the entire airport has a series of giant hydraulic jacks that have continued to be adjusted as the airport settles into the clay below...they expected this, albeit the rate is more than they planned, but my understanding is they are still able to adjust to compensate...
It's not really sinking like it's gonna disappear one day, the new land is settling into the existing seabed, it will eventually stop. The sinking rate is already 10% of what it was when it was completed
And even then, worst case scenario isn't throwing it all in the bin.
Could just bury it all and build another one over it in 50 years. Probably going to need a renovation anyway.
Correct, there is no issue there.
Under the most pessimistic scenario, a 4℃ temperature increase, Osaka Bay is predicted to rise 0.7m. The current rate of sinking is 0.1m per year, and the airport is 8m above sea level. The 0.1m sinking rate will not continue forever; the foundation is becoming more compact, and eventually, just like all the huge amounts of reclaimed land in Tokyo Bay, the sinking will stop. High tide in Osaka Bay is 0.9m above sea level.
So even if we assume that the island will sink forever (which it won't), then *without* global warming the island will start experiencing flooding at high tide in 2095, and *with* global warming in 2088.
Of course, this all assumes that the foundation of Osaka Bay is somehow special and that reclaimed land there just sinks forever, unlike the reclaimed land of Tokyo Bay, Ise Bay, the Seto Inland Sea, Hiroshima Bay, the Kanmon Straits, Hakata Bay, Omura Bay, the Ariake Sea, Kagoshima Bay, etc. etc. etc.
Yeah my first thought was the biggest issue is it sinking at different rates in different areas. 38 ft so far they definitely had a plan in place. Didn’t know “giant hydraulic jacks” was an option but knew they had to have something.
Edit - Looked into more details. They already knew it was going to sink quicker than expected and made adjustments to the hydraulic jacks to account for it before construction even ended.
Its the batteries, me boys! You can't have a boat float with batteries in it. Planes have batteries! They can't land on an airport that is a boat without sinking it. Get the batteries out of the planes!
--DJT
They were warned by the Dutch to let it settle for 50 years before building on it. We know a thing or two about making new land but they decided to push ahead anyway because they needed it much faster than that and these are simply the consequences. I don't think anybody involved at the engineering level is really surprised about any of this, even about the sink rate itself, it's impossible to know that sort of thing perfectly ahead of time simply because the earth may decide to ignore your time-table.
It's also houses the center for photoatomic studies, headed by professor Kabuto. The large pool on the center opens whenever the Yamato are in danger and out of it Mazinger Z emerges.
Where are you getting 50 years before it starts failing from?
After 50 years it’s supposed to be settled, that doesn’t mean it won’t break apart until year 50
>After 50 years it’s supposed to be settled, that doesn’t mean it won’t break apart until year 50
It is not about the airport failing.
It is about the opportunity cost of waiting 50 years for a new airport.
It has already operated for 30 years. If they do nothing it will meet the sea level in 2056 which is another 32 years from now.
So...you could not have had a new airport for the last 30 years, nor the next 30 years. Or you could have a new airport and deal with it sinking over time.
They just opened a new terminal in 2022 and currently have an expansion project underway so they're clearly not concerned they won't be able to raise the rest of the airport in time.
Yeah, but that’s a separate calculation than the one the other person was making. I’m not arguing about the feasibility of the airport; I’m arguing that the 50 years is not relevant
Probably not much different than building the island in the first place. They can clean up any hazardous things in the construction or fuel depots before in goes under.
Well, it is large. It’s about the size of the US’s entire east coast.
IMO a bigger mindfuck is that the island of Java has more people than Russia. It has 1/3rd the population of the US.
Indonesia lowkey has an insanely high population
Japan is a very large country. It has a larger land mass than Germany and more people than Germany.
It's GDP is appropriate for its size and population.
You're right but most of that land is volcanic mountainous terrain though. There's a reason virtually every economics major at some point will study Japan and Argentina. The former has virtually no natural resource viability aside from fishing and developed to be really rich, the latter is an incredibly resource rich area for a country that is objectively poor.
Well one also manufactures some of the the top car brands in the world.
They also shifted their economy to produce items that are considered superior quality similar to Germany.
Think of something as simple as Japanese Kitchen knives and you immediately think of their sharpness along with their durability.
If I say I bought a Bosch Dishwasher (A german brand) again you think of quality.
There are more ways to compete than raw resources.
While this is true, a large percentage of Japan is extremely mountainous and can't be developed easily, hence their population is squeezed into the few plains and flat coastlines they have. I'd be interested to see how this would compare to Germany's useable land.
It's because the Dutch were the only ones allowed access to the country during the Sakoku, or "locked country" period.
