Project Champigny-sur-Marne, France

Grand Paris Express - OA 813

new line 15 South

On the new line 15 South of the Grand Paris Express project, the special shaft OA 813 is the entry point for the first tunnel boring machine of the largest European urban project.

Technical specifications

Diaphragm wall

  • 21 panels
  • 1,20 m thick
  • up to 24 m deep
  • 4.000 m³ excavated work & 4.000 m³ concrete poured

Preparing the soil

In this project, we have used a special cutter to bore into the specifically fractured rock that composes the soil of Champigny-sur-Marne.

In order to avoid sludge losses while boring, our teams prepared the terrain by improving the soil with injections before the realization of the first panel of the diaphragm wall.

The 1st TBM of Grand Paris Express

This special shaft is the entry point for the first tunnel boring machine or TBM (drilling circular section tunnels in soils and rocks) to be used for the Grand Paris Express project.

In the tradition of Sainte-Barbe, protectress of minors and underground workers, each TBM is named after a godmother. The name of the first tunnel boring machine of the Grand Paris Express has been unveiled: "Steffie-Orbival". And we are very proud to say that Steffie Biou is our colleague from Atlas Fondations, operator-cutter for this project.

More information on the TBM's work can be found on the website of the Société du Grand Paris

More information on the baptism of "Steffie-Orbival" during KM3 event here.

The "Grand Paris Express" project

With the Grand Paris Express project, the French capital will receive a second metro network aimed at serving its suburbs. 
The scope of the work is impressive: four whole new lines, extensions of two existing lines, seven new technical centres and no less than 68 new stations, this ambitious project will double the size of the current Paris subway (from 220 km to 445 km), which serves principally the 20 districts located inside the Paris ring road (périphérique). 

The new lines of the Grand Paris Express will be connected to the existing transport network. Essentially underground, the new metro will cross the municipalities of the greater Paris metropolis to connect them among themselves and with the capital. This will make it easier to get from one part of the Île-de-France to another without going through Paris, but also to reach more quickly the heart of the capital from its suburbs.

The Grand Paris Express will serve the major business areas (airports, business centres, research and university centres) and other suburbs that are currently difficult to access. It will bring everyone closer to their workplace and make daily journeys faster and more pleasant. Finally, it represents a new alternative to the car, thereby reducing pollution, traffic jams and helping to create a metropolis that is more respectful of the environment.

It is the largest urban project in Europe nowadays.

Project details

Project name

Grand Paris Express - OA 813


Railways, Tunnels


Diaphragm wall

Contract type



Champigny-sur-Marne, France

External partner(s)

Groupement Alliance


SGP (Société Grand Paris)

Building Period

2017 - 2017

Reinforcement shaft

Diaphragm wall

Aerial view

Steffie, our colleague operator-cutter


1st Tunnel Boring Machine (TBM) of the project

KM3 event

Excavation work inside the wall

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