Japanese Pagoda Is Model For Earthquake-Safe Buildings
With ever more frequent earthquakes and typhoons devastating cities around the world, it’s time to start taking antiseismic structures seriously.
And the Japanese pagoda is the perfect example of ancient, forward-thinking engineering, writes expert Douglas P.Taylor on NY Daily News. When concrete-heavy office blocks collapse, flimsy wooden pagodas in Japan have stood upright for centuries, due to their ingenious construction.
Apart from the fact that it would be kind of awesome if we lived in Pagoda-like buildings, it would also be safer.
In the last 1400 years only two Japanese pagodas have collapsed from shaking in the land of earthquakes.
The iconic Horu-ji pagoda temple in Japan has survived unscathed 50 earthquakes of magnitude 7.0-plus during its 1410-year lifespan. It is described as “a monument of stability in a land of seismic instability”.
So what’s the secret?
Builders have placed a central pillar within a shaft in the centre of the building, called Shinbashira. Shinbashira doesn’t actually support any of the building’s weight, but acts like a shock absorber and buffer between floors. Moreover, the load-bearing vertical beams aren’t connected to each other, and their individual floors aren’t connected to their neighbors either.
This means that when an earthquake strikes, the floors move independently and fluidly in what has been described as a “snake dance”.
The engineering secrets of Japanese pagodas originated in neighboring China. The super-smart Chinese have used a remarkable 2000-year-old building technique called “dougong” to build earthquake-proof structures. All these colourful interlocking brackets you see in traditional Chinese structures aren’t there just because they look pretty. Dougong uses interlocking wooden beams to support the traditional Chinese hanging roofs by sharing the structure’s weight.
Why is this important?
As Taylor explains, the current building codes for new buildings in the U.S. and worldwide only require collapse prevention designs. They do not require "performance-based designs" that would make the buildings perform much better in an earthquake.
Let’s not forget ancient architecture. Sometimes the solutions to modern problems are best found in the wisdom of antiquity.
Image: Creative Commons