An Abu Dhabi developer is putting an eye-catching spin on its 160-meter-tall flagship building by giving it a startling 18° list with a slight twist. Swathed in a structural-steel diagrid, Capital Gate’s wavy profile, currently two-thirds up, makes the Tower of Pisa, tilting only 5° from its vertical axis, seem positively upright. Getting the newer leaning tower to take on its deceptively leisurely lean is creating geometrical puzzles for its contractors. “Every steel member is different,” says Werner Matyas, senior project manager with the owner’s management firm, Mace Group Ltd., London. Around 7,000 tonnes of structural steel is going into the building’s primary diagrid and a smaller one around an atrium.
Because of the lazy-S profile and elliptical floor plates, each of over 12,000 glass panes forming the prefabricated diamond-shaped cladding units is a different size. The need to precamber and post-tension the core is novel even for the job’s seasoned managers.