Mitsui Fudosan Co., a major real estate company, will retrofit its 210-meter-tall Shinjuku Mitsui Building in Tokyo with a set of six rooftop counterbalancing weights, each weighing 300 tons, to offset swings from a major quake.
The ¥5 billion installation should halve the swings that typically accompany a big earthquake as the cable-suspended weights move in the opposite direction to the building.
The weight of the equipment is around 3 percent of the entire building and does not pose a significant strain on the structure, which was constructed in Shinjuku Ward in 1974, the company said.
Mitsui Fudosan said the building is quake resistant and the weights are in response to concerns raised by tenants after the March 2011 earthquake shook the building by as much as 2 meters horizontally.