I was just thinking that and also it's fun to just pretend you understand every single word. I think I heard some city names in there somewhere! Darn closed captioned not working...
@@jon-1976 After you click the CC button to turn it on, click the gear icon, and select "subtitles/CC" and scroll down to English. Not a perfect translation, but not bad at all. Edit: Just noted another user pointed this out, and that it mightn't work this way on a mobile version of RUclips.
@@quoc28mytube only because it's old and times are changing. Storms and storm surges are more powerful because of global warming. However, for the 1970s it's a really cool bit of engineering.
@Skelley-Priest They sure can. Architects do advertise there work. That is how you get new clients. In the end every company that makes anything or provides any service that is not a state run company will have to advertise there business to there costumers. or be very lucky it can only operate on costumers being there advertisers. A company that makes door handles will advertise there door handles to companies that make doors. a company that makes bridges and other big infra structure will advertise to there idea to there client. why do you think that there are so many conventions for so many business worlds. that is there big advertisement campaign.
cost of living and rent are astronomical, and your astronomical rent gets you a closet. Few landlords will rent to foreigners. They may be polite because culture, but prejudice against non-Japanese is prevalent. Forget about opening an in-country bank account if you are a foreigner. People smoke EVERYWHERE including bars, coffee shops and public spaces. The whole regious is prone to frequent natural disasters. Yeah, it's a real land of milk and honey.
@@railgap nah, they dont give 2 sh!ts about foreigners. What did foreigners do to their country to be praised high enough in their community? They arent America. They are better off without extraterrestrial self proclaimed tourists anyway.
In Japan, experts tell the government, "Hey, you should fix this aspect of your infrastructure before it becomes a problem" and they fix it. Meanwhile in America states ignore cracked bridge supports for years and let contractors stress test new bridges without closing the road underneath.
@@FORRESTtheunoriginal I'm an American and I can wholeheartedly agree I mean seriously I'm surprised why so many people want to get in to this crappy country.
too much bureaucracy and redundancies in the worst places. regulation is important but we implement it in the worst ways possible that ends up cutting corners and makes it even harder to undo mistakes. America is that land of good intentions and terrible execution, and the bigger the plan the worse failure. plus japan can say "hey this policy is a mistake for these logistic reasons" and act accordingly while questioning a policy in America is taken as a personal attack on those who support it
yeah, this is what I thought too. However, I think steel is stronger under tensile loads - i.e. more difficult to pull apart than it would be to compress.
@@ALIEN101994 Isotropism has nothing to do with it, or nobody would have ever drawn Mohr circles for isotropic materials. Virtually, steel would resist infinite stress under hydrostatic compression... But you'll heave a hard time going over 2000 MPa in pure tension.
I suspect this has a lot to do with the fact that this gate had to be able to be activated under its own weight. But from a strength point of view: yes, the opposite would have made more sense to me (maybe I'm missing something, though).
As a Dutch person... I'm a bit confused... this model was designed in the Netherlands at the end of the 1950's to control the flow of water downstream of a river. Specifically for inland waterways/rivers, not as a storm surge barrier for a typhoon or tsunami protection. Although this version looks considerably beefier then the ones still in use in The Netherlands. I guess the knowledge back then was simply less.
Think of a suspension bridge. That is also an arch, but all in tension, making much greater spans possible with the use of far less materials. The dams you are referring to are concrete or stone dams, which are stronger in compression. This is a steel dams, and so the arch in tension is a more efficient use of materials
I don't understand anything what they are saying about that dame, but it's seems interesting, wish I could understand what's going on. (From pictures I can see that it's some emergency, anti-flooding system). Greetings from Poland!
Basically what you are imagining. I'm not fluent in Japanese yet, but from what I got, the Roller Gates are essentially flood gates to regulate flooding in the 3 biggest rivers of Osaka. This is to ensure the entire city doesn't get flooded during massive storms such as typhoons or even tsunamis. Osaka's location between these three rivers makes it incredibly vulnerable to flooding and this can be seen in the past before the gates were built.
@@Mavrik9000 Yes, the English translation was pretty good. A few oddities but pretty understandable for the most part. Sad to hear that they're going to demolish such interesting pieces of engineering but I guess they must.
