Well There‘s Your Problem - Episode 2: Sampoong Department Store

Episode Date: November 13, 2019

Welcome to the second episode of our patented podcast-with-slides. Today @aliceavizandum, @donoteat1, and @Landerson112358 talk about the 1995 Sampoong Department Store collapse and the events leading up to it, and also talk about the Olympics. Slides located here: https://www.youtube.com/watch?v=g9SETplgPYc

So, welcome to Well Layers Your Problem, which is a podcast about engineering disasters. Yeah, we came up with a name for it now. We did come up with a name. Definitely not ripping off anyone from the blue collar comedy tour. So I'm Justin Rosniak, also known as Do Not Eat on the Internet. We're having YouTube about cities. — and doing me or today — — Alice called well Kelly or Alice Alvizandum on Twitter, if you're nasty.

I do a podcast talk called Trash Future about how technology is making everything awful and also this. — and Liam Anderson, Do Not Eats, roommate and friend — — Yes! — also on Twitter, but it's just gonna be me being a dick in Do Not Eats replied. — Yeah, I mean same. — So anyway, I got a joke. — Okay. — Go on.

— So a Catholic, a Muslim, and a Jew walk into a pod challenge. — Very good. Very good. — It's us. We're the joke. — We will be peace in our time. — Yes. — This is what interfaith dialogue is, is making fun of buildings that fall down.

— Yes. — We've done it. Where's my Nobel Peace Prize? A kiss and jerk can have one, I can have one. — All right. So today we're gonna talk about the Sampoong department store, which was built in 1987 in Seoul, South Korea. Now this building isn't there anymore.

— Off to a promising start then. — Yeah, exactly. So start out with, we're gonna talk a little bit about what this building was made of, which is a material called reinforced concrete, right? — Sounds safe. — Reinforced. Yes. Well, you know, it's reinforced, yeah.

All right. So, you know, reinforced concrete, fairly simple concept, right? We got concrete, it's got metal bars in it, right? This increases its tensile strength, because concrete's a very bad intention. It just, you know, sort of rips apart. But if you put metal in there, then you can't do that, right? And then so we have different types of bars. You might see someone say, well, we need a number three bar or a number eight bar.

The number is the diameter in eighths of an inch. — Because that's an intuitive system. — Yes. One of the very few intuitive systems in engineering, actually. And there's like a lot of complicated calculations if you're gonna figure out how these perform structurally. It depends on where you place the metal, how much it is, so on and so forth. And sometimes you get rebar that's encased in plastic.

Sometimes you don't. If you encase it in plastic, it doesn't corrode as quickly unless you get like a small gap in the plastic somewhere, in which case it corrode much, much more quickly if there were no plastic. — Hmm. Is this gonna be Chekhov's plastic rebar? — Not in this case. — Eventually, yes.

— We'll come back to this in a future episode. — Yeah, reinforced concrete does interesting things. So and then we're gonna talk a little bit about the Young's modulus and elastic and plastic deformation. This is gonna be relevant later, right? So you see this chart here. I'm sure people who are listening to this are gonna be annoyed here because the chart helps a lot.

— No, on the contrary. People in the comments last time were saying they wanted more math. They wanted you to put the math up on the corner of the screen or something. — Well, unfortunately, there's no units on this graph. So you know, you're just gonna have to deal with not having math. — Yeah, it's just it has a scale of like more to less good. — Yes. Well, there's it's interesting because some of the stuff that's good is also bad.

— It sounds like engineering. — So this is a this is a chart with stress on the vertical axis, right, and strain on a horizontal axis. Strain is the length of the piece of material over its previous length, right? So if it's like the strain is 0.01, that means it's 1% longer than it was before. And then we got this line here that goes up, it makes this a little hump, and then it makes a big hump, and then that's where the thing breaks. So when we have when we're stretching a material out, we're applying more force to it, right?

That's the stress. Well, stress is actually technically pressure, but but it's pressure in like a tension way. It's weird. So as we apply stress, we go up this straight slope here to the yield strength. This is elastic deformation, right? So when I release the pressure, it will return to its original length, right? The piece of material we're dealing with. After this point, we go into what's called plastic deformation, right?

