ABSTRACT
The extension of the E line between the Haussmann-Saint-Lazare and Mantes-la-Jolie stations, one of the Paris regional express train network lines, includes the construction of a large underground railway station in the heart of the La Défense district. It is located directly beneath the iconic concrete shell structure of CNIT (Centre for New Industries and Technologies). Buildings of 5 to 10 floors are sheltered under the vault. The central volume of the station, with a capacity of 120 000 m3, must be excavated directly under these buildings. The construction sequence includes the load transfer (approximately 75,000 tonnes) on temporary foundations, the construction of columns supporting a thick transfer slab and the final transfer to this slab. So far, the first load transfer and separation of the existing shallow soles have been performed, as long as a first excavation step.