@@tigrosabertooth4757 You are not the original questioner. Are you very sure that you do not understand? Because they did explain it and it is quite simple. Listen closely and if you still have a question, then I will answer it for you. Because you are the only believer in dinosaurs that can point to one that might have existed. You are a smart little fella with belief in the old testament.
This might just be me, but did anyone else hear "lower the blast doors, Lower the Blast Doors!" when they watched this? Also, subtitles at 4:55 read "by 20 years, OSAKA will spend about 360 Circles to rebuild everything into a roller gate type" 360 circles? When was a geometric shape a unit of payment, and how can I get some?
No idea why this was recommended to me but I found it interesting all the same. It's kind of a reverse version of the Thames Barrier in London, only those gates come up from the bottom. The idea was based on how a ball valve works.
For the steel portion of the structure specifically, this is a non-issue; an arch directed this way just operates under tension with the same force as the usual compressional structure. Steel is about equally strong either way. For materials like concrete or soil, like most dams are made out of, they are much stronger in compression, which is why they have their usual shape.
Can someone please explain to me why they pointed the damn arch away from the sea? My understanding of arches is that they are strongest when pointed toward the source of force, that why bridge arches are pointed toward the roads they support. I know how the internet works so I feel that I need to say that I'm not criticising this design, I'm confident that this design was thought out by people way smarter than me. So although I'm pretty sure they chose the best working design, I'm just trying to understand why this design would work better than the traditional use of arches.
It is a valid question. The arch is made of steel. Steel can be capable of high tensile strength. The depicted arch is under tension (hoop stress) when retaining floodwaters behind the concave side of the arch, comparable to the hoops around wooden barrels, or the band defined by any pair of horizontal cross sections through a plastic soda bottle or beer can. Hoops under tension require less stiffness than those under compression. Many dams and bridge arches are made of concrete. Concrete is strong in compression and can be made stiff but it is much less capable of tensile strength than is steel. Applying hoop stress to a concrete arch can break it and doing so is therefore probably inadvisable. That explains why the concrete arches of dams must have their convex sides face into the water behind such dams - the pressure of the water creates compressive force in the concrete arch. Disclaimer: This is just my understanding of the issues. I am not an engineer and might be in error.
@@haroldsmith45302 You are right when you say concrete is stronger under compression stress than it is in tensile But steel on the other hand is an isotropic material. So it is as strong in compression as in tensile However, the shape of a part will have influence on its strength under compression. An elongated part will suffer "buckling" phenomenon ; the piece will bend a little and thus "less material" will oppose to the force. Once buckling reaches a critical point, nothing can be done and the piece almost instantly get "crushed"
When there is a tsunami, only close the arch dam part way. Lower it to leave 1 meter of space below it. If it gets jammed and won't move, the runoff water can still get under it and run out. The tsunami can't get under fast enough to do the most damage. There will still be flooding from the tsunami, but the arch dam will not trap the water in.
@@vytisagafonovas3887 That would depend on the strength of the joints. If it a gap below the gate during tsunami, I think the most likely scenario would be the joints to break, adding the gate itself as one of the debris that the tsunami brought into the city.
Strange that they made the arch the opposite way you would expect as all the force in a storm surge or tsunami will come from the sea and they have the inside of the arch towards the sea making it weaker.
I was confused about that as well, but apparently it has to do with installing the supports for when the arch is down, and those have to be on the river-side.
I do not understand a word, but from what i see, the gate is build in the wrong direction? Normally every dam is build in that way that the curve points to the higher water, so the force is lead as a pushing force to the foundation at the side left and right. Here it looks like the water pressure pulls at the bearings?
why not just make the gate fall to the other side? that way the arch will send the whole impact force to the roots of the gate, they'd need only to reinforce them
via google translate: Osaka is said to be the city of water that develops with the sea and rivers. On the other hand, "Sluice Gate" has protected the city of Osaka for many years from the high tide caused by the inevitable typhoon. In particular, "arched floodgates" are installed in places where the river is wide. It is a famous floodgate only in Osaka, but it is about to disappear soon.