So if we continue adding stress, it stays a longer length than it was before, right? It's bigger than before. This is generally bad from an engineering standpoint, right? But we do, we can eke a bit more strength out of the material through a process called strain hardening, right? So as as it gets longer, the molecules in the material, you know, they sort of like inner length, they get stretched out, right? So there's a little more strength you can eke out as you elongate the material to a

point called ultimate strength, right? Was that a wrestling promotion? I thought it was from an anime. Yeah. It's when you put the like rebar, it has like a gravity belt on it and then it takes that off and it achieves ultimate strength. Yes, absolutely. And then past ultimate strength, right, you can see the stress goes down as we elongate

the material. That's called necking, right? So the cross-sectional material gets smaller. So if you ever lifted like a slice of cheese pizza up, right, and there's like little strings of cheese, it's the same thing, except we're doing it with steel instead of with cheese. This is sort of a graph, which is, this graph is like representative of steel more so than it's representative of concrete, which, you know, just sort of goes up in a linear fashion and cracks.

But we're looking at reinforced concrete, right, which is a combination of steel and concrete. It does some weird stuff. Yeah. Because the steel is like deform in there, right, like the cheese in the pizza. It's like having a cheese filled crust, I guess. Basically. Yeah.

Okay. So I found a metaphor that's on my level for this. So anyway, let's get back to the building in question, right? It's a mall, right? It was not supposed to be a mall, but it became a mall. Okay. What did it start out as, or what was it supposed to be? There's this guy, Lee Joong.

He runs a company called Sampoong Group, which is mostly a construction contractor, I think. And on this site, he was going to build a four-story residential building, right? But while construction was underway, he decided, we're going to turn this into a mall. Right? Okay. So for Zoomers, a mall is where people our age used to go to shoplift, like, clip on earrings. Wander around the food court, go to the food chains, go to Hot Topic.

Yeah, I remember the days. We don't have those anymore. I think the recession took out most of them. We got lifestyle centers now, which are the same thing, but dumber and worse. No air conditioning in the house. That makes it better. Love to go to Kate Spade at a 106 degree heat, dying the whole time. So converting this to a mall resulted in some problems, right?

So this is a very sophisticated schematic of the plan of the building. This is a graph of the problems, analysis impression of the problems. Thank God you don't have a degree in art. Well, so what you're looking at is the plan view of a representation of the building, right? There's one of these dots is a column, and then there's outer walls, you know? So the plan's called for 36 inch columns. They're built to hold four stories of building, right?

As a factor of safety of two. That means that the columns are twice as strong as they need to be, right? Which is pretty good, you know? You expect like nothing bad's going to happen to this building, right? How would you double the weight of it even? Like we're going to get to that. So since Lee Jung wanted to convert this to a commercial space, a mall, he had to make some alterations to the plan, right?

So we had to carve out a couple columns so he could put some escalators in, right? Oh, of course. They made the columns narrower to fit more merchandise in the mall. The space between the columns was made larger, again, to fit more merchandise in. And along the way, there were a bunch of contractors, engineers, so on and so forth, and they told them the changes you were making are unsafe, and we're not going to do them, right? To point blank, refuse to make the changes he wanted. So what he did was he fired them and used his own in-house contractors to do it.

That's so efficient. Yes. I mean, we have to say that this is something that's absolutely inherent in South Korean culture. They have these giant corporations called chai bowls, like say Walmart or General Motors or General Electric that have vast outsize influence in their society, and that can never happen anywhere else. So you know, don't worry about this.

Absolutely not. This is impossible to happen in our sophisticated and extremely good economic system, right? So also, they decided to cheap out and use half the amount of rebar per column that was specified in the plan, so there's eight pieces of rebar instead of 16 bars, right? Now, these aren't the only changes, though, all right. So, these are actually like this isn't this isn't Justin's work. These are the original architectural plans in which they just they slap a fifth floor onto the plan.

Four floors bucket. It's done. Five floors is fine. Five and five start the same letter. Yeah. So they needed to build a fifth floor, right? Because the zoning didn't allow for a building that was strictly a mall, right? It had to be mixed use.