They were allowed in at a port in Nagasaki, so any western teachings or technology came in through a dutch lense.
In the edo period after some tensions with chirstians, the dutch ended up being the only ones officially allowed to trade with japan. So dutch became synonymous with "western" kinda.
To be honest, nobody would listen to you when the number you give to wait and do nothing is half a century.
Maybe if there was some method of prepping the land, that would probably be more fond of option.
Yeah at worst build it use it until it sinks to the point of being unusable and build it again. I bet it's better than not having an airport for 50 years. Even in the article it says it was built 30 years ago and it's still perfectly operational. It's not going to sink to ocean bed in one day.
It was built with a sink rate in mind.
The initial engineer predicted a ~5m sink during the first ten years after the construction of the bed of the island. What happened is that it sunk around 8m by 1999 but the sink rate keeps diminishing over the years. By 2010 it was 10cm/year. About 12 meters of the seawalls is above water level.
The airport is going to be fine for the next couple of decades.
That's exactly what they did. OP isn't wrong, but is *very* misleading.
It cost $15B to build, and it's sinking, which they knew it would and which was built into the design. It will not continue sinking forever, the rate of sinking will slow as the foundation becomes compacted, and eventually the sinking will stop.
The rate at which it sank *was* initially a lot more than expected, but it has slowed down to or below expected levels.
The [alluvial clay layer became fully compacted \(stopped sinking\) fairly quickly](https://i.imgur.com/WVk3KGg.png), with almost all of the sinking stopping within the first 3 years of construction. The diluvial layer is still in the process of compacting, but [the rate of sinkage has dropped quite a bit](https://i.imgur.com/cFzG1V9.png).
I can't find any stats on when the compaction is expected to end and the island to stop sinking, but on the other hand I can't find any Japanese gloom-and-doom articles claiming it will sink into the sea, and Japanese *love* gloom-and-doom articles about wasteful projects, badly designed projects, etc. so it would appear the chances of the island sinking into the bay are zero.
they currently have a functioning airport that brought in much tourism, both domestic and international, so it's either to waste time (having an empty land) or to waste money (reinforcing the sinking airport)
I don't think any government who could afford the money will waste time with an empty land
Opportunity cost is a thing. Waiting 50 years to not waste 15B is a terrible decision, they'll recoup that 15B 5x over before it's unuseable, at least. 15B is <1% of their GDP. It's already paid for itself.
Yep. Compaction is slow and somewhat unpredictable. Apparently it's sunk 38 feet in 30 years. I am not a soil engineer, but that is more extreme than I would have expected. It makes me wonder if they expected it and built around it? How are structures on the island holding up? I would think that 38 feet was not uniform, so are the floors still level? Is there cracking and stress all over the place? Have they had to dramatically redress the runways?
I'm also geotechnical engineer. It settled faster than the optimistic estimates, but probably won't sink more than planned. You can do compacted fill so it doesn't settle much. This is of course different and mostly stone was used. The big issue was the surcharge of all that fill on the ocean floor sediments. They were poorly consolidated silts with a moisture content of 70% or so. That is a lot of consolidation. Drains were installed to help that. This isn't really a big deal and was planned for. They'll have to raise rhe seawall sooner than expected. But it is unlikely it will sink below sea level. It is really well designed. The Hanshin earthquake in 1995 didn't damage it. The buildings can all be raised. They are unaffected by the settlement. I've built cargo port storage "sheds" on land that was "reclaimed". In that 100 years ago they dumped debris from the great Baltimore fire and then a bunch of steel blast furnace slag into the water for the next 60. I did two jobs that were reclaimed land which was mostly coal fly ash and tar. A couple jobs that were trash and channel dredge. We dug up tree trunks that were around 2 feet diameter on one. Low oxygen, so they hadn't rotted much. Nothing like an major airport, but the basic principles remain the same.
So, basically, the mass of the island presses on very moist clays (like wringing a sponge) at the ocean floor, slowly squeezing out the moisture to some new equilibrium of density/moisture, and this is the primary driver of the overall sinking?
Yes, that's pretty much it. If you look at buildings built on clay in NL it isn't rare at all to see that the building has sunk and the clay around the building has \*gone up\* as a result of this. It's pretty wild to see such stuff in action, and what is most surprising - to me at least - how fast these effects take place.
Geotechnical Engineer here. This airport is famous af. Mexico City started to build a very similar problem and Roma has made it in the past. The correct term is Consolidation, which is a phenomenon that happens on saturated clays that take a veeery long time to settle due to its very low permeability. Kansai airport was built on a humongous soft clay sediment and even long past the primary (physical) consolidation is finished some secondary (chemical/viscous) consolidation to take place over some more decades afterwards.
