The Guardian: Panic as 300-metre-high skyscraper wobbles in China

KGMtech said:
Without any earthquake, it's hard to understand what is going on. The video was useless for showing any wobble...just panicking people.
Maybe the foundation shifted?
Click to expand...

I agree. I couldn't make out any wobble with that video. But by the look of those panicking, I don't doubt it.
 
Late 90s early 2000s are the boom time in China. Buildings from back then likely aren't the best quality and things must go up fast. I have relatives whose apartment building were done in the mid 90s and they would have concrete chipping off left and right already. Whereas my wood frame home in SF Bay from the same era still look "like new" in comparison.

That 72F building is a computer mall, sort of a local attraction. A few years ago another building collapsed in the same city but closer to the border to Hong Kong. It was an early 90s building and everyone evacuated on time so no fatality. I heard after the collapse the price went up because it was prime location and you don't need any eminent domain or criminals to evict squatters refusing to sell, so as a developer's green field it is pretty valuable.

I don't buy the government official story of "it is just an oscillation or harmonics resonance". I'm not going into that building for another 2 years.
 
NYC had a scare years ago based on a design flaw of the citibank building. A serious wind could cause the building to tip over.

The flaw was fixed "after hours" by welders facilitated by the exposed structural steel on the inside of the building

Design flaws can exist even when architected by experienced firms.

 
simple_gifts said:
NYC had a scare years ago based on a design flaw of the citibank building. A serious wind could cause the building to tip over.

The flaw was fixed "after hours" by welders facilitated by the exposed structural steel on the inside of the building

Design flaws can exist even when architected by experienced firms.

Click to expand...

I remember reading that, they were paying overtime to have welder welding up all the bolts to make it stronger before a hurricane hit.

This building in Shenzhen was from decades ago, if it suddenly start swaying it is everyone run for your life time.
 
PandaBear said:
I don't buy the government official story of "it is just an oscillation or harmonics resonance". I'm not going into that building for another 2 years.
Click to expand...
Harmonic resonance is a real problem. If the wind hits the natural frequency of the building, then you get the wobble. It might need some additional work to change its natural frequency. Could also be a construction problem, probably requires closer inspection that will take some time.
 
Wolf359 said:
Harmonic resonance is a real problem. If the wind hits the natural frequency of the building, then you get the wobble. It might need some additional work to change its natural frequency. Could also be a construction problem, probably requires closer inspection that will take some time.
Click to expand...
Suddenly starting after 20 years?
 
PandaBear said:
Suddenly starting after 20 years?
Click to expand...
Harmonic resonance happens at a certain frequency, it may take just the right wind speed or loading to hit the right parameters. Otherwise the wave just cancels out instead of amplifying. Basically when you add two waves together, it doubles, when they're out of phase, they can cancel out. They might need to do something to the building to adjust the natural frequency.
 
Wolf359 said:
Harmonic resonance happens at a certain frequency, it may take just the right wind speed or loading to hit the right parameters. Otherwise the wave just cancels out instead of amplifying. Basically when you add two waves together, it doubles, when they're out of phase, they can cancel out. They might need to do something to the building to adjust the natural frequency.
Click to expand...
I know how harmonics work, but on a normal non stormy day it happen only after a couple decades is statistically unlikely. In theory this should have happened long ago if it is just harmonics. Unless something loosen up and the building isn't the same as before, which is also kind of scary.
 
that area of china is changing all the time. i wonder if they put up a new building or the ground is shifiting due to other issues like the subway.
 
Ground subsidence can be a real issue in certain places like Mexico City. Over twenty years, even a subsidence rate of <1 cm/year can lead to a lot of stress on a tall building that suddenly shifts to relieve the accumulated stress. Placing the enormous weight on the ground with very tall structures is bound to cause issues in some of them over time.
 
The original World Trade Towers in New York City did a bit of swaying when the wind kicked up. I was on a top floor one day and felt it, relatively minor swaying but if not used to it you would notice.
 
72F building will sway to the wind if it is designed for since the first day. I was on one a few years back and you can probably put a wind turbine on your balcony and provide 1/2 of your home's energy need, and it sway 1cm left and right constantly like you are on a boat.

The problem with this tower is it suddenly started after 20 years. It was build in 96 and it suddenly start in 2021. That's the panic.
 
PimTac said:
The views must have been spectacular.
Click to expand...
77623910-DC87-4853-BB26-4AF78E3E5571.jpeg
2D033651-4176-4F1A-BB13-92E1098B0346.jpeg
 
Looks like the two towers on the top are oscillating in opposite phase to each other.
 
You must log in or register to reply here.

Similar threads

GON
  • Locked
China can wait. The Army’s focus should be Europe.
12 13 14
Replies
272
Views
7K
M56959
GON
China's producer prices plunge the most in seven years as deflation hangs over economy
3 4 5
Replies
83
Views
2K
PimTac
buster
US, Philippines vow joint defense ‘anywhere in the South China Sea’
2 3 4
Replies
60
Views
2K
PimTac
OVERKILL
Cogeneration in China - Solar production
Replies
9
Views
489
Cujet
C
TSMC needs to hire 4,500 Americans but it's "brutal" corporate culture is getting in the way
3 4 5
Replies
96
Views
4K
CanAmAndMore
Top