Japan’s Amazing Earthquake Technology!

TOKYO – Japan sits on an earthquake belt that has resulted in some of the most destructive quakes in history, but in recent times no modern high-rise buildings have suffered any damage, attesting to their sophisticated quake-resistant construction.

In fact, Japan is noted for having the world’s most advanced quake-resistant technology, and boasts over 500 buildings that are 100 or more meters high, none of which has ever lost as much as a window.

What is not generally known, however, is that the basis for this technology was discovered and was in use more than 1200 years ago.

Even more surprising, perhaps, is that the technology was first used in the construction of huge Buddhist temples and high-rise pagodas—a pagoda being, a many-storied Buddhist tower that originated in India, moved to China and Korea, and finally to Japan around 585 A.D.

Pagodas, built in the compounds of Buddhist temples, are both symbols of Buddhism and storage towers for sacred religious objects. The first pagodas in Japan were built entirely of wood, and had from three to five stories, topped by a spire that made them look even higher.

The 5-storied pagoda on the grounds of the Horyu Temple in Nara, built in the 6th century, undulates like a “snake dance” when an earthquake occurs, with the central pillar swinging like a long pendulum. The temple itself is believed to be the oldest wooden building in the world. The nearby Todai Temple, constructed between 724 and 749, is recognized as the largest wooden building in the world.

Both the Horyu and Todai temples and their adjoining pagodas have suffered some earthquake damage since they were built, but none have ever collapsed.

Architects and engineers who recently supervised repairs on the Toshodai Temple in Nara, built in 759, were well aware in advance that it had withstood many quakes in its 1,245-year history, but they were nevertheless amazed at the sophistication of the technology that made its survival possible.

The Takenaka Corporation engineer who supervised the repairs said that the temple construction consisted of wooden beam joints encircling huge pillars, which allowed the different parts of the building to shift slowly during an earthquake, absorbing the seismic vibrations.

He added that the joints of the large pillars supporting the tile roof of the huge temple absorbed the shock of earthquakes and allowed the pillars to tilt, but once the shaking was over the pillars returned to their upright position.

While various other types of earthquake-resistant technology have gone into the construction of high-rise buildings in Japan since the 1930s, the first building to make use of the ancient temple and pagoda technology was the 27-story, 130-meter-tall Umeda DT Tower in front of the JR Osaka Station, completed in 2003.

The new tower uses a hybrid, base-isolated, system combining three shock-absorbing devices between the second and third floors. The 30,000-ton weight of the building’s upper floors is supported on 12 linear “riders.” When an earthquake occurs, the upper portion of the building slides back-and-forth on shock-absorber devices, reducing the impact of the tremors by approximately 50 percent.

The Takenaka engineer said the difference between ancient Japanese builders and their Western counterparts illustrated a fundamental difference in Asian and Western philosophies.

He pointed out that early Westerners built “hard” unmoving structures of stone in an effort to resist the forces of nature, while Japanese buildings were constructed to absorb the energy of nature rather than resist it.

The huge Marunouchi Building in front of Tokyo Station, which opened in 2002, also uses shock absorbers to protect it from earthquakes. Its dozens of shops and restaurants, the latter on its upper floors (with fantastic views of the Imperial Palace Grounds and central Tokyo), made it an instant tourist attraction.

Japan’s advanced earthquake technology has made its high-rise buildings among the safest in the world.

Copyright © 2007 by Boye Lafayette De Mente
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ABOUT THE AUTHOR
Boye Lafayette De Mente has been involved with Japan, Korea, China and Mexico since the late 1940s as a member of a U.S. intelligence agency, student, journalist, and editor. He is the author of more than 50 books on these countries, including the first books ever on the Japanese way of doing business: Japanese Etiquette & Ethics in Business, first published in 1959, and How to Do Business in Japan, published in 1961.

To see a complete list of his titles [each one linked to Amazon.com’s buy page], go to his personal website: http://www.phoenixbookspublishers.com/.