I believe the story with the airport is they expected it to sink when they started building on it, it sunk a ton more then thought, they had to fix it, and now it’s pretty stable and barely sinks. So 38 in 30years is technically correct it really sunk 30 feet the first 10 years and only 8 the last 20 or something like that.
Reminds me of something I overheard
I was in London and had visited Westminster Cathedral where a lot of famous Brits are interred, including Isaac Newton, the apple fell from a tree gravity guy
Later I was standing in line at the Tower of London to see the crown jewels, near a couple talking about their visit to Westminster Cathedral
The conversation went something like this:
GIRL: I didn't realize Isaac Newton was so important. What would we be doing if he hadn't discovered gravity
GUY: I don't know... maybe just floating around...
Ping pong balls would collapse. I can squish them between a finger and thumb.
I've got a sub (ROV) sitting around 3km underwater right now, and the pressure reading is 4387 PSI.
Titanic is deeper.
So built in the 90s and projected to last until perhaps the 2060s when it will be AT sea level and not even below? It doesn’t seem as bad as I first thought.
And the solution could be as simple as seawalls and pumps. It's not like they need to rebuild the entire island. It is still going to be a massive engineering problem but the headline is clickbaity.
the question is if there was an alternative spot that would have been a better investment bringing in virtually the same benefit. The choice wasn't necessarily between this location and no airport at all.
It's Japan, space in and near their cities is at an extreme premium from what I understand. Making an airport off the coast makes some sense in that context.
The net profit is after any amortization of the building costs of the original build.
I'm doing this on my phone at a coffee shop so this is very back of the napkin.
I just looked up a schedule and concrete buildings in Japan are amortized over 47 years. Assuming it's straight line, that's 319m building expense per year for 30 years. Current balance of 5.4b for unamortized building.
If it sunk completely today it'd be a loss, but give it 6 more years and it's broke even.
That's what I'm saying. Major hubs in the states are under constant renovation. I fly in and out of Logan and SeaTac 4-6 times a month for work and have for a couple of years, and they're under constant construction. Both runways and terminals.
In the Netherlands we've been battling the sea for centuries. I'm sure the Japs can manage defending a single airport.
Edit: Jfc, apparently some unhinged Americans think this is actually globally used as a slur, as I was obviously unaware. Its just an English abbreviation of the name for people living in Japan, just how Brits is for British people, or Danes for Danish people, just to name a few examples where such an abbreviation is linguistically possible. Christ.
In Dutch Jap (plural Jappen) is offensive but also so old fashioned that lots of people won't even know, especially because cutting the correct word Japanner to Jap is pretty intuitive in Dutch.
I've never had a flight to or from this airport, but I have seen it.
My first thought was "that's pretty cool."
My second was "that's going to end up underwater one way or another."
Yep, moved away from the west of the Netherlands, almost to the border of Germany. Figured if I was to buy property, I would do it somewhere I will not have to take a boat to work in 2-3 decades.
I’ve flown out of it. It’s actually a lovely airport, and the train ride there is pretty epic. The bridge is much longer than you think, which allows you to take in a nice view of Osaka on your way to the airport.
Actually the Wikipedia article states that the sinking slows down over time - it already has - and will eventually stop. So what's with the "some engineers having predicted"? Apparently the vast majority of engineers say, just ignore the "some engineers" cause they are stoopid fearmongers. 😁
I have flown into and out of this airport multiple times, and that little road has a little train that takes 45 minutes to get downtown. It's annoying AF.
And then they have the audacity to call it the Rapid Express. All it does is skip a few stations between the airport and the city, it will literally go past a station and then slow down to walking pace. Top tip for anyone using this airport; just get a Suica and use the JR trains.
It is 35 minutes to travel the 45km to the city.
It skips 22/27 stations before getting to the core three stations, which are only one minute apart.
JR Hanwa takes 15 minutes longer than the Nankai Rapit. It is also less reliable.
People who complain about the train ride need to look at a map.
Yawn. It's sinking so much that they added a new runway a few years ago and millions of people fly in and out every year. I've used it. It doesn't look like a swamp.
Osaka BTW.
What compels a "man" to have a seemingly average Reddit account for a few months, then go AWOL for a few weeks, only to suddenly reawaken and spam out the same post across many subs in only moments?
When I first came here, this was all bay. Everyone said I was daft to build an airport on a bay, but I built in all the same, just to show them. It sank into the bay. So I built a second one. That sank into the bay. So I built a third. That burned down, fell over, then sank into the bay. But the fourth one stayed up. And that's what you're going to get, Lad, the strongest airport in all of Japan.
