I’m an Arup Fellow specialising in seismic...
You’re stuck on the 25th floor of a skyscraper when a major earthquake hits. What should you do? Well, counter-intuitively for some, you should just be thankful… and move away from any filing cabinets that might fall over.
The fact is that for most earthquakes, tall buildings are usually the safest place to be. In Hong Kong, where I live, visitors often look at all the tall buildings and ask: “What would happen if there were an earthquake?” The answer is that they’d probably be much safer than if they were standing in a low-rise neighbourhood.
This might surprise some people, but there are a few reasons if you know a little about how buildings respond during earthquakes. For one thing, on a practical level, if you’re inside a building with more than 20-storeys, it’s too far to run out into the street when an earthquake hits. You’re definitely safer inside away from falling debris and stampedes of panicking people in the street.
Secondly, modern high-rises, in low seismicity areas, are designed to withstand lateral loads from wind which may be much higher than those from earthquakes. In high seismicity areas they are most likely to have been designed for the seismic motion, and for very tall buildings having a long natural period (or a low frequency) will sway in a non-violent, but still a very alarming way.
In short, unless you happen to be at the epicentre of a really major earthquake or stuck in a very old high-rise, you have a far better shot at surviving than your friends on the ground. Provided you avoid the falling filing cabinet of course.
This is why I’d always opt for a high-rise home over a low-rise alternative in an earthquake zone, even before considering all the other benefits that tall buildings offer for urban living such as providing a city readily accessible by public transport.