Shenzhen China SEG Plaza
Skyscraper got the wobbles. Building evacuated and officials are confused.
No Mystery I am afraid. Vortex Induced vibration (VIV) it was.
This thing is a nice cylindrical shape. All it takes is a steady wind at a particular speed. Every building has a natural frequency of vibration in several modes. If that frequency matches the rate of vortex wake formation you get a dance. Cylinders make the best vortexes.
I design industrial stuff and have to check that all the time.
For buildings it is actually very tricky and expensive to test and deal with. There is a famous (expensive) engineering firm in Toronto called RWDI that consults on VIV. Typical treatments are mass dampers and even tanks of water high up in the structure to absorb the vibration energy.
In Taiwan the Taipei 101 skyscraper they have a huge metal ball on the top floors. They even give tours and have a mascot. Look up Baby Damper. They spent the money.
I can see how Chinese developers would want to skip that part. Too expensive to get foreign engineers involved. Oh and the value of floor space up high is too much to waste on big dampers or tanks of water. Waste of money! I have been in such meetings. Money outranks science you know.
If they want to fix it it is going to cost a lot. First they have to hire foreigners and then they will have to give up a few floors of office space and figure out how to put something very big and heavy where there is no way to support it. Fun times. Or just hope the wind does not blow at 32 kph again.
