Shenzhen SEG plaza (Electronic Market) building shaking - Page 1
Forum section: electronics / general

author: agtrbt
author_rank: Contributor
timestamp: May 23, 2021, 05:00:06 am
content: https://www.abc.net.au/news/2021-05-20/footage-shows-shaking-of-seg-plaza-in-china/13351842https://news.rthk.hk/rthk/en/component/k2/1591949-20210521.htmAll their circuits are physically oscillatingSuch building vibration has relapsed for at least three days I think. That would be rather disturbing because the building resonance was so noticable.

author: G7PSK
author_rank: Super Contributor
timestamp: May 23, 2021, 03:25:15 pm
content: For a while in the 1980's one of my sisters lived on the top floor of a tower building in Knightsbridge London UK. In windy conditions the building swayed enough to notice and be able to see water in a glass moving from side to side. As far as I know the building is still there overlooking Harrods.

author: coppice
author_rank: Super Contributor
timestamp: May 23, 2021, 03:43:40 pm
content: Quote from: G7PSK on May 23, 2021, 03:25:15 pmIts common for tall towers to swap a metre or more at the top, but they usually do it so slowly the occupants are barely aware of it, unless they view something something through the windows lined up to make movement obvious.

author: fcb
author_rank: Super Contributor
timestamp: May 23, 2021, 04:22:56 pm
content: It's just a giant metaphor for the electronics industry right now.

author: mikerj
author_rank: Super Contributor
timestamp: May 23, 2021, 07:45:38 pm
content: Does seem odd that it's been up with ~21 years and this is the first time it's happened. What are the chances that some structural element has failed?

author: Yansi
author_rank: Super Contributor
timestamp: May 23, 2021, 08:01:06 pm
content: Or some HVAC/RTU sucked up a rag in its fan

author: dietert1
author_rank: Super Contributor
timestamp: May 23, 2021, 08:30:33 pm
content: As far as i know these buildings have a large device on top that keeps moving a huge weight horizontally to damp movements of the building. Maybe that machine failed. I remember sightseeing in Sao Paulo no Edificio Triangulo do Oscar Niemeyer built in 1955 when they did not yet have that technology. The movements of the building felt dangerous, just as those old fashioned elevators..Regards, Dieter

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 23, 2021, 08:41:12 pm
content: Yeah I saw that. The oscillation ended up stopping after 3 days without any known reason either.What I've seen it that this building apparently started being built before its plans were fully finished. Also, that upon completion, the roof antennas were shaking so badly that they had to remove them and re-do the antenna installation completely. That's all I've gotten so far.Since there was apparently no external event explaining the shaking, it might be some kind of self-resonance indeed. Triggered by who knows what.There has been a few collapsed chinese buildings in the past. That's not something uncommon over there.

author: james_s
author_rank: Super Contributor
timestamp: May 23, 2021, 08:59:47 pm
content: I recall reading somewhere that the Space Needle in Seattle tends to torque in a strong wind. I don't know anything about the period or magnitude of the oscillation though.

author: Gyro
author_rank: Super Contributor
timestamp: May 23, 2021, 09:53:25 pm
content: ... yet.

author: jmelson
author_rank: Super Contributor
timestamp: May 24, 2021, 02:49:02 am
content: Quote from: Gyro on May 23, 2021, 09:53:25 pmWow, retrofitting a sway damper to a completed building is not a simple job! First, you have to clear out most of an entire floor of the building, and install a 100 ton or so granite or concrete weight on a slider.Really, I think retrofit is impractical, the building has to be built with specific floor structure, etc. due to the weight and forces involved.Jon

author: Raj
author_rank: Frequent Contributor
timestamp: May 24, 2021, 08:30:18 am
content: Is this where the "Strange Parts" guy buys his Iphone components from?

author: AlbertL
author_rank: Regular Contributor
timestamp: May 24, 2021, 04:36:54 pm
content: I'm thinking it's wind vortex shedding interacting with the building's natural oscillation period.

author: floobydust
author_rank: Super Contributor
timestamp: May 24, 2021, 08:53:27 pm
content: What's alarming- it's never been this bad before in the building's 20 year history (including typhoons), and for three days, which I think rules out the usual excuses.I like the one about Coriolis effect with HDD's mining chia bitcoin lol. All that spin spin spin, yeah that caused the shakingUsing sea sand for concrete, which corrodes rebar, fake rebar, rebar that shatters, building something before drawings are finished, building 2.7 floors per day "shenzhen speed", changing the design on the fly - what could possibly go wrong.

author: Gyro
author_rank: Super Contributor
timestamp: May 24, 2021, 09:21:34 pm
content: Quote from: jmelson on May 24, 2021, 02:49:02 amDon't some buildings use water tanks? That might be more practical than hoisting up 100 tons, a sand filled mass might be another alternative.I just picked up on a comment in the link that 3roomlab posted...Quote

author: SiliconWizard
author_rank: Super Contributor
timestamp: May 25, 2021, 05:29:39 pm
content: Rushed building construction was a common thing in the early 2000's in China. So yeah, nothing particularly surprising here. Remember a hotel (admittedly much smaller than the SEG plaza) collapsed last year.https://edition.cnn.com/2020/03/07/china/china-coronavirus-hotel-collapse/index.html

author: mikerj
author_rank: Super Contributor
timestamp: May 27, 2021, 08:09:25 pm
content: Quote from: jmelson on May 24, 2021, 02:49:02 am728 tons for the mass damper in the Taipei 101 building!https://www.popularmechanics.com/technology/design/a16819/tapei-101-mass-damper-record/

author: station240
author_rank: Unknown
timestamp: May 28, 2021, 02:44:50 am
content: Lot of information (and speculation about what it means) in the video and listed in the description.But the important parts:QuoteQuoteQuoteAlso as others have said in this thread, the building does not have mass dampers.