Please forgive my ignorance -- I am no engineer by any stretch of the imagination -- but would someone be so kind as to explain why the arch is not lowered in the opposite direction? Wouldn't water hitting the top of the arch be better deflected, rather than pressure the seam from the inside out?
But... surely the weak seam in the arch can be fixed... as for the issue of lack of power in a disaster to raise it again, how is the water gate better?
They apparently lack the mechanism to lower it without power, even though it only needs a small push away from top position before gravity takes over. If the high water may come from different sides in different disasters, they just need the ability to lower the arch either direction as needed. This video is filled with the kind of bullshit arguments used by people that want to replace all the old things in the world without understanding the abilities.
So the arch have two functions? Primarily a force shock absorber from storm surge and tsunami to slow it down, and flood regulator delaying the water flow? I wish I understand nihongo. So what this gate on 0:16? That may also control the body of water...
They are replacing the arch with the drop gate style shown at 0:16. Two reasons: (1) They modelled the water force in a tsunami can break the arch. (2) The arch needs power to be both raised and lowered; if the earthquake disrupts power, the arch could not be lowered to prevent the tsunami.
I wonder I wonder if there would be a cheaper solution to the tsunami problem then simply replacing all of it. For example, if the problem is just the seam, why not weld an additional metal plate? Or if that won't work, what if they could rig the thing to turn the other way? I mean, it's obviously physically built to only lower in One Direction, but if it could be turned around in the event of a tsunami that would change the way the water flows into it. Alternatively, what if they just added a new tsunami gate at one point and continue to use the other Gates for any water that gets over the tsunami gate? And then adding some kind of bypass for water to get around in the event of mechanical failure, which really they should have done anyway.
I would have thought the arch would have faced the incoming water. It would be immensely strong in that direction. Am I missing something as far as which way they are trying to stop flows?
An arch has the greatest strength when the load bears down towards the top of the arch. I wonder what led them to reverse the structure so the force of the water would push on the sides towards the top. This seems to me to completely negate the structural advantage of the arch. It's opposite to the way dams are built. Had they built it the other way around the force of the water would press the seam at the top together, not apart.
TRANSLATION: Osaka has developed along the sea and rivers, and is known as the city of water. For many years, sluice gates have protected the city from the inevitable storm surges caused by typhoons. Arch-shaped sluice gates have been installed in areas where the river is particularly wide. They are unique to Osaka, but they are about to disappear. (Broadcast on February 5, 2020, MBS TV "News Mint! From "What You Need to Know! from "News Mint!
For the English viewer, they decide to demolish the arched type flood gate and change it to roller gate type flood gate because several weakness 3:27 one of them is when tsunami hits, the center and side part might suffer damage from the wave force which possible make the gate to stop functioning and cause water from upstream to overflow back to the upstream. 4:00 Another issue is that the gate is operating by electric if earthquake happen and the electric supply stops supplying the gate will not able to function to stop any possible tsunami cause by the earthquake.
Why not have the arch face the other direction? Like an aluminum can or wine bottle, there's a dome (revolved arch) at the base that contains the pressure.
Is the seam in the middle because of manufacturing limitations? I can't think of any reason to put that there, especially given that it's a weak spot in a very important location that they specifically cited as a reason for its removal.
2:05
こう見ると水門って大事やな。
がちすげーじゃん
Onkrfa, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Not even sure how this got recommended to me but watching this really feels awesome. Nice engineering, Japan! As always.
Godzilla is not impressed.
I was just thinking that and also it's fun to just pretend you understand every single word. I think I heard some city names in there somewhere! Darn closed captioned not working...
@@jon-1976 After you click the CC button to turn it on, click the gear icon, and select "subtitles/CC" and scroll down to English. Not a perfect translation, but not bad at all. Edit: Just noted another user pointed this out, and that it mightn't work this way on a mobile version of RUclips.
@@matambale Thank you, I knew I must be missing something. Appreciate that!
@@matambale Thanks !
