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.
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.
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 8th 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.
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.