Tag Archives: engineering

How do wooden buildings hundreds of years old still stand

A Japanese Pagoda

A pagoda is a tall and often very old structure built entirely out of wood.

They are common in Japan and some are extremely old. For example “Horyuji pagoda in Nara was built in 607 and is thought to be the oldest multi-storey wooden structure in the world.”

The Economist has an article explaining just how these structures have managed to survive hundreds of years of typhoons and earthquakes.

Summary:

  • To withstand very heavy rains the eaves are extended way beyond the building’s width – about 70% beyond!
    • This prevents rain water from weakening the foundations
  • The floors are not actually attached. They are simply stacked on top of eachother and held down by the weight of the heavy tiles on the roof
    • This allows each floor to move during an earthquake without breaking up
  • There is a central pillar known as a shinbashira that (normally) rests on the ground
    • This pillar prevents the shifting floors from sliding off eachother and also transmits the energy into the ground.

It’s a fascinating article and a good example of why The Economist is so great.