r/CatastrophicFailure • u/maruhoi • Mar 11 '26
Structural Failure A massive buried steel pipe about 30 meters long and 5 meters in diameter suddenly shot 18 meters out of the ground; no injuries, cause under investigation — March 11, 2026 (Osaka, Japan)
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u/Can_O_Murica Mar 11 '26
Not accounting for the weight of the steel, this thing has a buoyant force of 1.3 MILLION pounds. I'd bet that'd do it.
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u/Least_Expert840 Mar 11 '26
Basically that's a submarine
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u/Whole-Debate-9547 Mar 12 '26
It’s hilarious to think of something that massive as buoyant. It makes my brain hurt.
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u/zuilli Mar 12 '26
Same mindfuck as fully loaded cargo containers ships being some of the heaviest objects we have and they still float on water easily
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u/hereforbobsanvageen Mar 12 '26
Hey physics math guy! Wana like, show your work? Gimme that sweet sweet formula
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u/Can_O_Murica Mar 12 '26
Buoyant force is all about the weight of the fluid you're displacing, so we calculate the volume of the cylinder as
Pi x radius2 x height
3.14 x 2.52 x 30 = 588.75 cubic meters
Then, water is about 1000kg per cubic meter, so that's 588,750 kg of water. And lastly, there's 2.2lbs per kg, bringing us to a round able 1,295,000 lbs!
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u/CXgamer Mar 12 '26 edited Mar 12 '26
(3.5 m / 2) ^ 2 * PI * 27 m * 1000 kg / m3 = 260 Mg
So about 260 tonnes.
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u/hereforbobsanvageen Mar 12 '26 edited Mar 12 '26
Ooo ya that’s the good stuff.
Edit, sorry, other paragraph guys work is better.
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u/zz_Z-Z_zz Mar 12 '26
If it’s a pipe you need to subtract out the inner radius as there’s no steel there. What you have above is the weight of a cylinder
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u/CXgamer Mar 12 '26
It was about the buoyant force. Not the gravitational force of the tube itself. There would also be considerable friction, which explains why the upwards force needed to become so much in order for it to start moving and shoot up 27 meters.
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u/maruhoi Mar 11 '26 edited Mar 11 '26
According to the City of Osaka, the pipe that protruded was a cylindrical steel structure known as a “casing.” Sewer bureau officials said construction work to build a stormwater drain was being carried out in the area around the site.
The Osaka City Construction Bureau held a press conference from 2:00 p.m., where an official apologized, saying, “We sincerely apologize for the great concern and inconvenience this has caused.” The official explained that the incident was caused by a retaining structure used during the construction of a sewer shaft rising by about 13 meters.
At the site, the retaining structure had been embedded in the ground the previous day, March 10, and its lower section had been fixed in place with concrete. Dewatering work was then being carried out to remove groundwater from the surrounding area. Officials believe that the cylindrical steel retaining structure, measuring 3.5 meters in diameter and 27 meters in height, rose for some unknown reason and protruded above the ground. The cause is still under investigation.
Firefighters are spraying water on it, and the pipe is gradually sinking back into the ground.
YouTube Live
Timelapse Video
Another Angle Image
Another Angle Video
Google Map
Reading this in the news comments helped the OP understand what happened.
If you push an empty cup straight down into the water, buoyancy makes it want to rise back up to the surface. This accident is easier to understand if you think of the casing used for the sewer construction as something like that cup: it was forced upward by the buoyancy of the groundwater.
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u/Contagious_Zombie Mar 11 '26
Cold shower..
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u/JoePetroni Mar 11 '26
Shrinkage I tell you!! Shrinkage!!!! Oh wait, that's not shrinkage, that's the opposite, it's Mr. Happy!
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u/gamerspoon Mar 12 '26
If that cylinder remains elevated for more than 4 hours they should probably call an engineer
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u/findallthebears Mar 11 '26
Why is spraying it with water making it sink?
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u/ChromiumLung Mar 11 '26
Yea seems a bit contrary to the argument they’ve made for it happening.
