— News — Eole shafts project for French rail company SNCF

Depending on the structures, Soletanche Bachy France intervenes before or after treatment of the future connections between the five shafts and the tunnel created under the GC-TUN package.

After completing the general installations on the first two shafts, the project is moving towards a year mainly focusing on foundations: the walls of four of the five shafts are due this year, with two or three other structures in parallel. The last shaft is due for completion in early 2020.

 

Hôtel de Ville shaft

This shaft, located in the municipality of Neuilly-sur- Seine, is on the side-road alongside Avenue Charles de Gaulle. The shaft’s cross-section is a rectangle of 15.5m by 6.6m, made of a diaphragm wall with a thickness of 1 metre, which is anchored in the plastic clay bedrock to a depth of 48m.

This shaft has one particularity compared to the others: four refends will ensure that the walls butt against the bottom of the excavation until the raft is poured. These refends are implemented in advance on the perimeter wall.

 

Schedule

• October to November 2018: general installation
• Mid-December 2018 to end February 2019: installation of the diaphragm wall slurry plant, pre-injection test area, purges, guide walls, and pre-characterisation excavation. At the top of the wall, metal profiles will be installed in the diaphragm wall to create a Berlin-type wall. This Berlin wall will allow the excavator to approach the shaft as close as possible. The excavation and civil engineering will be carried out by our partners in the consortium. On this shaft, SBF is building the walls before treatment of the connection.
• End-February to end-March 2019: creating the four refends
• End-March to early-June 2019: creation of six diaphragm wall panels
• Early June 2019: completion of shafts and pumping tests

 

Friedland shaft

This is the heart of the project between the GC-TUN and GC-PUI packages, on the critical pathway of the project. This shaft is located in Paris’s 8^th arrondissement, between Avenue de Friedland and its side-road. This is a rectangular box of 25m by 8.5m, in diaphragm wall with a thickness of 1 metre, which is anchored at a depth of 58m in fine, so-called Cuise sand.

 

Schedule

• November 2018 to March 2019: general installation of the shaft
• March to September 2019: treatment of the connection to GC-TUN
• From October 2019: start of work on diaphragm walls

 

Marché / Carnot / Messine shafts

These three shafts are circular with an internal diameter of 8.5m and a thickness of 0.8m. Each shaft is made up of eight individual panels.

The depth varies between 40 and 66m. The Carnot and Marché shafts will start at the end of September 2019 and will be completed by early December, then work will move onto the Messine shaft at the end of 2019.