The Building

On the building scale, the tower is a simple, elegant composition informed by its uses and the technology of our time. Once the building splits, the twin towers are trapezoidal in plan. The shortest faces of the two legs of the tower slope away from each other from 13 meters at the bottom to 20 meters at the top. Each trapezoidal tower has four super columns along the longest side and one along each angled side. These columns are aligned with the towers’ 17 x 17 meter core.

Each outrigger extends across the entire width of the linked structure, connecting the two central super columns along the longest side of the towers, as well as to the cores. Cross-trusses connect the super columns with the core at the same levels as the outrigger columns. As they rise, the super columns each taper. At the top, a hat truss is employed to connect the six super columns to the core at the roofline.

As with any building of this height, wind loads were a major consideration. Much focus was given to the wind aerodynamics created from the vortex shedding effect. The sharp corners of the building were important architecturally, so the engineers and the architectural design team worked closely in the creation of an aesthetically pleasing solution. A series of open “slots” are placed along the outer corners, beginning above the second bridge. The slots reduce the wind load and add to the architecture of the building.

The 151-story building sits within a 69 x 76.5 meter footprint atop a 5.5 meter thick reinforced concrete mat that is supported by 200 RCD (reverse circulating drilling) piles that are each 2.5 meters in diameter and reach a depth of more than 50 meters. The change from a composite system to an all concrete system was done so to reduce construction time.