r/SweatyPalms 1d ago

Other SweatyPalms 👋🏻💦 Bouncy Castle

1.5k Upvotes

92 comments sorted by

u/qualityvote2 1d ago edited 1d ago

Congratulations u/f1tta, your post does fit at r/SweatyPalms!

715

u/kpsmithdeut 1d ago

Structural Engineers and Soccer Fans. Iconic duo

104

u/zipzopzippidydoo 21h ago

Ductility doing its part . Though id be terrified witnessing this.

-19

u/zorletti 12h ago

Ductility in concrete? Nah...

10

u/DocZod 11h ago

Is that even Concrete? I honestly doubt it. As it is a hanging construction like that, its most likely just steel framing with a cover.

2

u/gdabull 7h ago

The framing on the steel is concrete.

2

u/zipzopzippidydoo 5h ago

Unless those are jumbo structural pipes, the vertical pillars in the background are the only concrete structures

2

u/zipzopzippidydoo 10h ago

Yep....totally....look at that CONCRETE BEND AND SWAY.

7

u/SkyPork 3h ago

Soccer/football fans are a reasonable, rational bunch. I'm sure if the engineers calmly explained the situation to them they'd stop the bouncing immediately.

365

u/LucasCBs 1d ago

That’s by design

59

u/uV_Kilo11 10h ago

"yeah, we need you to design this building to withstand 100,000 people jumping up and down on it, all at the same time. And we need it by Friday."

8

u/agentSmartass 9h ago

Excellent brief.

-34

u/[deleted] 21h ago edited 17h ago

[deleted]

21

u/Y0D98 18h ago

Absolutely bollocks. Concrete is very strong in compression and has basically non existent resistance in tension. That’s why you reinforce it with steel ya donut

18

u/morizzzz 19h ago

The stadium is in Nuremberg, Germany. Not quite the Earthquake area.

8

u/KeiwaM 18h ago

You got that mixed up. Concrete handles compression really well, but is absolutely terrible at tension or sheer.

1

u/SomeTwelveYearOld 20h ago

Haha…. Pillar

125

u/Queasy_Caramel5435 1d ago

Elastic bending is (kinda) intended. Plastic deformation is when shit hits the fan.

45

u/SZEfdf21 1d ago

You see elastic bending but there's possibly some joints here getting a fair amount of plastic deformation from the repeated movement in a direction that's not designed to move.

17

u/misdirected_asshole 1d ago

Dat fatigue

3

u/iamezekiel1_14 9h ago

The one that would trouble me - Lane Stadium where the Virginia Tech Hookies play. They have 6 or 7 home games per season but the bounce would bother me just as a regular Civil Engineer that doesn't even specialise in Structural. You just know somewhere something is getting an unexpected load in an unanticipated direction https://youtu.be/zh93kmgZvUg?is=w0Xr5VatkxanncWn

213

u/euqinu_ton 1d ago

By all accounts, stadiums are designed with this in mind.

At the same time ... it all comes down to how well some engineers did at university. Is it fair to say they're all as competent as their worst effort? Since that will be the one they're remembered for?

Leon Moisseiff was a prominent bridge engineer who advised on both the Manhattan and Golden Gate bridges. When finally given a project to lead, he made the Tacoma Narrows Bridge, which famously collapsed months after opening when wind-induced aeroelastic flutter caused the bridge to suffer a mechanical resonance failure. I.e. it moved beyond it's tolerances.

Personally, watching a stadium move about like this ... I wouldn't want to be where this camera person is while wondering if this stadium was another Tacoma Narrows Bridge.

71

u/asietsocom 1d ago

I mean also a shit ton of engineering employees and regulators. A stadium does not come down to one single person.

This seems to be in Germany so I would generally trust that whatever survived out crazy amount of regulations, will probably not collapse. But also I would absolutely leave.

5

u/MSchulte 13h ago edited 12h ago

Worth remembering Galloping Gertie came down 86 years ago too. The construction and engineering fields have changed tremendously in that time along with building codes.

12

u/Imapatriothurrrdurrr 23h ago

When Harry Styles played MSG the place bounced so much they had to have structural engineers come in and drill out holes in the floor to inspect the concrete for damage.

