Real quality of life at Dippach

28 June 2023


Civil EngineeringPublic

Quality of life for Dippach

Last March, Félix Giorgetti began construction work on the Dippach-Gare bypass. Discussed for more than 15 years, this project for the Ponts et Chaussées and the CFL is as ambitious as it is long-awaited.

For many years now, the Route des Trois Cantons - the main thoroughfare for the municipality to the west of the capital - has been saturated. More than 8,000 vehicles pass through every day, slowed down by the PN5 level crossing, which is closed for up to 40 minutes an hour.

The new bypass will provide a direct link between the municipalities of Reckange-sur-Mess and Bettange-sur-Mess, offering an alternative to the Route des Trois Cantons, which runs through the conurbation, and eliminating its level crossing for greater safety.

With a length of 2.2 km, the route will comprise two lanes of traffic and two junctions at each end to ensure that traffic flows smoothly. It will comprise a number of structures and facilities:

  • a 125 m-long cut-and-cover tunnel, with two 50 m-long access hoppers, which will run under the roundabout towards Bettange-sur-Mess ;
  • an 85 m mixed metal and concrete footbridge for soft mobility;
  • a reinforced concrete overpass 15 m long and 5 m wide;
  • cycle paths;
  • a farm track;
  • Hydraulic structures such as canals and a retention basin;
  • a crossroads;
  • noise protection measures such as noise barriers.

Terracing in taupe

As the cut-and-cover tunnel is located on a water table, this is one of the main challenges of the project. That's why our teams have opted for a different methodology and will be carrying out mole excavation, as project manager Michaël Soro explains. "Initially, we will stabilise the area by drilling 400 90 cm diameter piles to a depth of 18 m. We will then pour the slab. We will then pour the cover slab to stabilise the piles. Then we'll dig underneath [the slab and between the piles] to make the invert and the walls."

Preserving nature

The environment also plays an important role in this new route. In order to protect the local fauna, our teams have installed protective netting and will build in crossings under the road to allow frogs, in particular, to cross in complete safety.

The Moulterbach stream will also be restored and enhanced, with a new bed meandering peacefully along the new road.

In keeping with the environmental approach, 85,000 m3 of material from the earthworks will be processed on site and reused for the pavement boxes.

In around two years' time, everyone will be able to travel in complete safety and enjoy this new environment to the full.