July 16, 2003
Why do they leave a gap between the balcony barrier and support columns?
In South Korea, they build many standard houses. They are called apartments, and Koreans call them “apaty” for short. Apartments in such houses are located from side to side. On one side of such a house, there are light glassed balconies. On the other side, there are glassed galleries extending from the entrance doors. They are also a kind of balconies, but they are made from two concrete panels –
a horizontal one on which we walk and a vertical one which protects us against falling down.
The balconies are separated in width by vertical support columns. And it looks very strange that the vertical panels are rigidly fastened to the horizontal ones, whereas their sides are not fastened to the support columns. There is a 10 cm gap between them. What is it for?
The thing is that the gap is a simple and fairly effective method of damping shocks during earthquakes. When a shock wave reaches a house and shakes it mightily, the vertical panels of the balconies start oscillating with a different frequency dispersing and dampening the concentrated shock of the underground wave.
Discoordination of the action of the shockwave by frequency can reduce the concentration of its energy.