A Japanese construction company has tested its latest earthquake damper technology for skyscrapers with a device installed in the upper floors of a building model.
In the March 2011 earthquake that hit eastern Japan, shakings called long-period ground motion swayed ultra-high-rise buildings far from the epicenter, including Tokyo and even in distant Osaka. The prolonged swaying caused damage to ceilings and walls of numerous high-rises.
Construction companies in Japan have been developing technology to absorb seismic energy and reduce vibrations.
On Thursday, the latest technology was tested using a reduced-scale replica at a facility that can reproduce long-period ground motion.
In the test, the device was installed in the upper floors of a building model rather than under it. Damper systems are often set between a building and its underground foundation.
Engineers say the building replica incorporating the new technology showed that swaying on the upper floors were reduced by 30 percent compared to the replica without the technology.
They also say installing the dampers on the upper floors helps to cancel out the swaying in the lower floors and reduces the movements of the entire building.
Placing the dampers on the upper floors also contributes to reducing the number of devices and can create more floor space.
The new technology will be applied to a 43-story skyscraper in Shibaura of Tokyo's Minato Ward to be completed in February 2025. The damper devices with the new technology will be installed on the 34th and 35th floors.
Fukukita Akira, a senior official of Shimizu Corporation's Institute of Technology, says that the upper floors of skyscrapers tend to sway more in earthquakes but the test results confirmed the new technology helped to reduce swaying.
He added that the institute will continue research as the number of skyscrapers is increasing, especially in urban areas.