And you don't want to take away from your mall space, so you have to add the housing on top of it. Yeah, you got to add it. You got to add another floor. It wasn't going to be housing. It was supposed to be an ice skating rink at first, right? What kind of Trump? This guy Lee June, it just he just sounds like the porky, the capitalist pig meme, like big

top hat and everything. Didn't the company point out that the structure just wouldn't support it and they too were fired? The fifth floor? Yeah, probably. So it was converted. That space was converted while construction was underway to a couple of restaurants, right? In these restaurants had heated floors, which I guess is a it's a thing over there in it

was a it still is a thing over there in South Korea, right? And these heated floors were fourth feet thick. And that's like mostly concrete and pipes. Does he put a fucking Roman hypercorsed on top of his four story building? Yes. Yes. Ah, okay, good. That's wonderful.

So you can you can have your cauldarium and your like your baths on the top. That's where you want to have structures like that because they're known for being very lightweight. Absolutely. Definitely not adding weight by shoving in pipes in there. Definitely not. Much like swimming pools. So in addition to this, the columns on the fifth floor didn't align with the columns

on any other. Hell yeah. Yeah. So the weight of the fifth floor was entirely supported by the floor slab on the fifth floor. The load had to go like just through the column, then through the slab, then through the major column, right? I don't like the look of this already. You can sometimes get away with this.

Now when I say get away with this, that's usually not a phrase you want to use when thinking of building design. No. But that's usually when you're using a sort of construction where there's like beams holding the floor up, right? And then you'd have the column go into the beam and then the beam is big enough to transfer the load laterally. This didn't do that.

They were using flat slab construction. So there's just a floor slab, right? And then they just build the column on top of that. And this floor slab, I mean, obviously here it was very thick, but otherwise, you know, it was very thick, but for purposes of thermal conduction rather than strength, you know? So and then, of course, they also put reinforcing in the wrong spot in every floor slab, which reduced the strength. And you know, the whole thing was kind of pretty iffy, right?

Was this very iffy? Was this just to save money or was there a time thing too? Like were they hurrying to get this done? It wasn't so much to save money as to make more money in the future, right? Wei Jun is thinking for the future. He's thinking if I make this building more able to handle merchandise, then I can make more money. You know, he's he's he's thinking with the brain here, but buy more top hats and monocles.

Yes. So you know, the fifth floor, right? What is it? Just holding up the roof. So that's no big deal. Roof are usually built a little more lightly than the rest of the building because we're not putting stuff on top of the roof usually, you know, maybe you'll get some snow or some rain.

But other than that, you know, we're not really thinking in terms of like, I'm going to put a bunch of stuff on the roof, right? So you can kind of get away with this misaligned column thing on one floor, except air conditioning units. The thing that makes more as opposed to a like a lifestyle center, that's the life. Mm hmm. The sine qua non of more. So you know, it's a mall, right?

Needs a lot of air conditioning. So he had three big chillers on the roof. They weighed 15 tons each, right? Now that's not so good for, you know, a roof, which isn't designed to handle that. But as you can see in this picture, these air conditioning units, this isn't of the same building, obviously, they're sitting on steel beams, right? This is called dunnage. And the dunnage does a couple of things.

It lets you inspect the bottom of the machines more easily. It protects them from corrosion a little bit. But the main thing is you transfer the load from these very heavy chillers to places where there are columns, rather than have them just sit on the roof, which might be engineered for, you know, a much lower load than the air conditioning units are. So the Sampoong Mall, a department store, whatever you call it, had three 15 ton chillers. And I say tons weight there. A lot of times if you say tons in reference to chillers, that's in terms of tons of cooling,

which is like a weird imperial measurement, which no one quite understands. So it's like some number of BTUs. But instead of that, it's just they're extremely heavy chunks of metal. Yes. So some people in neighboring buildings complained about the noise from the chillers, right? And so Lee Cheung decides, all right, well, we'll move the chillers to get rid of these people complaining, right? So in 1993, they moved them by just dragging them across the roof.

