On 6 March, the official symbolic launch took place for the works aiming at replacing all seven railway level crossings in Bilzen, in the Flemish province of Limburg. In December 2023, BESIX and BESIX Infra were awarded the Design & Build contract for this major infrastructure project by TUC RAIL. In its design, BESIX includes several state-of-the-art features to limit disruption to railway traffic.
Replacement of seven level crossings by two bridges, four tunnels, and two stretches of bicycle highway
The scope of the contract signed by BESIX and BESIX Infra with TUC RAIL includes the replacement of seven level crossings with two bridges, four tunnels, and two stretches of bicycle highway. The works will be phased out and take about three years until the beginning of 2027. The contract value for this project is around 31 million euros.
State-of-the-art design features
In the design phase of the project, the BESIX Engineering department is integrating several special features, such as the use of prefabricated concrete elements which will be put in place on-site, limiting traffic disturbance.
The four tunnels will be built using two different methods. Three tunnels will be composed of a prefabricated 450-tonne tunnel tube which will be slid under the tracks.
The fourth tunnel will be built according to the Stross method, which is often used for building underground structures, such as tunnels. It is mainly opted for when disturbance at ground level must be limited. In the Stross method, the walls are realised first, after which the roof is built and finished on top of these walls, at ground level. The ground level is then again available for other functions such as traffic or transport. Finally, the ground is excavated under the roof, as far as the deformations in the side walls allow. Where necessary, an intermediate floor or temporary horizontal propping is applied to accommodate these deformations. The excavation can then continue, and the underground structure is completed. A deep open construction pit is avoided, minimising disruptions to surrounding activities!
Special in this construction is the installation of the roof of the tunnel. The roof will be prefabricated alongside the tunnel. During one weekend - when the tracks will not be in service - the walls and a temporary intermediate support in the tunnel will be placed and the roof will be slid onto the walls. At the end of the weekend, the tracks and cables will be re-installed.
The two bridges will also be built according to two specific methods. For one bridge, BESIX will build the deck first and will then slide it over the catenary. For the other bridge, pillars will be placed along the tracks, after which prefabricated concrete beams will be put on top of them.
Additionally, BESIX will apply very specific foundation techniques, such as sheet piling, soilmix walls, micropiles, grout anchors, screw piles, or concrete prefabricated piles.
Altogether works conducted by BESIX on-site also include dismantling the catenaries and rails, waterproofing, backfilling, and load-bearing tests. BESIX is also in charge of the actual reinstallation of the railway infrastructure, including ballast, levelling, track laying, and the various works involved, such as welding. BESIX Infra will be responsible for sewerage, excavation works, and road construction.
Erik Rombouts, BESIX Project Director: ‘We are extremely proud that BESIX was awarded this contract by TUC RAIL, which features a variety of infrastructure elements for which BESIX and BESIX Infra can apply their internal engineering and construction capabilities to their fullest to increase public safety’.
Largest level crossing project in Belgium for better safety and mobility
This endeavour in Bilzen constitutes the largest current level crossing project in Belgium and is a joint project of TUC RAIL, Infrabel, De Lijn, the Flemish Region, the city of Bilzen, and Aquafin. The replacement of the level crossings aims at further increasing safety on the Belgian rail network and for road users. It will also benefit train punctuality and mobility in Bilzen and Limburg.
Jan Hannes, General Manager BESIX Infra: ‘This project is a nice continuum of the project we finalised in Diepenbeek in 2022, where we also replaced seven level crossings with several infrastructure elements. We thank the client for putting their trust in BESIX and BESIX Infra again for this new major infrastructure project.’
BESIX's experience in similar projects, together with the group's engineering skills and execution excellence, is a definite asset for the successful completion of this complex and diverse infrastructure project. The project will be divided into several phases to allow the public transport lines to always remain in service. BESIX is currently executing the design phase and works are planned to start in the Summer, to be completed by the beginning of 2027.