Saturday, March 26, 2011

Disasters and Safety Code Designs

Disasters, they are luck of the draw from a long tail distribution. When they come, they wipe it out.
All we can do is be prepared for such events. The best way to do it is by enforcing better design codes and reinforcing rules for people's safety.

The recent disaster in Japan has left human being, one more time, thrilled with the power of the nature. Since this is one of the best documented disasters, we all have seen videos of tsunami wiping out the whole village or town. Notably, however, one must appreciate the strength of the buildings. Tall buildings by the side of the water wave stood the stress.

Simply, when water wave meets the shoreline buildings ...
The force per second is

Since the density of water is 1000 kg/m^3, assuming that the velocity of the water is 100 m/s, we can see that every square meter of the building  subjected to a 1m thick water intake is acted by 100 tonnes of lateral force (every second). To help visualize, if the walls were the floors, and elephants were to stand; every square meter was virtually supporting at least 20 adult african elephants! This make me highly appreciate the rules made for building strength.

One of the reason several cameramen survived with the first person videography was because such strong buildings were there to stand the waves. They stood the earthquakes and then tsunami.

We can probably relate the safety design codes with structures in our capitol: Kathmandu. However, that makes me feel dizzy. Lets not do that this time.

Out heartfelt condolence goes to all the people who suffered from the natural disasters.

Tsunamis are shallow water waves []