A unique shape and an unusual mechanism to control wind-induced motion
The 128-storey Shanghai Tower, known for its twisting exterior, would pose wind engineering challenges regardless where situated. But engineers also had to consider the tower’s location in a seismic and typhoon-prone zone. Extensive wind tunnel testing and aerodynamic form optimization helped mitigate most wind-induced motion, but designers also wanted a tuned mass damper (TMD) to provide an extra guarantee of occupant comfort and serve as a tourist attraction. Use of a TMD means most people will not detect movement at the top of the tower. Their only clue would be watching the gentle sway of the TMD from the observation deck.