ADG performed the structural design of this one kilometer tall, 6.8 million square foot (approximately 670,000 square meter) residential tower, which was proposed to be the tallest building in the world. This building was originally the centerpiece of the man-made Palm Jumeriah island, located offshore of the Jumeirah Beach coastline in Dubai, United Arab Emirates. It was planned to rise out of a lagoon within the central canal of The Palm Island. The tower was intended to be an international landmark and create a new identity for the city of Dubai.
The building will house 724 apartments, having floor areas ranging from 300 square meter (3,000 square foot) simplexes to 600 square meter (6,000 square foot) triplexes with individual swimming pools. In addition to the residential portion of the building, an observation deck is planned at one of the top floors.
The structural form of Al Burj evolved from the structure of the bamboo plant. The tower’s footprint is composed of three triangular shapes with curvilinear sides and a hollow circular interior. The stiff exterior shell with the hollow core results in an extremely efficient structural system. The sides of the triangular shell are opened up to create three sub-towers. To achieve cohesive structural behavior between these sub-towers, they are tied together intermittently at six points using “sky bridges”, or solid floor areas inside the core. These sky bridges also provide two alternate means of egress for the occupants in the event of an emergency situation.
The efficiency of the structural system is highlighted by the fact that the structural elements fit around the architectural planning with minimal loss of valuable real estate in the structure. No interior columns are needed within any of the apartments. Two layers of reinforced concrete wall (exterior and atrium) form the vertical load-carrying elements, with apartments laid out between these two layers. These exterior walls are ‘punched’ with architecturally desirable large windows. The walls form a double-layered tube that acts as an efficient structural form to resist wind and earthquake loads. Following the natural increase in loads from top to bottom, the wall thickness and material strength is gradually increased to correspond to the load variation. Large openings in the three exterior faces of the building help reduce the wind pressures and significantly alleviate the detrimental effects of vortex shedding. Finally, the sky bridges provide rigidity needed to enable the structure to behave as monolithic entity.