One thing you might be wondering: just how do these so-called "earthquake-resistant" buildings work? An article from The Independent (U.K.), published in 1995 following an earlier Japanese quake, outlines the basic design strategies that went into many Japanese buildings and explains the details of how the country has been bracing for disaster for a long time:
There are three main types of "earthquake proof" building structures, all used in Japan over the past decade. The first has a heavy concrete weight on the top of a building that, activated by computer-controlled dampers, is shifted across the roof to counteract the force of the earthquake; however, a power cut could stop this sophisticated system working. The second employs shock absorbers, normally a sandwich rubber composition that acts as a form of suspension; this is suitable for buildings up to 15 storeys.Read the full story at The Independent.
The third method, represented by Foster's Century Tower in Tokyo, is the eccentrically braced frame. "This", says Ed Booth of the engineers Ove Arup and Partners, "has steel braces providing stiffness for moderate earthquake motions, but a sacrificial ductile shear link between braces designed to yield in an intense earthquake, absorbing seismic energy and acting as a fuse which prevents the braces from buckling."
"But, earthquake engineering", adds Mr Booth, "is still a relatively new field. During this century more than 1.5 million people have lost their lives as a result of earthquakes and the vast majority of this toll because of buildings that have collapsed through unsuitable design."
"I telephoned my parents in Kobe", says "Mog" Morishima, a Japanese architect working in London, "and they tell me that many of the new buildings on Port Island, a major land reclamation project in the Eighties, have survived. These include the Port Opia Hotel, the tallest building in the area. This is where you can find many new fashionable buildings designed by architects like Tadao Ando and Frank Gehry; it seems that new methods of construction and the new building regulations established in 1971 and revised in 1980 have saved many buildings and, so, many lives."
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