The purpose of works is the execution of a part of the special foundations of the South-East section of the new Line 15 of the Paris metro. This section extends over 21 km, crossing urban areas and includes three crossings under the Marne and the Seine rivers.
The special foundations works essentially consisted in:
– deep diaphragms down to 65 m, with different thicknesses (800, 1.200 and 1.500 mm) and installation of a water-stop joint;
– injections at the TBM launch/exit shafts, injections for the construction of the tunnels connecting the shafts and the main tunnel and preventive injections for the excavation of diaphragms;
– bi-fluid jet-grouting at TBM launch/exit shafts