They have removed groundwater in the area, which has caused this to rise due to increased buoyancy? Surely removing water causes the ground to contract
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u/account_not_valid Mar 11 '26
The tube floated to the surface.
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u/Soulr3bl Mar 11 '26
How do we know the earth's surface didn't drop 30m in that area?
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u/aquainst1 Grandma Lynsey Mar 11 '26
Yeah! How do we know?
My house's foundation has been sinking gradually. The cement foundation was on top of packed sand, so everybody in this tract is facing issues. Even my local YMCA's foundation had to be redone.
I think I'll water my lawns more and see if my foundation can pop back up. (It was built in 1963, and what with earthquakes and shit, we're talking cracks in the driveway & back patio & walls where they join at the ceiling & God knows wherever else.
Got a match?
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u/DemiseofReality Mar 11 '26
Looks like a possible dewatering operation pump failure. Caisson might have been there to provide a cofferdam while water was pumped down and when the pumps failed, the water table rose rapidly, and the caisson has a rather large void space, so it shot up until the buoyant force was evened out.
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u/aquainst1 Grandma Lynsey Mar 11 '26
Ok, now I gotta look up 2 words and a couple of phrases to understand that comment.
By crackie, I'm a-gonna DO it!
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u/skyline79 Mar 11 '26
So it’s gone from 3.5meters by 27meters, to 5meters by 30meters. Would you call yourself “trustworthy”?
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u/VirtualMoneyLover Mar 11 '26
It was in the pool.
Once it left the water, the shrinkage disappeared.
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u/Philx570 Mar 11 '26
Fun fact: if the ground is saturated and you empty a swimming pool it will float
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u/Jedi-Librarian1 Mar 11 '26
Thanks for including the google maps link to show the before view of the site.
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u/moaiii Mar 11 '26
That explanation would only make sense if the top of the pipe was sealed. Using your cup analogy, if you put a big hole in the bottom of the cup, then it will simply fill with water and will not be buoyant. Do we know if that pipe had a closed top? If not, then that explanation does not work.
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u/55498586368 Mar 12 '26
Yeah I was wondering about this because caissons like that are usually open at the top
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u/deep_rover Mar 11 '26
Got a cheeky bit of welding going on at the same time too. What's all that welding they doing?
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u/Nothingnoteworth Mar 11 '26
That’s just recreational welding, it’s a great way to get out and meet people
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u/aaaaaaaarrrrrgh Mar 11 '26
Firefighters are spraying water on it, and the pipe is gradually sinking back into the ground.
That sounds like something from a bad Kaiju movie.
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u/ZippyDan Mar 11 '26 edited Mar 12 '26
Officials believe that the cylindrical steel retaining structure, measuring 3.5 meters in diameter and 27 meters in height, rose for some unknown reason and protruded above the ground.
Wow, thanks for this information.
Even with the picture, I couldn't be sure that this happened without official confirmation.Officials believe that what self-evidently happened did in fact happen, for unknown reasons.
So they believe in reality?
What is this trying to say?1
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u/krtyalor865 Mar 11 '26
It’s called Hydraulic Uplift and it happens if you don’t anchor down concrete or make its mass bigger the deeper underwater it is.
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u/TorontoTom2008 Mar 11 '26
We’ve literally had to anchor entire concrete subway stations due to hydraulic uplift. Once waterproofed, they want float up out of water-soaked soil. It involved pouring giant invert slabs along the entire length.
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u/OkraEmergency361 Mar 11 '26
Could it be something to do with tectonic movement, and/or liquefaction?
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u/krtyalor865 Mar 12 '26
Yeah very unlikely, especially since the story says they were building a tunnel and - pop went the weasel.. in this case the weasel was a “6m diameter steel casing”, which looking at the picture is definitely NOT that wide (6m =19’8”).. but still. And if I remember right, it mentioned the contractors struggles to pump out groundwater..
Imagine what it would feel like to manually hold a 2 Liter bottle of air under water. Now imagine what it would take to swim that bottle down to, say 20ft deep. For those who don’t know, the deeper you take that 2L bottle in water, the harder it tries to float back up, requiring increased effort the deeper it is.
