The southern extension work of line 14 (lot GC03), which involves the construction of a 4-kilometer tunnel, as well as the construction of 3 stations entirely in diaphragm walls (Chevilly 3 Communes, MIN Porte de Thiais and Pont de Rungis) and 3 ancillary works, have been in progress since spring. Sefi-Intrafor, which is in charge of the construction of all the special foundations of the 3 stations and ancillary structures, began work in May 2018 with the Pont de Rungis station, for a period of 2 years.
The Sefi-Intrafor teams started the work in May and June with injections of gypsum dissolution filler on “Pont de Rungis”. The realization of the diaphragm walls of the future station began with the first concreting in July. The 10 1500mm thick panels and 37 1200mm thick and 34m deep panels were completed on October 1. In total, 12,600 m3 of excavated material, 12,000 m3 of poured concrete and 1,250 tonnes of steel were placed. Razel-Bec has started the earthworks, and the box will be used as a starting point for the tunnel boring machine which will be mounted from January 2019 for commissioning next April.
At the same time, filling work took place this summer at the “Chevilly 3 Communes” station. The diaphragm walls of this structure have been entirely subcontracted and begin on November 5th.
The Works teams are currently in the filling and preparation injection phase at the "M.I.N. Porte de Thiais ”, for the start of diaphragm wall drilling in early December2018.
Treatment injections are underway on the Petit Leroy annex structure.
All the Dwalls are made with a grab. Part of the “M.I.N. Porte de Thiais "will require the use of a underhead grab, in order to produce the diaphragm walls under a 125,000V high voltage lines.
Client : RATP
Site supervisor : ELIOS (gpmt SYSTRA – SETEC)