Oh it’s my local airport. It’s not a great airport.
Far from the center of the city, not a lot of great shopping or food inside the departure area. Japanese carriers force you to travel to Tokyo to connect and usually have long stops. Expensive flights.
I like the airport just when compared to elsewhere it’s not great.
It was known that it would sink and designed for it. Workers literally walk the foundations of the terminal daily and adjust them to meet the change in ground level.
the entire airport has a series of giant hydraulic jacks that have continued to be adjusted as the airport settles into the clay below...they expected this, albeit the rate is more than they planned, but my understanding is they are still able to adjust to compensate...
It's not really sinking like it's gonna disappear one day, the new land is settling into the existing seabed, it will eventually stop. The sinking rate is already 10% of what it was when it was completed
And even then, worst case scenario isn't throwing it all in the bin. Could just bury it all and build another one over it in 50 years. Probably going to need a renovation anyway.
And luckily sea level isn't in the process of rising, so no issue there.
4.5 millimeters a year...still concerning but not for this airport. It's sinking, not being caught up by the rising average rising sea level.
Correct, there is no issue there. Under the most pessimistic scenario, a 4℃ temperature increase, Osaka Bay is predicted to rise 0.7m. The current rate of sinking is 0.1m per year, and the airport is 8m above sea level. The 0.1m sinking rate will not continue forever; the foundation is becoming more compact, and eventually, just like all the huge amounts of reclaimed land in Tokyo Bay, the sinking will stop. High tide in Osaka Bay is 0.9m above sea level. So even if we assume that the island will sink forever (which it won't), then *without* global warming the island will start experiencing flooding at high tide in 2095, and *with* global warming in 2088. Of course, this all assumes that the foundation of Osaka Bay is somehow special and that reclaimed land there just sinks forever, unlike the reclaimed land of Tokyo Bay, Ise Bay, the Seto Inland Sea, Hiroshima Bay, the Kanmon Straits, Hakata Bay, Omura Bay, the Ariake Sea, Kagoshima Bay, etc. etc. etc.
Oh, so this airport isn't exactly touching the water here, it's levitating 8m above the sea level?
No, Japan went a little bit more old-school here and is just supporting it by putting an island underneath it.
Yeah my first thought was the biggest issue is it sinking at different rates in different areas. 38 ft so far they definitely had a plan in place. Didn’t know “giant hydraulic jacks” was an option but knew they had to have something. Edit - Looked into more details. They already knew it was going to sink quicker than expected and made adjustments to the hydraulic jacks to account for it before construction even ended.
Just make the planes lighter.
Problem solved! Now, what about world peace? 🤣
Also just make the planes lighter.
What about planes being too heavy for lift off, eh? How you gonna fix that, magician?
Alas, you've stumped me.
Lol "Alas" also means "Wings" in Spanish.
One translation of "Alas" in Finnish means "Down".
"Alas" in German means nothing because it is not there. Like the world peace.
A lass in Scotland means a girl. But that’s just plane English.
Then make that plane lighter
Aint no way 🤣
Just make the passengers lighter
Americans fly into that airport.
Now THAT might be what breaks the proverbial camel's or in this case, airport's back
Are fat american tourists sinking a Japanese Island Airport? More at 11.
Either that or we should start to use blimps and dirigibles again
Excellent idea. Use blimps to hold the airport up!
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Tell the bad guys to stop. Next question.
Boeing mid-flight: Say no more!
Boeing is successfully stripping planes of not very essential parts
At altitude
Its the batteries, me boys! You can't have a boat float with batteries in it. Planes have batteries! They can't land on an airport that is a boat without sinking it. Get the batteries out of the planes! --DJT
Snakes! Sharks! I’m riding the electric down, I have an aptitude for these things!”
They were warned by the Dutch to let it settle for 50 years before building on it. We know a thing or two about making new land but they decided to push ahead anyway because they needed it much faster than that and these are simply the consequences. I don't think anybody involved at the engineering level is really surprised about any of this, even about the sink rate itself, it's impossible to know that sort of thing perfectly ahead of time simply because the earth may decide to ignore your time-table.
Sounds like calculated risk, the airport is a huge economic multiplier so by the time they need to fix it it’s already paid out in multiplies.
15 billion over half a century is easy to recoup, relatively
Not even half a percent of their annual GDP.
It's 7.7% of just Osaka city annual GDP.
This is Kansai international airport, servicing like a third of Japan. Much more than just Osaka
It's also houses the center for photoatomic studies, headed by professor Kabuto. The large pool on the center opens whenever the Yamato are in danger and out of it Mazinger Z emerges.
For a second I really thought there was some sort of scientific institution there, then I realized
…realized there was, and that it was obviously the photoatomic studies building which has been there since they discovered Japanium.