手前に水門作ってから壊さないと、
タイミング悪かったら…
んだよ？はっきり言えやチー牛
確かに、先にローラー式作ってからだよね
20年後にはトラフ地震発生してるよね
この関係、終わりにしましょう
@@chosunhi
そんな事も分からないなら、黙っておいた方が良い（笑）
かっこ悪（笑）
@@chosunhi
え、死にたい以外のコメ初めて見たわ
こりゃ珍しい
Lately I've had a strange fascination with Japanese infrastructure. They definitely think outside the box.
It reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&.oojha
3 billion yen cost though, account for inflation
Whe had tese in the Netherlands for some time now nl.m.wikipedia.org/wiki/Stuw-_en_sluizencomplex_Amerongen
Actually, the engineers decided to dismantle this. It will not protect. Watch til the end!
@@quoc28mytube only because it's old and times are changing. Storms and storm surges are more powerful because of global warming. However, for the 1970s it's a really cool bit of engineering.
子供の頃、毎日この水門を見てすごしました
北津守のシンボルだったこの緑色の水門がなくなるのは本当に寂しい限りです
本当に50年間お疲れさまでした
そして北津守出身者にはいつまでも心の中にこの水門の風景は残っているでしょう
北津守出身。
家から見える。
なくなるんですね。
なんか寂しいです。
It's sad to see it go, it did a great job 🇦🇺
Oyeqya, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
小さい頃「こんな橋渡られへんやん」と思ってた。
それなw
ああ、観光用として残すのはアリですね。
ただ、可動橋としてはダメかなあ。。
誤作動で閉門したっきりになったらヤバイ。
ただゲームでは重要な移動施設だけどねｗ
小さな頃から関西の賢いお子さんらしい
ツッコミ形式の疑問ですね笑
素晴らしい
@@hさん-h7j なんか話変わってね？w
可愛い勘違い
Why it is we don’t celebrate engineers and their teams more than celebrities and politicians is beyond me.
As someone who sucks at math, I have immense respect for engineers.
come to the Netherlands here our engineers are glorified like no other. They keep us dry.
Most celebrities lives aren't worth celebrating. When you turn the TV off they vanish.
Bernie bros we got goo cocky.......
@Skelley-Priest They sure can.
Architects do advertise there work.
That is how you get new clients.
In the end every company that makes anything or provides any service that is not a state run company will have to advertise there business to there costumers. or be very lucky it can only operate on costumers being there advertisers.
A company that makes door handles will advertise there door handles to companies that make doors.
a company that makes bridges and other big infra structure will advertise to there idea to there client.
why do you think that there are so many conventions for so many business worlds.
that is there big advertisement campaign.
「台風や高潮から大阪守ってきたのにな…」
好き
この門は無くなるんじゃない。次の姿に変わるだけさ
Odaexa, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
よく渡船場を使って川を渡る時に見ていた景色なのでこれが無くなるのは少し寂しい…… でも大阪を守るためなら仕方ないか……
Japanese cleanliness always amazes me, sure clean streets are one thing but also their buildings and walls like damn this is so picturesque.
молодцы китайцы все могут все умеют! удачи им!
cost of living and rent are astronomical, and your astronomical rent gets you a closet. Few landlords will rent to foreigners. They may be polite because culture, but prejudice against non-Japanese is prevalent. Forget about opening an in-country bank account if you are a foreigner. People smoke EVERYWHERE including bars, coffee shops and public spaces. The whole regious is prone to frequent natural disasters. Yeah, it's a real land of milk and honey.
@@railgap Bruh, while what you said is not wrong, the guy only said it looked clean and pretty. why do you feel the need?
@@matthewc9934 maybe he just had a bad experience in Japan
@@railgap nah, they dont give 2 sh!ts about foreigners. What did foreigners do to their country to be praised high enough in their community? They arent America. They are better off without extraterrestrial self proclaimed tourists anyway.
