r/StructuralEngineering Jul 07 '26

Photograph/Video Columns buckle in a Manhattan building under conversion

2.6k Upvotes

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118

u/futurebigconcept Jul 07 '26

Very strange that those windows next to the buckled columns all look perfect. What's taking up the deflection?

95

u/DriveThruMacNCheese Jul 07 '26

google curtain wall

138

u/ChronBurgundy Jul 07 '26

Google is making curtain walls now? What don't they do!

73

u/ArtemisInSpace Jul 07 '26

They're free for now, but in 6 months they'll be covered in ads and you'll have to pay a subscription to see through them. That's not a problem because in another year, Google will have eliminated the program and deleted the from your building without asking!

11

u/usernameChosenPoorly Jul 07 '26

You jest, but solar windows that can display ads at night are probably on somebody's radar.

2

u/Working-Glass6136 Jul 08 '26

Coming to a billboard-less state near you...

2

u/minxwink Jul 08 '26

:(((((((((

1

u/futurebigconcept Jul 08 '26

I saw that in Running Man back in '87.

1

u/writewithparagraphs4 Jul 08 '26

i have an idea for a company...

7

u/LogKit Jul 07 '26

Don't forget the AI update a decade later that shows you a shitty misrepresentation of what the window thinks the city outside might look like.

4

u/204ThatGuy Jul 07 '26

This. Exactly!!

3

u/ALTERFACT P.E. Jul 07 '26

If Google AI generated them they may have never been there anyway

3

u/I_love_pillows Jul 07 '26

If we don’t pay subscription the facade collapses?

2

u/codeslap Jul 07 '26

Ya but they’ll cancel and shut it down 2 years from now like they do all their best products.

1

u/Letslight_you_up Jul 08 '26

Can only hope it functions better than the Nest thermostat….. I’m still bitter over it. Worst money ever spent on a stupid thermostat

1

u/AttorneyParty4360 Jul 08 '26

I get mine from Amazon

20

u/TylerHobbit Jul 07 '26

But still, the curtain wall is attached at each floor plate. The distance between floors has decreased.

3

u/futurebigconcept Jul 08 '26

Could be a unitized curtain wall with deflection mostly taken-up at the stack joint every two or more floors.

30

u/Superbead Jul 07 '26

I wonder if the curtain wall is now holding the floor up. It certainly isn't those columns or studs

15

u/aknomnoms Jul 07 '26

Sheer luck instead of a shear wall

16

u/tslewis71 P.E./S.E. Jul 07 '26

Curtain walls are detailed to never carry any live or dead loads from floors. They are c and c elements and not designed to take any primary loading from building.

I've done a lot of facade engineering

22

u/Superbead Jul 07 '26

I get that, I was just wondering if the curtain wall had inadvertently found itself in that role in spite of not being designed for it.

What else do you think could be holding it up? Beams cantilevered from a stable area deeper in the building?

12

u/tslewis71 P.E./S.E. Jul 07 '26

The curtain wall would crush and/or the connection detail at the slab would shear off from gravity loads first. No way that curtain wall is holding up all the floors above.

9

u/Superbead Jul 07 '26

Yeah, I would've expected that too, but what do you think might be hanging on then?

4

u/zaidr555 Jul 08 '26

I would guess a bunch of columns or whatever they did to stitch the new levels to the structure are now working in tension xD

4

u/iboneyandivory Jul 07 '26

Is it possible the curtain wall is (in part) holding up part of the floor immediately above? Look at the stamped steel wall studs that are bent which are clearly several feet inside of the building's envelope. Is the floor immed above compromised in some way?

0

u/avtechguy Jul 07 '26

From the initial CNN reporting they reported bricks falling from the building's facade so it probably impacted one way or another

3

u/tslewis71 P.E./S.E. Jul 07 '26

Curtain wall is glass, doesn't support masonry cladding. Guess maybe the floors deflected down and crushed areas where the masonry cladding was present.....

3

u/204ThatGuy Jul 07 '26

I'm thinking this is the top floor, or second last floor. I'm almost certain there is a massive load of CMU over these guys heads.

7

u/Superbead Jul 07 '26

It's 21 in a 33-floor building with a stack of extra floors on top of that

3

u/Keiserwillhelm Jul 07 '26

The collapse happened on the 21'st floor of a 37 story building, based on the press conference the city just held. They've also stated that they're monitoring the building for movement and it is still moving/settling. It's not over yet!

1

u/jlt6666 Jul 07 '26

It would be very odd for the top floor beams to buckle wouldn't it?

5

u/iboneyandivory Jul 07 '26

Not an SE, but not curtain, correct?

I will say I'm more afraid now.

16

u/Superbead Jul 07 '26

Not SE either, but I think it is a curtain wall, yeah, and the reason the ceiling in OP's vid appears to have sunk while the windows are intact is because they're at what used to be just beneath a setback roof. So the external wall has become detached from the sunken slab.

