TOKYO -- General contractor Taisei has teamed up with Kayaba System Machinery to devise an earthquake shock absorber for densely packed urban centers.
In many parts of major Japanese cities, five- to 10-story commercial buildings stand side by side with only 20-30cm of space separating them. Such heavy concentrations can be seen in Tokyo's Ginza and Shinjuku districts, as well as Osaka's Umeda and the areas around Nagoya's main train station.
Conventional quake absorbers require at least 60cm gaps, allowing enough wobble room to absorb a seismic impact.
The new absorber uses the viscosity of oil inside a massive hydraulic cylinder to sponge up shock. The equipment will adjust its shock-absorbing capacity depending on the size of the earthquake, limiting the building's deformation while preventing clashes with neighboring structures.
For milder shakes that occur often in Japan, the hydraulic equipment will rock the building slowly to shield residents and belongings inside. When a more severe quake hits, the shock absorber will significantly curb building deformation.
Although the price of the new equipment will be about 50% higher than what is currently available, the total cost will likely be similar considering the need for fewer units per building.
The equipment will be introduced at a Taisei technical center in Yokohama this spring, then eventually released for sale to other companies.