In addition to the Grand Paris Express stations, Trevi also works on the TBM launch well

In addition to the stations, Trevi also works on the TBM launch well, the equipment that will excavate the underground lines; one of these is under construction in the town of Chelles, north-east of Paris, on a construction site on line 16 of the metro.

This well is particularly difficult since it has a very complex geological situation: the presence of chalks in the first 30 m complicates the realization of the foundation works, which consist mainly of circular diaphragms that are 1500 mm thick, at a depth of approximately 62 m.