construction will be equipped with permanent and emergency lighting, safety and viewing recesses and tunnels for railway signalling cables.

Brochure Expo Pulvermühle

Take a look on our brochure "Expo Pulvermühle" about the construction of the viaduct at Pulvermühle. Do not hesitate to contact us for a tour.

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