Typically, land is not “red zoned” as it was in Christchurch, meaning owners can no longer build there. In Japan, it is up to owners to fix buildings if they can. The advantages are clear: A building can be saved for perhaps as little as $30,000, which is far cheaper than knocking it down and rebuilding.
Also in Tokyo, we visit an experimental house called Chisuikan. Owners, Kozo Keikaku Engineering, call it “the world’s first three-dimensional seismic isolation building.” The name is derived from there words: Chi (“knowledge or intelligence”); Sui (“seasoned and excellent technology”); and Kan (“building”).
In the basement, massive seismic isolators will help the building survive a big tremor. If a quake struck now, we would be in one of the safest places. The isolators incorporate a steel trestle and laminated rubber bearings. These form a horizontal seismic isolation device. A slider provides a shear force transmission device, and an air spring provides a vertical seismic isolation device. Cross-coupled pipes connect two oil dampers.
Engineer Dr. Osamu Takahashi says the seismic isolators are a significant advance. He says he was influenced by technology originally developed by Kiwi engineer, Dr. Bill Robinson, in the 1970s. What makes theses new isolators a step forward from previous base isolation technology is their ability to handle both vertical and horizontal movement in an earthquake.
Yes, they are expensive, but a lot cheaper than demolishing a building and starting again. This technology saves lives, and enhances a building’s value. Many public buildings in earthquake areas around the world already use base isolation technology, including government buildings, hospitals, disaster control centers, and power plants.
I am impressed with Japan’s earthquake technology, both old and new. Timber is already recognized as an excellent building material. If Japan’s wooden temples and farmhouses can last for hundreds of years, so can buildings in other parts of the world. New innovations in seismic technology also have considerable potential.