By now, we can all appreciate that the miracle of Japanese earthquake engineering prevented the Great East Japan Earthquake from killing millions rather than thousands (the radiation emanating from the Fukushima nuclear plants is another matter). But earthquake-proof buildings, how do they work?
The architecture gurus at Architizer have stepped in to clarify matters, with this handy-dandy infographic. While it’s a bit heavy on the technical jargon, it’s nonetheless pretty great. Let’s break it down into a few easy pieces.
The problem with earthquakes is that they create a wave of forces, all pushing on a building from one direction. Ergo, the basic strategy for counteracting their forces is to push the other way.
There’s two basic ways of doing this. One, a so-called mass damper, is pretty high-tech. It consists of an extremely heavy weight attached to the top of a building, which sways back and forth. It knows which direction to sway based on sensors that detect which way an earthquake’s waves are coming from:
The second type of earthquake-proofing, a base isolator, resides in the foundations, rather than the roof, and takes advantage of the fact that earthquakes shake buildings from the ground up.
The magic happens in the isolator unit, a large piece of rubber that separates the ground beneath a building from its supporting pylons. It works in two ways: first, by creating a buffer zone that soaks up earthquake forces that would otherwise just ripple through a building’s foundations. But it can’t absorb all those forces, so it also acts as a spring, compressing under pressure and then expanding in a direction opposite the earthquake’s, to counteract its impact.
And then there’s a matter of cost. It’s not quite as much as you think, but it’s high enough that it only makes sense in earthquake-prone regions:
[Click here to see the full infographic]