With like teams of guys, like the beginning of Les Miserables, like I, I have no idea just pulling them with ropes or something like I have no idea. I didn't see the precise method by which they did it. Maybe they use like those Chernobyl radio controlled roof robots. Yeah. Everybody gets one minute of pulling on the air conditioner. So they just literally straight up drag these air conditioners across an already weekend roof, right?

Well, I think this guy's gonna, gonna shell out for a crane, right? So you just put them on rollers or something. That would be my guess. Yeah. That might work. The stairs or whatever. Fuck it. Yeah.

What if we just tilt the building slightly and then they'll slide down the roof to the place where we want them? Yeah. That's a good idea. Yeah. Yeah. Yes. All right.

So they moved those in 1993, right? So two years later in their new location, just sitting on the roof, there's like visible cracks in the roof slab from the air conditioners just sitting there and also powering on and powering off. That creates vibration, which makes all the, all the cracks in the roof worse, right? So Lee Jung's response is, all right, we're gonna close off that section of the star and move the, move the stuff into the basement, right? They didn't take any other action.

Because that's fine. You can have a giant hole in your roof. Like the only way that air conditioner can hurt someone is if it comes down through it and like crushes someone and turns them into mulch, right? Like, I don't know why the air conditioners had to have 150 tons on them in the Acme like white paint font in big glasses. But if they had come down through the roof, somebody could have like had a giant bump on their head and had little stars and birds floating around them and then their teeth

would have come out like piano keys. I'll see you would have opened up the door to the access hatch on the chiller and they would have stumbled out. Yeah. Just dusting themselves off. Yeah. Absolutely. Bugs, buddy, ass, building, collapse, there you do it.

So on the 29th of June, 1995, the cracks are only getting wider, right? We're starting to see plastic deformation of the roof, right? To the point where, you know, there's big enough cracks in the slab that the rebar is the only thing holding it up. So it's stretching, right? Like that's, yes. We're in a strain hardening portion. So things get a little bit better for a second, right?

For a little bit, yeah. So they close down the fifth floor in the morning, but the rest of the store is open, right? Lee Joong doesn't want to lose a day's revenue for, you know, just a hole in the roof might happen, right? Of course. Around noon, they shut off the air conditioners, turning it into a lifestyle center, as opposed to an mall.

And that was, you know, to prevent vibration from keeping, from making the cracks open further, right? They have an emergency board meeting, right? And all the board members say, look, Lee, you got to close the store. You got to get people out of here, stuff's going wrong. And Lee's like, no, I'm going to make, I'm going to make money. We've got to make money today. We'll close it down later.

We got a lot of customers today. We got to make that money. This is the attitude that really makes a businessman, because he's not just an employer, right? He's a job creator. And in a minute, he's going to create a ton of jobs in the search and rescue industry, in the funeral industry, lawyers. It's worth noting that Lee did, in fact, leave after they told him, hey, man, we got to, we got to shut it down.

But he's not stupid. He doesn't inform his own daughter, who has to be pulled out like three days later. It's his, it's his daughter in law. That's okay. That makes sense. Yeah. Yeah. Goddamn in law.

It's cold. Yeah. You have to, that's how it is in the mall business. You have to be like, look how bad I want it. You know, I'm not even taking my family out of the thing. I'm just getting out. Hashtag grind. Yeah.

Hashtag every day. Had to grind for this view. And the view is just an enormous pile of rubble, and they're pulling bodies out of it. Damn. So about 552, after, you know, all the executives have evacuated, but no one else has. That's always a bad sign, if you see all of the guys with briefcases leaving, and you're just like, yeah, I got my shift. So there's, there's audible cracking sounds throughout the building around 552 p.m.

And the workers decide, all right, we need to get everyone out of this building. Uh, well, that was a little bit too late because in 20 seconds, the whole building collapsed. Efficient. Yes. Hmm. So, you know, it just, uh, the, the air conditional fall, air conditioner falls through the ceiling. Uh, the fifth floor, the fourth floor slab can't hold that load. So it pancakes down on the third floor, pancakes down on the second floor, first floor.