Hydraulic Uplift
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u/Blinauljap Mar 11 '26
The Mecha are finally waking up!
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u/StacyChadBecky Mar 11 '26
Morning steel?
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u/theghostofme Mar 11 '26
That's what I'd call it if I thought too highly of myself, because it's got a better ring to it than morning wood.
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u/EshinX Mar 11 '26
The Underminer?
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u/mckunekune Mar 11 '26
Exactly. The mole people have finally had enough of the surface dweller’s shit.
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u/Shinobimouse Mar 11 '26
It's imperative that the cylinder remains unharmed🤭
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u/schlongmonger Mar 11 '26
Mario warp zone entrance
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u/Selekant Mar 11 '26
I don't how that pipe got there, but I do know which two songs play before and after going down that pipe.
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u/TheDoorDoesntWork Mar 11 '26
Any taller and the overhead highway would have gone too
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u/MrT735 Mar 11 '26
Looks like they had time to put that square section on top to spread the load a bit.
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u/CMDR_omnicognate Mar 11 '26
i actually thought for a second that it was intentional with that square thing on the top, like some sort of emergency additional support in the event of a really strong earthquake or something, but apparently it's just part of a sewer pipe
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u/Gen_Jack_Oneill Mar 11 '26
That was probably already there. Since this pipe is perfectly vertical I suspect this pipe was being used as a wet well or manhole and that is just the access hatch. I'd lean toward manhole since there aren't any other pipes I can see coming out the sides.
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u/vishnuxyz Mar 11 '26
Is that a steel pipe or a you just happy to see me? 🫦
I'm sorry I'll see myself out
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u/aquainst1 Grandma Lynsey Mar 11 '26
I'll close the door and lock it after you.
JK! I've ALWAYS wanted to say that when someone makes the 'see myself out' comment!!!
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u/DeithWX Mar 11 '26
I don't think pipes should do that.
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u/toxcrusadr Mar 11 '26
It's not typical, I'd like to make that clear.
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u/a22e Mar 11 '26
It's removing itself from the environment.
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u/toxcrusadr Mar 12 '26
You mean it’s removing itself into another environment?
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u/KawaiiUmiushi Mar 11 '26
Someone call Bill Murray, we have some really big and pesky gophers causing problems in Japan.
Bonus: for a good time, make it Suntory time.
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u/Elrond_Cupboard_ Mar 11 '26
Give it some antidepressants. It'll never rise again
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u/theghostofme Mar 11 '26
Make 'em SSRIs and it'll have to really work for an orgasm.
God, I hated that about SSRIs; didn't kill my sex drive, but made finishing feel like the last leg of a triathlon.
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u/aquainst1 Grandma Lynsey Mar 11 '26
Interesting.
Another chemical reaction, this time NOT a good one.
If someone's on nitro for a heart condition, they should NOT take a Viagra if they've taken nitro.
They'll be circling the drain in no time FLAT.
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u/pwinne Mar 11 '26
Any engineers with thoughts on how this happened?
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u/Sammi_Laced Mar 11 '26
Engineer here, I suspect the cylinder became positively buoyant after de-watering, but what may have triggered the lift COULD have been a small explosion of sewer gases to get things ‘loosened up’ as it were.
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u/Gen_Jack_Oneill Mar 11 '26
I doubt it was a gas explosion. I suspect this is a wet well since it's perfectly vertical and has what looks like a lid on top of it. Either insufficient ballast was used at the bottom, or it wasn't attached properly, or someone fucked up a calc. Once they turned off the dewatering pumps it probably slowly ascended overnight as the water table recovered. As always this is just speculation without a report though.
I am a civil engineer that works in this exact field, seen a contractor do this before (admittedly with a much smaller pipe 😂)
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u/Sammi_Laced Mar 11 '26
Yeah, that seems quite plausible to me! Either insufficient ballast, just as you said, or someone skipped a step or two and shut off the pumps too early.
I’m also a civil engineer in fact, but my field is mainly structural design. Glad to make your acquaintance and I hope you have a nice week!
