Could a skyscraper be durable enough for a place with earthquakes?

Answer 1

Skyscrapers can be built to resist earthquakes, within limits.

However big an earthquake was, you can't ever say there couldn't be one that is bigger. Therefore, it is always possible, at least theoretically, that however large the earthquake your skyscraper is designed to withstand, it could be hit by one even larger which would damage it or bring it down in spite of your efforts.

That said, there are many things you could do to make a skyscraper better able to resist earthquakes. One of the simplest methods, useful for buildings of all types is to simply fasten things together in ways that frames won't pop loose, materials won't fall apart, glass won't fall out, and so on.

One good example is to give up simple masonry in favor of reinforced concrete or other reinforced masonry. Standard masonry is strong and durable; the examples of Roman structures that have endured for literally thousands of years prove that. But while it is very strong when compressed, when stretched it comes apart easily. Placing steel reinforcing rods in concrete (or tying together other masonry in similar ways) will help counteract that.

Another general method is to build on good ground. Some types of ground, notably ground made up by filling lakes (as in Mexico City) or marshes or waterfront (as in San Francisco) tends to become liquid when shaken by earthquakes. It doesn't much matter how solidly you build if your building rests on ground that's going to flow out from under it when the earthquake hits. Avoiding building on such ground, or building a foundation that goes deep to solid rock beneath bad ground, might be ways to avoid these problems.

Skyscrapers and other large buildings have sometimes been "shock-mounted" on foundations that incorporate springs and rollers. This system acts as shock absorbers to cushion the building from earthquake shocks. In addition, some skyscrapers have movable counterweights built in on a higher level, to help damp out any swaying that might occur; this might be useful for both earthquakes and major storms.

In short, a big enough earthquake is going to bring anything down, but if you know how big the earthquake will be-- or can guess successfully!-- you can take measures to harden buildings against it. Even if the buildings are skyscrapers.