50年ももてば十分やろ。
しかも水に触れてる物だしね
流石日本
360億掛けて水門作る必要ないね。住む人間の自己責任。
@@マーサabc そんなこと言ったら住める土地結構減るからなお前
@@マーサabc その考え方は頭悪いよ？
@@マーサabc 名前可愛いな
予算の制約があるとはいえ南海トラフを想定して20年後完成は余りに遠いなあ
こういう時に臨時予算を下さい出したいと言い難いのが
日本の行政の一番の問題だよねえ
いつ災害が発生するか分からないwww
南海トラフ(に限らず地震)は何回でも来るし予測も出来ないからなぁ
予算のせいではないと思いますよ。専門家ではないのでよくは分からないのですが3大水門のような大きさの水門では工期が5年以上のことが多く7年の工期は決して長くないようです。311で壊れた水門の復旧工事を急いだ発注方法をした結果計画の見直しが何度も発生したりで費用も工期も倍増したなんて酷いことになった前例もあるので丁寧に進めることはいいと思います。それに加えて大阪府の津波対策において三大水門の更新はかなり高い優先位置にあってさらに早急な工事が必要と知事答申があるので予算がかかるからと軽んじられたり先送りされた結果の20年ではないと思います。
@@bt-4226 311では土木需要が過大になりすぎていて予算よりも建設作業員の確保などがボトルネックになっていたので、平時の更新の参考として引き合いに出してくるのは不適切。
こんだけでかいやつなら地盤の調査とか設計とかもあるだろうし予算あればはやくなるってもんじゃないやろ
何気なく見てた景色だけど、こうやって解説を聞くとまた改めて見てみたくなるな
It reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&.iaofa
Ohrxpa, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
このようなアーチ型が大阪市にあったなんて初めて知りました。
長い間ご苦労様でした。
大阪って街中散歩していて、急に明治大正感な建造物見つけて調べたら、貴重な建造物や遺構だったというのが多いので勉強になります。
アーチ型はロマンがある
わかる
カンカンヘッドは？
@@太極拳人間 誰もそんなこと言ってないよ
@@太極拳人間 救えます（錯乱）
@@太極拳人間 さん、
いままで救ってきたかと。
今の問題は「巨大津波時にアーチは負ける可能性」
「電源喪失時に稼働できない」なんで。。
やり替える間に南海起きる確率高いから作りながら残しとくのが一番だけどな。ないよりはましだから
@@bt-4226 調べて頂いてありがとうございました。
ありよりのあり？
別に作って壊さなくてもいいと思う。土地不足なのかな？
正味南海トラフなんか来たらみんな死ぬから関係ねえけどな
確率は低いだろ。
In Japan, experts tell the government, "Hey, you should fix this aspect of your infrastructure before it becomes a problem" and they fix it. Meanwhile in America states ignore cracked bridge supports for years and let contractors stress test new bridges without closing the road underneath.
Thats because thats public spending, and Americans 1. love to privatize everything and 2. would rather buy 15 fighter jets than fix roads.
Then there China and their tofu dreg project oof
@@FORRESTtheunoriginal I'm an American and I can wholeheartedly agree I mean seriously I'm surprised why so many people want to get in to this crappy country.
too much bureaucracy and redundancies in the worst places. regulation is important but we implement it in the worst ways possible that ends up cutting corners and makes it even harder to undo mistakes. America is that land of good intentions and terrible execution, and the bigger the plan the worse failure. plus japan can say "hey this policy is a mistake for these logistic reasons" and act accordingly while questioning a policy in America is taken as a personal attack on those who support it
@@FORRESTtheunoriginal private jet and private heli are always something
津波で押し流されるより大雨で浸水の方がマシじゃない？
完成までは残しとこうや
場所とかの問題なのかなあ...
当然、新たなものを作りながらの解体になると思いますけど。
I expected the water force to be in the other direction. That would use the compression strength of an arch and possibly be stronger?
yeah, this is what I thought too. However, I think steel is stronger under tensile loads - i.e. more difficult to pull apart than it would be to compress.
@@timeluster No. Steel is isotropic
@@ALIEN101994 Isotropism has nothing to do with it, or nobody would have ever drawn Mohr circles for isotropic materials. Virtually, steel would resist infinite stress under hydrostatic compression... But you'll heave a hard time going over 2000 MPa in pure tension.
I suspect this has a lot to do with the fact that this gate had to be able to be activated under its own weight. But from a strength point of view: yes, the opposite would have made more sense to me (maybe I'm missing something, though).