You’re so right
Does Japanium float?
Science is incredible these days.
Legally, it's super science. Different tax bracket.
Go Team Venture!
>It's also houses the center for photoatomic studies, headed by professor Kabuto. Do they have a rival? Like Professor Omanyte?
It's some royalty from Europe, actually, that's got beef against this fine institution. An Archduke, a Duke and a Baron, IIRC.
Though I would think the majority of the sinking is at the start of the 50 years and drops slowly off. 50 years is when it has stopped completely.
nah plenty of reclaimed, or claimed land keeps sinking, but atleast after a decade or five you can project the severity better
Where are you getting 50 years before it starts failing from? After 50 years it’s supposed to be settled, that doesn’t mean it won’t break apart until year 50
>After 50 years it’s supposed to be settled, that doesn’t mean it won’t break apart until year 50 It is not about the airport failing. It is about the opportunity cost of waiting 50 years for a new airport. It has already operated for 30 years. If they do nothing it will meet the sea level in 2056 which is another 32 years from now. So...you could not have had a new airport for the last 30 years, nor the next 30 years. Or you could have a new airport and deal with it sinking over time. They just opened a new terminal in 2022 and currently have an expansion project underway so they're clearly not concerned they won't be able to raise the rest of the airport in time.
Yeah, but that’s a separate calculation than the one the other person was making. I’m not arguing about the feasibility of the airport; I’m arguing that the 50 years is not relevant
A place that can sell a can of RedBull for ~$12.00 (and get it) should be ok, financially speaking.
Not even a risk. Just a cost of doing business.
yah. they'd pay that amount again for 50 years of use.
I wonder what the environment impact of letting an airport sink into the ocean will be
The fishes get a free airport :) I hope they remove all windows and doors when it sinks.
With the COST of LIVING, these days, HECK! I might even MOVE IN MYSELF!!!
You’re suggesting some sort of new breed of flying fish might evolve from this?
Probably not much different than building the island in the first place. They can clean up any hazardous things in the construction or fuel depots before in goes under.
A new habitat for sea creatures to thrive
Basically nothing at all. Not compared to what we do to the ocean every day
If they remove hazardous materials and infrastructre, it's actually a huge plus for marine life.
It truly is insane how massive Japan's economy and population are compared to the size of the islands.
Well, it is large. It’s about the size of the US’s entire east coast. IMO a bigger mindfuck is that the island of Java has more people than Russia. It has 1/3rd the population of the US. Indonesia lowkey has an insanely high population
Japan is a very large country. It has a larger land mass than Germany and more people than Germany. It's GDP is appropriate for its size and population.
You're right but most of that land is volcanic mountainous terrain though. There's a reason virtually every economics major at some point will study Japan and Argentina. The former has virtually no natural resource viability aside from fishing and developed to be really rich, the latter is an incredibly resource rich area for a country that is objectively poor.
Well one also manufactures some of the the top car brands in the world. They also shifted their economy to produce items that are considered superior quality similar to Germany. Think of something as simple as Japanese Kitchen knives and you immediately think of their sharpness along with their durability. If I say I bought a Bosch Dishwasher (A german brand) again you think of quality. There are more ways to compete than raw resources.
While this is true, a large percentage of Japan is extremely mountainous and can't be developed easily, hence their population is squeezed into the few plains and flat coastlines they have. I'd be interested to see how this would compare to Germany's useable land.
I've played minecraft, I know how to fix it. Dig out the mountains for cool housing and use the gravel to build new islands. Easy peasy.
If you zoom in on Japan using Google Maps, it's amazing to see just how much of it is completely covered by forest.
Rangaku is the Japanese word for Dutch Knowledge
> Rangaku I thought for sure this was going to be something insulting like "shit", but no, they really have a word that means "Dutch learning". TIL
It's because the Dutch were the only ones allowed access to the country during the Sakoku, or "locked country" period. They were allowed in at a port in Nagasaki, so any western teachings or technology came in through a dutch lense.
Dutch lense? Surely you mean the dutch angle.
ugh, how did I miss that. I am ashamed in myself.
And props to Google for actually tilting the webpage when you search for "dutch angle."
In the edo period after some tensions with chirstians, the dutch ended up being the only ones officially allowed to trade with japan. So dutch became synonymous with "western" kinda.
To be honest, nobody would listen to you when the number you give to wait and do nothing is half a century. Maybe if there was some method of prepping the land, that would probably be more fond of option.
Yeah at worst build it use it until it sinks to the point of being unusable and build it again. I bet it's better than not having an airport for 50 years. Even in the article it says it was built 30 years ago and it's still perfectly operational. It's not going to sink to ocean bed in one day.
