The PB6 tower is located at La Défense in Paris, between the Atlantic Tower and the Quatre Temps shopping mall. With 41 floors, each 3.45m high, it reaches a total height of 148 metres above the main pedestrian level of La Défense.
The Project Owner is PB6 Development, which is controlled by the American group HINES, one of the biggest private-sector property developers in the world.
The vertical mass of the tower has an almond-shaped section. That mass is cut through on the north facade by a vertical slit which narrows down to a level matching the vault of the “Grande Arche”.
The bearing structural frame of the tower is executed in high-performance reinforced concrete. The horizontal stress is taken up partially by the central core, measuring 31m by 14.1m, and by 16 columns along the facade and 2 interior columns, all in high-performance concrete.
The most heavily loaded columns accommodate compression forces of approximately 4,500 tons.
A complete finite-element model of the tower has been undertaken in order to analyse its static and dynamic behaviours.
- Main contractor for the execution of the tower’s structure
- Preliminary design for structure
- Production of the structure’s specifications as part of the contractors’ tendering documentation
- Construction works’ supervision and verification of execution drawings
The significant slenderness of this tower, with a core width of 14.1m for a total height of 180m, required very detailed wind studies combining wind-tunnel tests at CSTB in Nantes, statistical processing of data from the French Meteorological Office and probabilistic calculations considering wind speed and incidence.
One of the main dimensioning criteria was the requirement to remain within the acceleration limiting value of 1.8% of g in the head of the tower at ten-year wind values.
The use of high-performance concrete, specifically B80 for the columns and B60 for the tower’s core, make it possible to optimise the structure in order to meet architectural design constraints.
Client : PB6 Développement
Design joint-venture :
- Architects : Peï-Cobb-Freed & Partners, Saubot Rouit Associés
- Structure : setec tpi
Main contractor : Bateg
Period : 1998 – 2001