Abstract:
The EOLE project includes the modernization or creation of 55 km of tracks (including the digging of 8 km in tunnels), the modernization or creation of 14 stations (including 3 entirely new stations) between Haussmann St-Lazare Station and Mantes-la-Jolie. Bouygues Travaux Publics was chosen has main contractor in the realization of the open air station at Porte Maillot – GPM (Gare Porte Maillot) to carry out all foundation works as Piles, Micropiles, Diaphragm Wall, Injections and Jet Grouting. The works of Jet Grouting consisted in the treatment of the sand layers (sables de cuisses) in anticipation of the future excavation underground works of the adjacent north and south station galleries and TBM (Tunnel Boring Machine) exit plug. The realization of these works required several analysis and adaptations regarding the grout plant and spoil pipeline installation plans. This analysis main points were the altitude difference and distance between the work platforms (located 20 m below the surface), and the spoil pits used for spoil evacuation causing a possible pipeline blockage. The geological profile of the reclamation area where the works were carried was composed by a layer of limestone and a thick layer of sand at the bottom. A layer of lignite was found on south galleries and plug gallery during drilling works raising the spoil evacuation difficulty. This paper describes the means put in place to manage the spoil in this highly constrained context. Keywords: jet grouting, lignite, spoil