I think the answer to that lies at 3:32
皆さんお気づきだろうか…
津波が発生したとき、誰かが水門の操作に足を運ばなければならないことに。
3.11の時も命を賭けて水門を閉めに行った消防団員が多く亡くなりましたね。
なので現在は一級河川の水門などは
遠隔操作できるようにどんどん改修されていってます。
@@kzrymngw4279 でもそうすると電動になって災害時には操作が…以下無限ループ
？？？｢お前らは先に行け！！ここはあたしらが食い止める！｣
@@ごーごー-i3z 水門前まで足を運ぶ職員を憂いてるんでしょ
@@ごーごー-i3z
確かにそうですね。言葉足らずですみません m(._.)m
最近は自動開閉樋門という電力に頼らない水門もありますね。
近所の樋門(堤防に付いている水門)の例なのですが、
以前は、大雨の時に川の水が民家の水路に逆流しないように当番がハンドルを回してゲートを閉じていました
でも最近工事をして、
川の水位上昇で勝手に動いて閉まる自動開閉式になりました
危険な水門当番が無くなって本当ありがたいです
学説によると10年内に南海トラフの可能性がでているらしいけど、
20年じゃ間に合わないし、そもそもその状況下で果たして
水門以外の所の補強も間に合うのかどうか。
なんとしても最小限の被害で抑えるように逐次対応をとってほしい。
大阪は南海トラフによる被害が1番大きくなるらしいですね。自分は南海トラフ地震圏外住みなんで関係ないですが
本物やん！
政府だけでなく国民が政府に協力して早く避難できるかにもかかっていますね。この間の地震の際も大人より子供の方が危機感持っていたので。国民の意識が下がってきてるのでは？とも思いました。
@ノーネーム ですね。お互い気を付けましょうね
こんなところでアナタを見るとはｗｗ
北海道も大きな地震がある可能性があるけどどういう対策とってるのかな
43号からみるとこの水門ユニバを跨ぐ形で見えるんだよなー。大阪でも好きな景色の一つ
見てみたいです！
批判してる人は最後まで動画を見ているのか…
みてないんやで、こういうやつらは「見ないで低評価」とかすらするしな
不謹慎だけど、世の中には災害で人が亡くなられてる動画を内容も見ずに低評価押すやつだっているんやで。
アーチが何をするのかと思ったが、倒すシーンでようやく分かった。
いや、サムネで理解できる代物だろ…
理解力弱くね？
@@しやむげーむす 理解力とは
@@しやむげーむす くそっwww腹立つww
@@しやむげーむす 煽ってる時点でお察し
@@しやむげーむす 失礼な人
どうせならどっちにも倒せる水門で
お願いいたします。
Oviowa, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
①アーチ水門の厚みの補強 ②非常電源の設置 ③油圧の2重系
④開閉ロープ用重力バランサ（円弧式カウンターウェイト）追加設置
そうそう、こういう改修工事でいけそうだよね。
@@masakiizawa5754 いけないから新規に作ると言ってるんでしょうね
一つの川を一つの水門で護ってるのもリスクが集中しすぎるって事なのでは？
例で挙げられていた他の水門は３つのゲートで構成されていたよね。
一個ダメになっても他の２個は開閉できるなら少なくとも水は流せる。
next video: go watch the "horizontal" gates built by the Dutch to guard the Netherlands from the North Sea. much wider inlets to protect.
Aren't most of those scheduled to be demolished/decommissioned in the next 20 years?!
@@_Teorias_ No, just modified. The arche bend barrier is also copied from the Dutch, they had those back in the 1950s already.
Ogjkra, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
As a Dutch person... I'm a bit confused... this model was designed in the Netherlands at the end of the 1950's to control the flow of water downstream of a river. Specifically for inland waterways/rivers, not as a storm surge barrier for a typhoon or tsunami protection. Although this version looks considerably beefier then the ones still in use in The Netherlands. I guess the knowledge back then was simply less.
I am confused about how the river doesn't back up and overflow.
数十年後、ローラー水門は危険だとして、新たな
水門を建設するために、必要とされる予算が
け、建設が...遅...れ
ｳｵｵｵｵｱｱｱｱ\( 'ω')/ｱｱｱｱｱｯｯｯｯ!!!!!
