Engineering for extremes
The Sky Tower is designed to resist forces that would compromise many other structures. The design criteria specified that the tower must remain standing during a magnitude 8.0 earthquake occurring within a 20-kilometer radius. Its foundation and main structural elements were engineered to remain essentially undamaged under these seismic conditions. This resilience is deep underground. The structure rests on a 2.5-meter thick concrete foundation pad, which is supported by 16 reinforced concrete piles, each two meters in diameter, drilled over 12 meters into the underlying siltstone.
Wind presents another significant force. The tower is built to handle winds exceeding 200 kilometers per hour. During such events, the concrete shaft is designed to sway up to one meter without sustaining damage. To counter wind-induced vibrations in the 90-meter communications mast, engineers proposed the use of tuned liquid mass dampers. These devices absorb kinetic energy from the swaying motion, reducing fatigue on the steel mast and minimizing vibrations. For occupant safety during high winds, the tower's elevators are equipped with technology to detect building sway; they automatically slow down or return to the ground floor if movement exceeds predetermined safety levels.