On this project our challenge was to build an 18,000-square-metre train station 20 metres underground that provides quick and easy interconnections in what is France’s busiest multimodal rail hub (including connections to other transport systems) as well as convenient access to the esplanade at La Défense. The project calls for the redevelopment of CNIT (the centre for new industries and technologies), including adding 7,000 square metres of retail space.
To meet a key project objective, our teams will have to deploy solutions that minimise noise pollution at the site and on the floors above the worksite. That is why an “acoustic sarcophagus” (including the floor, walls, and ceiling) encloses the worksite below CNIT.
The project comprises several operations: strengthening the foundations at CNIT, which will be placed “in suspension” while its 124 piles are reinforced; building the main structure of the train station; developing connections to public transport networks and CNIT; creating various exits for line E of the RER; ensuring access to users with reduced mobility (lifts, platforms, ramps, slip-resistant passageways, and tactile bands).
In late 2015, initial construction operations in the train station began with the re-routing of utility networks servicing CNIT. Later, an opening was created several levels below CNIT to facilitate project logistics. Subsequently, this space will accommodate escalators, staircases, and lifts, linking the station to CNIT. Later still, the foundations of the car park under CNIT will be reinforced, and a foundation slab under which the train station will be built will be implemented.
The last stage of the project consists in excavation and the creation of the various structures of the train station through works to be carried out during day and night shifts in 2018. Final development tasks will get under way in 2019.