And then there's three basement floors too. It got a hell of a way through there. Literally 9-eleven to his own building. Yes. Amazing. That, that's the real efficiency is you don't even need a plane to do that. You don't even need, you know, terrorists with the motivation. No, no, you can just be one guy and just be like, well, I don't really feel like closing

the thing. So. Who says capitalism can't be efficient? Yeah. How much money did he make that day? Mm-hmm. That's, that's what I want to know. Asking the real question.

All right. So this kills 502 people and traps 1,500 more people in the rebel soul's mayor immediately said, we have to call off the recue rescue operation because it's too dangerous, which, which, you know, is, is dumb. Everyone gets mad at him about that. Why, why does he do this? He thinks because the rest of the building might collapse onto the workers. Well, everyone gets mad at him.

He's like, I never said that. And they continue the rescue operation. Right. So it's, it's fake news, fake news, very bad, the lying media. After about, after about two days, they're like, okay, there's no one who's going to be alive in this building anymore, but they keep pulling out living people from the rebel until 17 days later. Jesus.

People survive just by drinking rainwater, right? And a lot of people in the lower floors survived the collapse, but then they drowned from the water used from fire suppression. Oh, well, that's cheery. I mean, this whole thing really does have something of a Trump vibe. And I like making fun of the guy because it's the only real punishment he's going to face for it. But this grim, like.

He got 10 years in prison, so it lost all his money, so at least there's that. I guess my feeling is there's, there's a general point we can derive from this, right? That, you know, Liz Warren talking about like crony capitalism or corrupt capitalism or unfettered capitalism. This is just, this is capitalism. It's working fine. Like that mole slash lifestyle center. It's working as intended until the 20 seconds before the columns punch through all of the

floor slabs. Right? Like the guy's making money. And it's not like, I made the joke earlier about it being Korean culture or whatever, but we love doing this. We love saying that engineering disasters, especially in Asia, like MH370, that's Malaysian culture of corruption or whatever, but this is what like your landlord or my landlord or any landlord would do if they could.

And there's very, very few reasons why they can't. So that's reassuring. I'm feeling very good about being on the fourth floor of a five story building right now and being like, yeah, my landlord would do this if he thought he could get away with it. That's why I like living in a hundred year old house because I figure anything that could have gone wrong already has. New construction ruins everything again. My favorite part of this is actually that there was a facility manager examining the

slabs in one of the restaurants like hours before the collapse, except that vibration from air conditioning was radiating through the cracks and the floor opened up. One of my favorite parts of the story. That is like, we can drop the title there because that really is a case of like kick the tires on the building and be like, well, it's probably fine. Yeah. Hopefully it doesn't collapse until after closing time. Yeah.

552 is pretty late. You almost made it. That was after that was after first shift. So, you know, basically closed. So now in one, but I can sort of see Lee June's logic here, right? In terms of keeping the store open, right? Because in a well engineered building, like this one, about 125 miles northwest of Seoul, which was built in the same year, which I've chosen completely arbitrarily.

Yeah, but in in a well engineered building, we don't expect failures like a roof slab failure to cascade all the way down, you know, the entire building, right? You would you would expect, you know, OK, if the roof collapses, you're going to have a big expensive hole to fix, but like, you're not going to have, you know, the whole building pancake into the basement. I detect a flaw in your logic there, which is that he built the fucking thing. He fired all of the people who told him this would happen. This is true.

And he really ate up that whole factor of safety through stupid design modifications. So, yeah, like, I'm sure it's useful at the time when he's like about to go to whatever the South Korean equivalent of club fed is, like the Orange County white collar prison system to be like, oh, I didn't know, but he did. He fired he fired all of the people who told him otherwise. Don't forget that the fire shield because they had to install the fire shield. They also had to further cut support columns. Oh, so that at least at least there was a fire.

So it's big government's intrusion into the design process, right? If they hadn't if they hadn't been burdened by the regulation of having to put in a fire shield, this might not have happened over what it's worth. The units, the air conditioning units were in fact put on rollers and just straight up dragged across the roof. I was right. Awesome. I'm disappointed by throwing down the stairs.