一時的に建設を中断することに
当たりそうだから今のうちにコメ残しておこう
充電切れてて草
Why is the high water on the concave side? I would expect the load on an arch to be on the convex side.
I was wondering the same thing.
Was just about to comment the same thing lol...
Because it was designed by an arch villain.
Inside was a river while the outside is the sea.
Think of a suspension bridge. That is also an arch, but all in tension, making much greater spans possible with the use of far less materials. The dams you are referring to are concrete or stone dams, which are stronger in compression. This is a steel dams, and so the arch in tension is a more efficient use of materials
逆に倒せたらトンネルの要領で津波にも多少対処できそう（小並感）
同感
その場合、水門は耐えられるけど、流れの力がすべて左右に方向をかえられて、水門以外が壊滅しそう・・・
同じくそう思いました。
でも根本？の構造が一定方向にしか曲がらなかったり、ワイヤーの巻き取りとかも反対側にやり直したりしそうで大変そうですね。いっそ新しいの作っちゃえ！ってなったのでしょうね。
1970年に作った人が逆に倒せるよう作っていれば、作り替える必要はなかったんだよね。税金を使ってまた新しいの作って 結局災害は防げなかったりするのかもね。考えている事が幼稚なんですね😆
当時は津波の危険性が今ほど認識されてなかったのでは
すげぇあの台風21号の高潮被害防いでたんだ…
I don't understand anything what they are saying about that dame, but it's seems interesting, wish I could understand what's going on. (From pictures I can see that it's some emergency, anti-flooding system). Greetings from Poland!
Basically what you are imagining. I'm not fluent in Japanese yet, but from what I got, the Roller Gates are essentially flood gates to regulate flooding in the 3 biggest rivers of Osaka. This is to ensure the entire city doesn't get flooded during massive storms such as typhoons or even tsunamis. Osaka's location between these three rivers makes it incredibly vulnerable to flooding and this can be seen in the past before the gates were built.
1. Click the CC button, gear icon, Autotranslate, gear icon, desired language.
@@Mavrik9000 Yes, the English translation was pretty good. A few oddities but pretty understandable for the most part. Sad to hear that they're going to demolish such interesting pieces of engineering but I guess they must.
@@Mavrik9000 i tried, but either it takes a while to be translated, or it doesnt work for japanese to english or german :-(
@@knuffelbaer1971 It worked for me for English.
I've never seen something like this. Amazing engineering indeed.
Osunla, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Wouldn't it work better as an arch if it was going the other way?
No.
@@pauldailey4477 why?
@@tigrosabertooth4757 You are not the original questioner. Are you very sure that you do not understand? Because they did explain it and it is quite simple. Listen closely and if you still have a question, then I will answer it for you. Because you are the only believer in dinosaurs that can point to one that might have existed. You are a smart little fella with belief in the old testament.
水門・立こうも大事！
でも「早め避難」が１番大事！
もっといいのは移住
関西から離れたくないのなら
奈良県に。
大阪府下だったら吹田や箕面、東部の高台
@@karateru
それが一番 危険なエリアから離れろ
水門好きとしては壊される前にぜひ見ておきたいところ
水門とは聞いてたけど
閉まるとこ初めて見たわ
This might just be me, but did anyone else hear "lower the blast doors, Lower the Blast Doors!" when they watched this?
Also, subtitles at 4:55 read "by 20 years, OSAKA will spend about 360 Circles to rebuild everything into a roller gate type"
360 circles? When was a geometric shape a unit of payment, and how can I get some?
No idea why this was recommended to me but I found it interesting all the same. It's kind of a reverse version of the Thames Barrier in London, only those gates come up from the bottom. The idea was based on how a ball valve works.
Ozjoea, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Why does the arch goes toward the low side? This makes the gate pull from the holds. Normally, all dams are build convex toward the high side.
For the steel portion of the structure specifically, this is a non-issue; an arch directed this way just operates under tension with the same force as the usual compressional structure. Steel is about equally strong either way. For materials like concrete or soil, like most dams are made out of, they are much stronger in compression, which is why they have their usual shape.