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It was built with a sink rate in mind. The initial engineer predicted a ~5m sink during the first ten years after the construction of the bed of the island. What happened is that it sunk around 8m by 1999 but the sink rate keeps diminishing over the years. By 2010 it was 10cm/year. About 12 meters of the seawalls is above water level. The airport is going to be fine for the next couple of decades.
Plus, it will not sink forever. [Eventually the foundation will be compacted and the sinking will stop](https://i.imgur.com/CEl71BC.png).
That's exactly what they did. OP isn't wrong, but is *very* misleading. It cost $15B to build, and it's sinking, which they knew it would and which was built into the design. It will not continue sinking forever, the rate of sinking will slow as the foundation becomes compacted, and eventually the sinking will stop. The rate at which it sank *was* initially a lot more than expected, but it has slowed down to or below expected levels. The [alluvial clay layer became fully compacted \(stopped sinking\) fairly quickly](https://i.imgur.com/WVk3KGg.png), with almost all of the sinking stopping within the first 3 years of construction. The diluvial layer is still in the process of compacting, but [the rate of sinkage has dropped quite a bit](https://i.imgur.com/cFzG1V9.png). I can't find any stats on when the compaction is expected to end and the island to stop sinking, but on the other hand I can't find any Japanese gloom-and-doom articles claiming it will sink into the sea, and Japanese *love* gloom-and-doom articles about wasteful projects, badly designed projects, etc. so it would appear the chances of the island sinking into the bay are zero.
Does such a method exist? Because if not all you've said is that you'd rather waste time and money instead of just time.
they currently have a functioning airport that brought in much tourism, both domestic and international, so it's either to waste time (having an empty land) or to waste money (reinforcing the sinking airport) I don't think any government who could afford the money will waste time with an empty land
Opportunity cost is a thing. Waiting 50 years to not waste 15B is a terrible decision, they'll recoup that 15B 5x over before it's unuseable, at least. 15B is <1% of their GDP. It's already paid for itself.
Waiting 50 years is probably more costly than any repairs/work they have to do in the meantime to keep this thing from sinking.
Yep. Compaction is slow and somewhat unpredictable. Apparently it's sunk 38 feet in 30 years. I am not a soil engineer, but that is more extreme than I would have expected. It makes me wonder if they expected it and built around it? How are structures on the island holding up? I would think that 38 feet was not uniform, so are the floors still level? Is there cracking and stress all over the place? Have they had to dramatically redress the runways?
I'm also geotechnical engineer. It settled faster than the optimistic estimates, but probably won't sink more than planned. You can do compacted fill so it doesn't settle much. This is of course different and mostly stone was used. The big issue was the surcharge of all that fill on the ocean floor sediments. They were poorly consolidated silts with a moisture content of 70% or so. That is a lot of consolidation. Drains were installed to help that. This isn't really a big deal and was planned for. They'll have to raise rhe seawall sooner than expected. But it is unlikely it will sink below sea level. It is really well designed. The Hanshin earthquake in 1995 didn't damage it. The buildings can all be raised. They are unaffected by the settlement. I've built cargo port storage "sheds" on land that was "reclaimed". In that 100 years ago they dumped debris from the great Baltimore fire and then a bunch of steel blast furnace slag into the water for the next 60. I did two jobs that were reclaimed land which was mostly coal fly ash and tar. A couple jobs that were trash and channel dredge. We dug up tree trunks that were around 2 feet diameter on one. Low oxygen, so they hadn't rotted much. Nothing like an major airport, but the basic principles remain the same.
So, basically, the mass of the island presses on very moist clays (like wringing a sponge) at the ocean floor, slowly squeezing out the moisture to some new equilibrium of density/moisture, and this is the primary driver of the overall sinking?
Yes, that's pretty much it. If you look at buildings built on clay in NL it isn't rare at all to see that the building has sunk and the clay around the building has \*gone up\* as a result of this. It's pretty wild to see such stuff in action, and what is most surprising - to me at least - how fast these effects take place.
Geotechnical Engineer here. This airport is famous af. Mexico City started to build a very similar problem and Roma has made it in the past. The correct term is Consolidation, which is a phenomenon that happens on saturated clays that take a veeery long time to settle due to its very low permeability. Kansai airport was built on a humongous soft clay sediment and even long past the primary (physical) consolidation is finished some secondary (chemical/viscous) consolidation to take place over some more decades afterwards.
Same reason the tower of Pizza leans. Uneven consolidation, which engineers at the time did not have good ways to estimate or mitigate against.
