Partial Floor Collapse 2

[dik]

Dozens of people have been injured after as section of a balcony gave way at the stock exchange in Indonesia’s capital, Jakarta. A national police spokesman told Agence France-Presse that 75 people had been injured. There have been no reports of deaths thus far.

Scores injured after floor collapses at Indonesian stock exchange


link:

https://www.theguardian.com/world/v...ian-stock-exchange-floor-collapses-cctv-video

 

[racookpe1978]

Odd. The collapsing section (first section to fall) was actually the least loaded (fewest people per square foot) and showed almost no deformation or sagging. Perhaps the highest loading was on the deck(s) above the camera view, or the deck(s) below?

The collapsing deck (those decks in the camera view) broke nearly completely clean of the wall.

 

[LittleInch]

This one shows a bit more what happened. A bunch of students are walking fairly evenly spaced out then bunch together to maybe look at something.

https://www.channelnewsasia.com/new...stock-exchange-collapses-more-than-70-9862074

So I reckon 50 odd people at 70kg each on an area about 10m2 = 70 psf. Is that a good number??

The supporting struts look pretty weedy to me...

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[jayrod12]

It looked like the failure was at the top of the supporting struts. So perhaps the connection at the top let go? Welds in tension or inadequate bolt sizes/quality?

 

[hokie66]

I didn't see any struts, but agree the hangers failed above. Almost all failures of balconies/decks are caused by connection defects.

 

[JAE]

I kept thinking - "Hyatt Regency" when I saw that video. The cause is most likely very different.
But I do recall some discussions after the Kansas City HR collapse where engineers were suggesting that any occupied hanger-type structure carry safety factors of at least 10.

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[IRstuff]

It doesn't look to me that the joists were actually load bearing capable. The after picture does not show any openings where the joists would have been anchored to the rest of the building. Looks to me like the balcony was just sort of hung on the wall

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[TheDW]

Preliminary report has the cause being 'loose or corroded bolts'

https://www.archdaily.com/887207/lo...age:d_flagship3_feed;OEAaxtynThK0XOI9w99E1g==

 

[hokie66]

Connections to the wall may have been tenuous, but the video shows that failure of the hangers precipitated the collapse.

 

[IRstuff]

I haven't seen any other videos, but it's not clear to me that it was a hanger that gave way first. The wall connection failure occurred almost simultaneously with the hanger. Clearly, this balcony was highly under-designed, to the point that if the wall connection even slipped a little, the hanger would snap immediately. There is a guy under the "6" in the time stamp whose head drops at almost the same time that the hanger side drops.

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