Taipei 101’s impressive tuned mass damper

Taiwan was struck on Wednesday, April 3, 2024, by the most powerful earthquake it has experienced in the last 25 years, but Taipei 101, once the world’s tallest building, can be seen in video footage hardly swaying during the event.

The 7.4 moment magnitude earthquake caused widespread destruction in Taiwan, including loss of lives, more than 100 buildings damaged, landslides and widespread liquefaction.

However, Taipei 101, can be seen on videos easily withstanding the force of nature, and that is mostly due to the ingenious design of the damper it contains between its 87^th and 92^nd floors.

Taipei 101, as the name suggests, is 101 stories tall, reaching a total height of 1,667 feet, while its construction lasted from 1999 to 2004, and it was the world’s tallest building from 2004 to 2009.

The tower, that is still Taiwan’s tallest skyscraper, had to be designed to withstand tremendous amounts of earthquake and hurricane imposed forces, as these phenomena are quite common in the area.

Because of this, the tower is fitted with outrigger trusses, which run from its core to the outer columns, enhancing its stiffness.

In addition to this, a 660 metric ton pendulum like tuned mass damper is installed at the tower’s center, between floors 87 and 92, which is able to counteract imposed forces by swaying back and forth, as much as 5 feet from side to side.

The damper can reduce the skyscraper’s swaying by 40% during imposed excitations, while it is cylindrical and entirely constructed of steel.

Moreover, it consists of 41 5-inch-thick steel plates, which are welded together to form the golden sphere damper.

The sphere hangs from 92, 138 feet long, 3.5-inch-thick cables, and is constrained by a bumper ring that limits its horizontal movement to a maximum of 59 inches.

Last but not least, Taipei 101 also owes its earthquake resilience to its foundation design, which includes 380 piles, reaching as deep as 100 feet.

Watch the videos below, to see how Taipei 101 responded to the recent 7.4 Mw earthquake, as well as how its damper worked during a 2015 category 5 hurricane, and another 6.8 Mw earthquake.