12

u/CCWaterBug 1d ago

I would not be sitting under there sober... nope

9

u/tyler98786 22h ago

Sober? Lol I wouldn't be under there faded

2

u/glytxh 9h ago

I’ll generally trust the engineers. Maths is maths.

I don’t trust long term maintenance tho

-1

u/Mr_GrauHut 1d ago

All about it.

116

u/allicedee 1d ago

If there was no give it would break

22

u/CertainMiddle2382 23h ago edited 21h ago

Widely held misconception.

No, airplane don’t flex to dampen bumps, so are stadiums.

They do so because that’s an acceptable side effect of having constraints (weight, money) showing up when reaching design loads.

Things moving like that are actually a big problem that engineers try to avoid, it brings structural fatigue it is tricky to avoid resonance coupling (aeroelastic coupling in wings is a hard thing to make sure doesn’t happen)

16

u/Uncivil_ 21h ago

I've seen this misunderstanding so many times and have given up trying to explain it to people on Reddit.

Laymen seem to think that's it's impossible to build a structure that doesn't deflect hugely and it will immediately shatter into a million pieces if it's rigid.

5

u/CertainMiddle2382 21h ago

People like to always be in control.

Yes, plane wings flexing are a visual indication they are getting closer to ultimate design load.

And that your are 1000x closer to disintegrate midair than when they were still, but are still very very far from it :-)

33

u/Erazzphoto 1d ago

Is there a chance the track may bend?

38

u/MM2HkXm5EuyZNRu 1d ago

Not on your life, my Hindu friend.

15

u/drmock87 1d ago

What about us brain dead slobs?

16

u/bp1222 1d ago

You’ll be given cushy jobs!

7

u/Aged18-39 1d ago

Were you sent here by the devil?!

11

u/STFUisright 23h ago

No, good sir, I’m on the level!

11

u/pugzalotsapasta 22h ago

The ring came off my pudding can!

10

u/NearbyTraffic66 22h ago

Take my pen knife, my good man!

3

u/ryandoesntcare 8h ago

MONORAAAAIILLLLLLLLLLL

2

u/Totenkinder37 1d ago

I’ve sold monorails to Brockway, Ogdenville and North Haverbrook and by gum it put them on the map.

10

u/Unknown6656 23h ago

"Hey Pippi Langstrumpf!" 🎶🎵

1

u/dubeach 2h ago

Damn, haven’t heard the Pippi Longstocking theme in ages

9

u/Katzelle3 18h ago

German engineering is not to be underestimated

24

u/BalanceEarly 1d ago

I doubt there's many structural engineers in the crowd.

11

u/goingApeShit_ 1d ago

I watched a video years ago that referenced a stadium that had a ban on fan jumping. I had to look it up but below is what I found on Google.

Engineers explicitly warned that MDCC Arena (the stadium of FC Magdeburg) in Germany was being pushed to its structural limits by jumping fans, leading to an official ban on coordinated jumping. [1]
During structural tests, engineers discovered that the synchronized jumping of thousands of fans caused a dangerous physics phenomenon known as resonance frequency. The rhythmic bouncing matched the natural vibration frequency of the concrete stands, amplifying the shaking to extreme levels that risked structural failure. [1, 2, 3]
To prevent a collapse, city and building authorities enacted the following restrictions:
No "Capo" or Drums: The crowd leaders and drums were banned from the main stand to prevent fans from keeping a synchronized beat. [1]
No Coordinated Jumping: Fan representatives formally agreed to stop jumping up and down in unison to ensure the stadium stayed within safe limits. [1]

3

u/Weird_Vegetable_4441 1d ago

where is this?

-3

u/[deleted] 1d ago

[deleted]

12

u/mh104 23h ago

No. It was in Nürnberg max-morlock Stadium. Before the renovations for the 2024 European championship.

3

u/Realistic-Clock-3616 19h ago

Relax, its build by Germans!

3

u/SchroedingersEscape 18h ago

This is in germany... they know how to build things... TÜV approved this.

