U-Bahn Linie 17.1 - Paris Grand Paris Express

Short description

With a length of 27 km, line 17 extends over 13 municipalities in the departments of Seine-Saint-Denis, Val-d'Oise and Seine-et-Marne. It connects nine stations between Saint-Denis Pleyel and Le Mesnil-Amelot in less than twenty-five minutes and will facilitate the daily life of nearly 565,000 people.

The project

New strategic axis for the Grand Paris with many connections, it offers a new mode of efficient transport to thousands of employees in the major employment areas of the North of the metropolis. Line 17 reinforces the development of major economic hubs in Île-de-France (Pleyel sector, Villepinte Exhibition Center, Roissy-Charles-de-Gaulle and Bourget airports) and accompanies the vast urban project of the Triangle de Gonesse.

The subject of our contract concerns the section on this line, 6.5 km long between Saint-Denis Pleyel and Le Bourget-RER with a common part with the line 16.

The 6km tunnel is excavated with an EPB TBM 9.80m diameter, tunnel mainly made in the sands of Beauchamp.

2 stations will be realized on the route, a first at the airport of Le Bourget, a second at the urban development project of the Triangle de Gonesse.


The main challenge is a planning challenge. Lot 1 of line 17 is the last of the Grand Paris lots to be launched with a delivery requirement for the 2024 Olympic Games : delivering a part of this line.

Further information

Key Figures

  • Realization 2019 – 2023
  • Total lenght 6km
  • Excav. cross section 75 m²
  • Geology Limestones of Saint Ouen, sands of Beau-champ, marls and stones

Implenia on site

Implenia France, Implenia Suisse, Implenia GmbH

Scope of works
Technical studies and excavation of a part of Metro Line 17 in Paris

Performed services
Tunneling works, specials fondations, earth-works, civil engineering

Construction methods

  • Ligne 17-1
  • EPB TBM, L = 1x 6.00 km, Ø = 9,80 m, seg-mental lining (thickness  = 0,40m); 
  • 7 ventilation and emergency structures con-nected to the tunnel
  • 2 subwbay stations : Le Bourget et Triangle de Gonesse.
  • Tunnel in open trench method, lenght 600m    

Project Participants

Société du Grand Paris

Lombardi - CSD

Implenia France, Implenia Suisse, Implenia GmbH

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