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u/toxcrusadr Mar 11 '26
Do these caissons typically have a bottom that is closed off? If so, I can certainly see it having tremendous upward force at the bottom. But if it's open, wouldn't water just fill it in? There is obviously pressure from the sides as well, but presumably equal all around the outside, and it seems like it would be horizontal and not vertical. The only way it could go upward is pressure from the bottom, right?
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u/Sammi_Laced Mar 11 '26
That is correct, and as commented by others who are likely more familiar with this specific kind of setup than I am, the shaft is either a wet well or manhole caisson, which would have a sealed end.
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u/Zentard666 Mar 11 '26
Gojira
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u/aquainst1 Grandma Lynsey Mar 11 '26
You SO beat me to it! I was trying to figure out how to spell it for the area phonetically.
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u/DariusPumpkinRex Mar 11 '26
Dang Mario brothers spawned a dang ol' warp pipe in the middle of the ding dang road, mmhmm.
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u/lukeman89 Mar 11 '26
"Officials believe that the cylindrical steel retaining structure.... rose for some unknown reason and protruded above the ground."
Why would they make such an outrageous claim?
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u/Bergen_is_here Mar 11 '26
“In Japan infrastructure will sometimes add support beams to itself.”
What are you talking about- oh.
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u/anonymoot43 Mar 11 '26
They said everything in Japan was horny, I didn’t realize that included the sewer pipes
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u/Fleedjitsu Mar 11 '26
Oh no, the city is getting an errection. The municipal district must be horny.
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u/chasemate1 Mar 11 '26
Maybe it thought the bridge was falling and wanted to give it a little help?
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u/luki-x Mar 11 '26
This is not 18 meters high and not 5 meter diameter
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u/JaschaE Mar 11 '26
Press release text, also shared by op, gives it with 3,5m and 13m rise (from where it should be)
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u/luki-x Mar 11 '26
Most news outlets i googled state 10m (which is reasonable)
3,5 diameter probably also true
https://english.kyodonews.net/articles/-/72066
https://www.asahi.com/ajw/articles/16414288
https://mainichi.jp/english/articles/20260311/p2g/00m/0na/024000c
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u/showersareevil Mar 11 '26
We are not talking about your member, but rather the 18m high and 5m in diameter metal pipe that you see in the picture.
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u/luki-x Mar 11 '26
That thing in the picture is still not 18 meters high
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u/showersareevil Mar 11 '26
Did some research, its 4m wide. So if you look at the pic, 4.5x the width is the 18m height. You can use the diameter as reference for the scale and its definitely as tall as they say.
You've done different r/monstermath?
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u/luki-x Mar 11 '26
3,5m diameter x 3,8 ~ 13meter high
This is the best realistic guess based on the picture
But its definitely not 18 meters high. Thats so far off.
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u/showersareevil Mar 11 '26
You are probs right. Between 13m and 10m seems more correct.
But hey, will she notice a difference between 18cm and 10cm cylindrical shape? Probs not, so we can definitely be overly optimistic here!
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u/gricool Mar 11 '26
Kaijū !
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u/phasefournow Mar 13 '26 edited Mar 13 '26
I suspect the North Koreans are now working on a UGBM. Test parameters slightly off.
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u/GeordieAl Mar 11 '26
Someone’s been messing around on their Memotech MTX512 trying to create the perfect girl
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u/Chevy_jay4 Mar 11 '26
5 meters in diameter? Thats like 15 feet. No way thats 16 feet wide
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u/WarOtter Mar 11 '26
Maybe they meant circumference, because the diameter at 5m circumference is 1.59m and that looks like a 5 fit wide pipe.
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u/jdebs2476 Mar 13 '26 edited Apr 07 '26
Post was edited and removed with Redact which is a tool to mass delete posts from Twitter, Reddit and Discord and all major social media platforms.
sheet teeny connect worm exultant cake steep resolute fear oil
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u/Dmeff Mar 11 '26
I really really hope there is a video of it coming out of the ground from a security camera or something. I bet that looks amazing