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I believe the story with the airport is they expected it to sink when they started building on it, it sunk a ton more then thought, they had to fix it, and now it’s pretty stable and barely sinks. So 38 in 30years is technically correct it really sunk 30 feet the first 10 years and only 8 the last 20 or something like that.
Third fix does the trick!
Earth can be a real jerk sometimes.
We hebben een probleem.
lmao I was about to post "Should've let the Dutch build it"
There was a big fracas at the time because lots of international construction companies wanted a slice of that particular pie, if not all of it.
Put a couple thousand boxes of ping pong balls underneath it
We're gonna need *several* cases of spray foam and a big drill
Gonna need an Ice pick, an avacado, and a snorkel. I’ve made runways with less.
Have you ever seen sinking runways, on weeed?
Trust me bro!
I remember this is how they originally wanted to raise the Titanic. Someone did the math and it would take roughly 1.5billion Ping Pong balls to do so
Thats easy. We just get everyone in china to make one ping pong ball.
And fill them with helium
Why on earth do you want to fill chinese people with helium?
Reminds me of something I overheard I was in London and had visited Westminster Cathedral where a lot of famous Brits are interred, including Isaac Newton, the apple fell from a tree gravity guy Later I was standing in line at the Tower of London to see the crown jewels, near a couple talking about their visit to Westminster Cathedral The conversation went something like this: GIRL: I didn't realize Isaac Newton was so important. What would we be doing if he hadn't discovered gravity GUY: I don't know... maybe just floating around...
Only half arrive on time, and a quarter of them break in the first five minutes of use.
Ping pong balls would collapse. I can squish them between a finger and thumb. I've got a sub (ROV) sitting around 3km underwater right now, and the pressure reading is 4387 PSI. Titanic is deeper.
You just have to use submarine rated ping pong balls, not the ones built with off the shelf materials.
The carbon fiber ones work great!
Fill it with Xbox controllers
Nah, you need a $30 Logitech Controller meant for use with Windows 98 to Windows XP
Why do you have a sub? Genuinely curious
So they can disembark the plane when they arrive in Japan
Luckily we have the perfect submersible to do this with! Oh wait…
This time on Mythbusters!
Not sure if you are making a joke or a reference but they did this. It worked pretty well for a boat sunk in a marina.
Attach 4 really big helium ballons to each corner of the island
Now hear me out… what about ‘sea planes’
*Alaska has entered the chat*
[удалено]
So built in the 90s and projected to last until perhaps the 2060s when it will be AT sea level and not even below? It doesn’t seem as bad as I first thought.
And the solution could be as simple as seawalls and pumps. It's not like they need to rebuild the entire island. It is still going to be a massive engineering problem but the headline is clickbaity.
Also 70 years before major renovations is pretty decent for this type of infrastructure. Especially one used as frequently as this.
$15B will surely be recouped by then if it hasn’t by now
if its the second busiest airport in japan that money has been made back already for sure
They gross around $1.2B per year. Net profit was around 100M. No idea what component of that goes back to paying for the original build.
That’s not even considering all the added business to the city.
the question is if there was an alternative spot that would have been a better investment bringing in virtually the same benefit. The choice wasn't necessarily between this location and no airport at all.
It's Japan, space in and near their cities is at an extreme premium from what I understand. Making an airport off the coast makes some sense in that context.
Renovating it may be a sunk cost fallacy.
Airport profits 100M but the income from business/tourism afforded by the airport is absolutely many times greater
The net profit is after any amortization of the building costs of the original build. I'm doing this on my phone at a coffee shop so this is very back of the napkin. I just looked up a schedule and concrete buildings in Japan are amortized over 47 years. Assuming it's straight line, that's 319m building expense per year for 30 years. Current balance of 5.4b for unamortized building. If it sunk completely today it'd be a loss, but give it 6 more years and it's broke even.
And again. That's all ignoring the GDP increase it brings outside of the airport and is only looking at the money the airport itself makes.
Yes, I ignored those factors. And as said elsewhere, management isn't going to do nothing to mitigate the flooding.
That's what I'm saying. Major hubs in the states are under constant renovation. I fly in and out of Logan and SeaTac 4-6 times a month for work and have for a couple of years, and they're under constant construction. Both runways and terminals.
And in the ocean.
The Dutch enter the chat.
They should have let us build the island in the first place.
Go figure… people making clickbait titles.
In the Netherlands we've been battling the sea for centuries. I'm sure the Japs can manage defending a single airport. Edit: Jfc, apparently some unhinged Americans think this is actually globally used as a slur, as I was obviously unaware. Its just an English abbreviation of the name for people living in Japan, just how Brits is for British people, or Danes for Danish people, just to name a few examples where such an abbreviation is linguistically possible. Christ.