Logic. I'm just like an ancient Egyptian team of like slaves dragging the the chillers across the roof on logs. Yeah, more or less like. So this happened. What year did this happen? Ninety five. Yes.

Yeah, 95. That's so South Korea has been a democracy for seven years. Sort of by this point, having been propped up like a succession of US backed military dictators, you think that maybe might have had an impact on the sort of local government mechanisms for inspecting this stuff and not being paid off to not inspect this stuff? I mean, there were a lot of things falling over in South Korea in the nineties and the eighties stuff was just like, you know,

so I believe there may there may have actually been some corruption from a United States backed fascist regime. Incredibly. Well, it's worth noting that apparently in 1988. So remember that Seoul hosted the 1988 summer Olympics with that. There was a large development boom. Of course, there were bands against international construction contractors signing projects in Seoul.

So all of them were put up basically by South Korean companies who had to do it as quickly as possible because of all the projects being assigned to them. So amazing. So they want to buy domestic to show off for the Olympics, which and they just get these guys. Jesus. Just dudes. Yeah, just dudes.

Just guys being. We are I think we have to say officially episode two. We are an anti Olympics podcast. Yes. Hell yeah. Like fuck the Olympics. Fuck the IOC. Very bad.

Yeah, just horrible idea for your city or for anyone. Didn't Philly try and do an Olympics bid? We do every so often and then the mayor got real bit out of shape because everyone in Philly realized I'm goddamn stupid. It would be. Make LA do it. Atlanta had the only good Olympics because they just reused all the stuff they already had, you know.

Yeah. Yeah. So for weeks. Go ahead. Well, we in when we in London did it in 2012. We just sort of created a shadow run style like corporate state within a state that is now like constantly patrolled and like spotlights and shit in the middle of East London.

It's awesome. I wrote East London was bad. I miss bad East London. Didn't they have like dedicated lanes for Olympic Committee? Oh, yeah. Yeah. Yeah. Did they really?

Yeah. We literally had like Jiguli lanes from like the Soviet Union, but more expensive and worse. Like were they were they subject to like the congestion charge or anything like that or just of course. No, no. Why do I even ask? Well, what it's worth the building was apparently built under both regimes.

South Korea implemented democracy in 1988. But the building started to be constructed in 1987. So the top the top floor where the columns were misaligned was constructed under democracy and that's why they didn't align. Yeah. Yes. Yes. Yeah.

Yeah. That's my theory. The top floor was doing was doing grievance studies and the bottom four floors were all doing STEM. Yes. All right. So what's the lesson from this other than capitalism's bad? Yeah.

Capitalism bad. Olympics bad. Corruption bad. Corruption bad. Car bad. Train goods. Factor of safety. Good.

Factor of safety. Good. Economics bad. He said he said floors goods but ideally on ground level. Yeah. Yeah. And just don't let these just absolute motherfuckers run anything ever. Yes.

Yeah, that's that's a universal truth. Like South Korea. Please note this building is still standing. Yeah. Like it might be sort of monstrous hypocritical ambition but when it comes to a big prestige project right like it hasn't fallen down. You can say that much for it. That is a building that is still there because it's at least a sincere

ambition rather than one guy trying to get all of your money and then running 20 minutes before the columns break. All right. So does anyone have anything to pitch before we go? Listen to Trash Future, my other podcast and we have a Patreon too. You can subscribe to it. We're very funny and also very timely. We're doing a lot about MIT Media Lab at the moment which is much in the

news. It's fun. I have nothing to pitch except I guess follow me on Twitter when I inevitably become a dick in your mansion. Yes. All right. And I just watched my YouTube channel which is probably where you're watching this or you might be listening to it on some kind of podcast platform

in which case if you've been confused about what we've been talking about in terms of the building which is still standing up. There's a picture of the Ruyang Hotel in Pyongyang on the screen right now which again did not fall over. All right. So that was another that was episode two of Well Layers Your Problem and on the next episode we're going to do the Tacoma Narrows Bridge. All right.

Oh hell yeah. Awesome. Okay. Bye everyone.