Japanese companies develop 300-ton pendulums that reduce swaying in skyscrapers during earthquakes
| August 15, 2013 |
Two Japanese companies have developed giant pendulums they say, when installed atop a skyscraper, can shorten vibrations and reduce swaying caused by earthquakes by as much as 60 percent.
Mitsui Fudosan, a real estate developer, and construction firm Kajima developed a 300-ton pendulum that, according to a report from CNET, “will act as a counterweight to long-period seismic waves.”
The way the device does this is by swaying in the opposite direction of the seismic wave. For instance, as the seismic wave pushes against the building to the right, the pendulum swings left, counteracting the movement and keeping the building more steady.
The innovation was originally reported by Asahi Shimbun, which says the companies will spend $51 million ($5 billion yen) to install the first of these pendulums at the top of Tokyo’s 55-story Shinjuku Mitsui Building in 2015.
During the 9.0-magnitude Great East Japan Earthquake in 2011, the Shinjuku Mitsui Building saw horizontal vibrations of about 6 1/2 feet. That much motion causes interior damage and can injure those inside.