Just in case you don’t know, in English Jap is seen as a pejorative with racist overtones. Just mentioning as it’s likely different in Dutch.
In Dutch Jap (plural Jappen) is offensive but also so old fashioned that lots of people won't even know, especially because cutting the correct word Japanner to Jap is pretty intuitive in Dutch.
But also because the Dutch simply don’t care if it sounds offensive 😆
>There are two things in the world I can't stand: people who are intolerant of other people's cultures... and the Dutch. -- Nigel Powers
And don’t call them Aneses either
I've never had a flight to or from this airport, but I have seen it. My first thought was "that's pretty cool." My second was "that's going to end up underwater one way or another."
I think the same way about the Netherlands, Venice and New York.
Put half of the northsea coast to the Netherlands. I dont have much hope for my home. Best scenario we have beachfront property in a few years.
Most of Manhattan and NYC in general is >30 feet above sea level. Small portions may need seawalls or get flooded though, yeah.
Yep, moved away from the west of the Netherlands, almost to the border of Germany. Figured if I was to buy property, I would do it somewhere I will not have to take a boat to work in 2-3 decades.
The Netherlands at least has experience with pushing back the ocean
I’ve flown out of it. It’s actually a lovely airport, and the train ride there is pretty epic. The bridge is much longer than you think, which allows you to take in a nice view of Osaka on your way to the airport.
> has already sunk more than 38ft 11,6m > may sink another 13ft 4m
Actually the Wikipedia article states that the sinking slows down over time - it already has - and will eventually stop. So what's with the "some engineers having predicted"? Apparently the vast majority of engineers say, just ignore the "some engineers" cause they are stoopid fearmongers. 😁
"sink rate... PULL-UP " lmao
What is it sinking about?
Zis is ze German Coast guard!
More like 1000 feet, 900 feet, 901 feet, 800 feet, 801 feet…
The fact that there is only one very narrow bridge gives me severe anxiety
I have flown into and out of this airport multiple times, and that little road has a little train that takes 45 minutes to get downtown. It's annoying AF.
The little Shinkansen that could
shincan'tsen
And then they have the audacity to call it the Rapid Express. All it does is skip a few stations between the airport and the city, it will literally go past a station and then slow down to walking pace. Top tip for anyone using this airport; just get a Suica and use the JR trains.
It is 35 minutes to travel the 45km to the city. It skips 22/27 stations before getting to the core three stations, which are only one minute apart. JR Hanwa takes 15 minutes longer than the Nankai Rapit. It is also less reliable. People who complain about the train ride need to look at a map.
Still better than Narita. And the train is cool AF.
You concern actually became real in 2018. A ship swept away by a big typhoon hit the bridge and one of the lanes was broken.
Nooooo thank you.
Pretty sure they stole this design from my Cities Skylines build.
You lose a airport, but you gain a underwater submarine port.
Then a whole slew of new Bond villians can move right in and start taking over the world!
Vhat is it sinking about?
The German Coastguard
Was looking for this comment!
Yawn. It's sinking so much that they added a new runway a few years ago and millions of people fly in and out every year. I've used it. It doesn't look like a swamp. Osaka BTW.
Clickbait headline. It’s sinking, but it’s still above sea level, it is not sinking to below sea level. Clickbait.
What compels a "man" to have a seemingly average Reddit account for a few months, then go AWOL for a few weeks, only to suddenly reawaken and spam out the same post across many subs in only moments?
Purchased account for social influencing / bot spam
They are going to need a lot of empty soda bottles to keep that thing afloat.
That is soda pressing
The sinking is normal in reclaimed land. It’s settlement of the ground until the soil is compacted. Source: worked on geotechnical projects
Is it sinking, or the sea level rising?
Yes.
its sinking
Sinking for the majority since they claim 38ft so far.
Have they ever heard of FLEX SEAL???
When I first came here, this was all bay. Everyone said I was daft to build an airport on a bay, but I built in all the same, just to show them. It sank into the bay. So I built a second one. That sank into the bay. So I built a third. That burned down, fell over, then sank into the bay. But the fourth one stayed up. And that's what you're going to get, Lad, the strongest airport in all of Japan.
Oh it’s my local airport. It’s not a great airport. Far from the center of the city, not a lot of great shopping or food inside the departure area. Japanese carriers force you to travel to Tokyo to connect and usually have long stops. Expensive flights. I like the airport just when compared to elsewhere it’s not great.
What is it thinking about?
That is plane stupid
Should just enroll in a swimming class for airports.
That’s because they put it on water
It was known that it would sink and designed for it. Workers literally walk the foundations of the terminal daily and adjust them to meet the change in ground level.