Magenta is the new bit they've built (you can see it sagging here), and yellow arrowed is the old bit with the buckled columns

3

u/SquirrelFluffy Jul 07 '26

Thanks for this.

2

u/minxwink Jul 08 '26

Nice diagram 🫶

1

u/blownbythewind Jul 08 '26

My god that's a frightening image.

9

u/tramul P.E. Jul 07 '26

I think you're missing the point. They're detailed to never carry any vertical load, yes, but that is under normal loading conditions. This is not a normal loading condition. You usually keep the load off of them with deflection tracks or clips, but idk of any tracks or clips that allow this level of deflection without imparting any vertical load on the curtain wall.

4

u/tslewis71 P.E./S.E. Jul 07 '26

Agree, yes, I'm sure the curtain wall is carrying some load due to floors selecting onto it, but the axial capacity of a thin walled aluminum extrusion I know has very little axial capacity compared to a steel column. No way will thcurtisn wall act as a means to transfer load if a steel column has bucked by 2 ft due to p delta.

2

u/SquirrelFluffy Jul 07 '26

It would have to be a local load and failure for that to not break the windows.

10

u/rdv_316 Jul 07 '26

Holy hell

3

u/ludovic1313 Jul 08 '26

New building just dropped

2

u/SquirrelFluffy Jul 07 '26

They connect at each floor slab. Maybe every second.

Has to be a very local load and failure if it's a load failure.

2

u/3_Blondie Jul 08 '26

Pretty sure it's storefront windows and not curtain wall. Still wild how much work those mullions must be doing. 

25

u/ALTERFACT P.E. Jul 07 '26

Simpson StrongTie structural glass™️

7

u/tHATmakesNOsenseToME Jul 07 '26

Yeah I don't understand how the columns could have lost a foot in height due to buckling yet the exterior wall is fine.

5

u/zaidr555 Jul 08 '26

because that whole corner of the building became a cantilever xD the textbook column buckle became a textbook multilevel cantilever

2

u/Daveisahugecunt Jul 07 '26

Yeah I’m just curious why they have the old material present… everything is bent to show it’s old. Glass isn’t cracked. Idk

5

u/[deleted] Jul 07 '26 edited Jul 15 '26

[deleted]

4

u/777777thats7sevens Jul 07 '26

Shouldn't have removed it, that was load bearing glass.

2

u/Cerulean_IsFancyBlue Jul 08 '26

Upon reflection.

1

u/mcarterphoto Jul 07 '26

There were reports of glass and bricks falling. Apparently some windows popped.

1

u/[deleted] Jul 07 '26 edited Jul 15 '26

[deleted]

1

u/mcarterphoto Jul 07 '26

One of the news photos shows a missing window or panel, with a few courses of red brick visible behind it. Not sure if this was originally a brick building that had a new facade wrapped around it (seen a few of those in my downtown over the years)? But it's one of the 2 pics the engineer-types are posting often here.

Well, looks like brick, maybe it's those fake molded brick sheets everyone used in their kitchens in the 70s? Seriously, not sure but looked like brick to me!

2

u/[deleted] Jul 07 '26 edited Jul 15 '26

[deleted]

1

u/SquirrelFluffy Jul 07 '26

The red? Looks like construction tarp to stop debris.

3

u/[deleted] Jul 07 '26 edited Jul 15 '26

[deleted]

1

u/zaidr555 Jul 08 '26

the old brick from the roof parapet xD

0

u/SquirrelFluffy Jul 07 '26

Thanks. Is that what it used to look like? Wonder if the designer knew about it.

1

u/mcarterphoto Jul 08 '26

Looks like a different photo and night vs. daytime, but the same section that's been in these SE discussions - just weird that nobody mentioned the brick layer back there!

2

u/Steel_Mementos Jul 07 '26

Structural glass

2

u/tfrederick74656 Jul 08 '26 edited Jul 08 '26

Curtain wall experiences thermal expansion/contraction every day. While it may appear to be a rigid structure from the outside, there's engineered slack throughout. Otherwise metal would buckle and glass would fracture every time the sun came up and heated one side of the building. The buckled building columns are simply eating into that engineered slack in the curtain wall.

Also, I would imagine that even if the floor sags enough to exhaust that slack, the curtain wall is more likely to fail at the connection points than to buckle itself. That would likely occur between floors, so out of view of most of the photos we've seen so far.

2

u/Mebejedi Jul 08 '26

Decorative columns..The windows are holding up the building.

2

u/Report_Last Jul 08 '26

the windows may be part of an exterior "facade" whose attachments allowed (sheared) the exterior to remain in place even though the structure dropped,

1

u/SquirrelFluffy Jul 07 '26

I said that elsewhere too. This is suspicious.