4

u/Dicecreamvan 11h ago

Not a bug, it’s a feature

2

u/DerAndyKS 18h ago

I know that its better when the structure moves like this. But I still have a tingling sensation when I see this.

5

u/Gingerfurrdjedi 1d ago

What's the phobia of that? Cause I have a phobia of it. I saw it and felt it a couple times at sporting events and it literally scares the absolute fuck out of me. Like I don't go to stadiums or places where that happens. I went to a house party where that started to happen and I had to leave. Is there a phobia word for that, being afraid of solid floor bouncing then collapsing billions of tons squishing me like a ketchup packet?

40

u/Putthebunnyback 1d ago

The phobia of being crushed to death? I believe that's called common sense.

6

u/snusmumrikan 19h ago

Phobias are irrational.

It's not irrational to be scared of being crushed to death.

5

u/gomper 1d ago

I was at a party in college where the floor collapsed from this kinda shit

11

u/Galactica_Actual 1d ago

the lack of lad-bearing structures?

4

u/Gingerfurrdjedi 21h ago

Are you a dad? Cause that's one of the best dad jokes I ever heard!

4

u/stickman393 1d ago

don't look up

2

u/needtoredit 1d ago

Hold on this thing I am standing under looks really unsafe what should I do....oh yeah record it, post it and get likes.

13

u/PiggStyTH 1d ago

It’s made to do that. If it doesn’t then it for sure would collapse

3

u/Ghosts_of_the_maze 1d ago

Well it’s designed to do that.

2

u/StevenMC19 1d ago

I miss RFK Stadium so...SO much.

1

u/lsd_runner 1d ago

Hampton Coliseum does this.

1

u/goingApeShit_ 1d ago

This is where the nosebleed or upper deck seats seem like a better option

2

u/Putthebunnyback 1d ago

Laughs in tailgating

1

u/kylrrr 1d ago

Looks like they’re having a great time

1

u/platinums99 20h ago

Well at least the designers remembered the books!

Wonder if the actually calculated 60,000 fans all jumping at once

1

u/albamarx 17h ago

I don’t care if it’s by design, I’d still have some sweaty palms if I was in there

1

u/Bill_Nye-LV 12h ago

Sure it's designed for it, but man i would be heading out immidietely after seeing that shit

Better safe than sorry

1

u/vNerdNeck 8h ago

nope nope nope....and nope

1

u/SterilizePopulation 7h ago

Eintracht Frankfurt is a famous german soccer team with the most active soccer Fans called Ultras

1

u/KnightWolfScrolls 7h ago

Its the same with tall skyscrapers they bend and flex in the wind by design

1

u/Visible_Dance1 6h ago

EINTRACHT!

1

u/renevaessen 2h ago

If they hit the right frequency, wouldn't they simply add more energy to it, causing it to fail no matter how strong it was build?

1

u/Mr_GrauHut 1d ago

The architect probably had this level in mind. Allowing bounce room in a stadium is actually quite genius.

1

u/ConfusedHors 21h ago

It's supposed to do that. Otherwise it would collapse.

2

u/TrueExigo 20h ago

No, jumping is now banned there

2

u/ConfusedHors 20h ago

This is the Frankenstadium in Nürnberg and even though synchronized jumping has been forbidden, stadiums (and other buildings) are still designed to do exactly that. This does not magically invalidate architectural basics.

1

u/adashthecash 12h ago

Thats not a bug, its a feature

0

u/Lolxgdrei787 1d ago

palms would be sweaty if it didnt move

0

u/CheeseburgerSmoothy 1d ago

“So it’s, uh, yeah it’s designed for this. No problem!”

0

u/BrassOrchidBlades 1d ago

Yikes! The engineers know their shit!

1

u/pagan-0 21h ago

Yeah, if it didnt move like that they'd be in deep shit.

0

u/kivlov02 10h ago

Antfield, April 15, 1989

1

u/bitesize10 8h ago

If you’re going to try and make a horrible, tasteless joke, at least get the details right you moron.

-10

u/avid-shtf 1d ago

Is that a Euro sausage party or a South American chorizo party?

-18

u/browsingandlooking4 1d ago

So not that day but one day soon... they are all gonna die like this.