First steps towards the Cents gateway

The pedestrian bridge will provide a concrete solution to improve mobility in Luxembourg City. Citizens will be able to reach Cents from Rue Tawioun and Weimershof from Rue des Bleuets in just 200 meters. Neudorf will be connected to the bridge via an elevator with a capacity of 60 people, which is also perfectly suited for cyclists.

A dizzying crossing

The technical specifications are impressive: the footbridge consists of two main spans, 65 m on the Weimershof side and 135 m on the Cents side. The central pier, rising to a height of around 70 m, will support the structure, while the elevator tower in Neudorf will reach a height of around 60 m. The deck, 6 m wide with a usable width of 4.5 m, will be positioned at a height of approximately 50 m. The difference in height between Weimershof and Cents is approximately 5 m, adding an additional challenge to the assembly of this innovative footbridge.

A series of challenges 

The earthworks, which involved moving 3,000 m³ of earth, prepared the ground for the next stages. At the same time, we laid the deep foundations: piles and micropiles.  We are currently working on the abutments: the raft foundations, the walls, and the deep foundations for the pier. Once this phase is complete, the steel structure will be installed by Cimolai, our partner specializing in steel construction. 

The prefabricated elements, measuring around 20 meters and weighing approximately 50 tons each, will be assembled and welded on site to form the pier and elevator shaft.

At the same time, we will proceed with the cable pulling. The first operation consists of sending a light 6 mm nylon cable with a drone, which will serve as a guide for the gradual pulling of the final cables up to 152 mm in diameter using winches.

Finally, we will move on to the assembly of the voussoirs and the deck of the footbridge.

An innovative lifting system, using the structure's main cables, will enable the concrete elements to be positioned with precision and the deck to be suspended. The deck will be assembled from Weimershof to Cents, comprising a total of 40 elements. This innovative technique of assembling the rigid deck using flexible cables is being used for the first time in Luxembourg and represents a real challenge. It is essential that the structure remains perfectly linear, which requires careful monitoring and regular adjustments.

A major challenge

The site is located on the edge of a hill and has very little space, which is a real challenge.

On the Weimershof side, the earthworks proved to be particularly complex: as access for trucks and machinery is limited, multiple loading and reloading operations are necessary.

This limited space also influenced the choice of tower cranes for optimized footprint: a Liebherr 34k on the Weimershof side and a 42k on the Cents side.

IN FIGURES 

200 m

crossing

70 m

height of the central pier

6 m

width of the footbridge