Technical overview
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 had 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 comprised several operations: strengthening the foundations at CNIT, which was placed “in suspension” while its 124 piles were 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. Subsequently, an opening was created several levels below CNIT to facilitate site logistics. Then, this space accommodated escalators, staircases, and lifts to link the station to CNIT. The works then included rebuilding the foundations of the car park under the CNIT, and creating a slab under which the station will be dug.
The final stage of the project involved the creation of the station structures, followed by excavation, with day and night work in 2018. The finishing works were carried out in 2019.
