Take for example the Taipei 101 Tower:
– 508.2 meters high
– Weighs 700,000 tons
– Ground floor is 57×63.5 meters, which is 3619.5 m²
– That means an area of 3619.5m² has to hold up 700.000 tons, which is ~193 tons per m² which is 193.000 kilograms per m²
I don’t know but 193.000 kilograms feels like an unbearable crushing all-pulverizing weight to me.
Obviously it works since the Taipei 101 tower and other huge buildings exist, but intuitively I don’t understand how the bases of large and tall buildings don’t instantly pulverize under the weight of everything above it.
In: 1790
There are two things to understand.
The first is that most materials are very strong when under balanced compression. You can think about how the head of a nail when struck perfectly flat will drive straight into wood without bending, but if you hit it off-center or at an angle, the head will deform and the shaft will bend.
The second is that skyscrapers are not a stack of floors each pressing down on the one below them. Each floor puts all of its weight on the steel beams that extend straight down from top to bottom. The ceiling on the bottom floor is not bearing any weight from the floors above it. Only the steel beams experience that force. To visualize this, if you removed every other floor so that each one was floating in the air except for steel stilts, the structure would stand without a problem.
The ground is actually much weaker than the steel beams that support the tower, so a LOT of engineering goes into anchoring the building so the ground beneath won’t fail, depending on the local geology.
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