IMPRESSIONANTE! Talvez apenas a holanda tenha um sistema parecido com este.
Obtzma, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
アーチ型水門は景観的にも良かったが、
南海トラフの地震を想定した時には実益性が優先されるということかー、仕方ないね
様々なタイプの水門や淀川などの防潮鉄扉の"建設"と"実運用"実績のある大阪のデータは貴重。利点と欠点が後に活かされる。
Can someone please explain to me why they pointed the damn arch away from the sea?
My understanding of arches is that they are strongest when pointed toward the source of force, that why bridge arches are pointed toward the roads they support.
I know how the internet works so I feel that I need to say that I'm not criticising this design, I'm confident that this design was thought out by people way smarter than me. So although I'm pretty sure they chose the best working design, I'm just trying to understand why this design would work better than the traditional use of arches.
It is a valid question.
The arch is made of steel. Steel can be capable of high tensile strength.
The depicted arch is under tension (hoop stress) when retaining floodwaters behind the concave side of the arch, comparable to the hoops around wooden barrels, or the band defined by any pair of horizontal cross sections through a plastic soda bottle or beer can. Hoops under tension require less stiffness than those under compression.
Many dams and bridge arches are made of concrete. Concrete is strong in compression and can be made stiff but it is much less capable of tensile strength than is steel. Applying hoop stress to a concrete arch can break it and doing so is therefore probably inadvisable. That explains why the concrete arches of dams must have their convex sides face into the water behind such dams - the pressure of the water creates compressive force in the concrete arch.
Disclaimer: This is just my understanding of the issues. I am not an engineer and might be in error.
@@haroldsmith45302 You are right when you say concrete is stronger under compression stress than it is in tensile
But steel on the other hand is an isotropic material. So it is as strong in compression as in tensile
However, the shape of a part will have influence on its strength under compression. An elongated part will suffer "buckling" phenomenon ; the piece will bend a little and thus "less material" will oppose to the force. Once buckling reaches a critical point, nothing can be done and the piece almost instantly get "crushed"
解体せずとも
2つ目を作ればいいんじゃ!?
砂防ダムとか3重4重になってるよね
内容見ましたか？
動かなくなるのがまずいんです
内容見たのですが、アーチ型が破損・電源の問題で開かなくなる問題が起きる可能性があるのに対して、ローラーゲート型は電源は無くても自重で閉めることが出来る、って対比になってないですよね。
I don't know why this got recommended to me but it was cool. Thank you Nippon. Sincerely, a swedish guy.
When there is a tsunami, only close the arch dam part way. Lower it to leave 1 meter of space below it. If it gets jammed and won't move, the runoff water can still get under it and run out. The tsunami can't get under fast enough to do the most damage. There will still be flooding from the tsunami, but the arch dam will not trap the water in.
Coudnt tsunami just lift it if its not lowered enough?
@@vytisagafonovas3887 That would depend on the strength of the joints. If it a gap below the gate during tsunami, I think the most likely scenario would be the joints to break, adding the gate itself as one of the debris that the tsunami brought into the city.
Very glad to see that Japanese were able to rebuild after Godzilla caused so much damage throughout the late 60s all the way in to the late 90s.
lol
めっちゃ大変でした()
外側に突き出してると思ったらモロに水圧かかる方向にアーチしてたｗ
俺もこの動画みるまで同じ事思ってた。
閉まってる状態見たことなかったから…
川→海を想定してるからな、、海→川の津波は想定してない
@@oops6413
川→海は要らないでしょ。そもそも満潮の時に逆流を防ぐ為のものなんですから
逆だったら波来たときに円の端から外に溢れるからじゃないか？
Oebdaa, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Very interesting but what happens to the water when it is blocked? Surely it overflows into the surrounding areas?
godzilla drinks it up, maintains balance, lame we know
逆向きに倒せば良いじゃん
それな、なんなら開いた時に円形なるようにもう一個作れば
同じことを考えたｗｗｗｗｗ
津波なめたらだめよ
@バーバパパ 急に堅くて草 なんか正論＝絶対正義とか思ってそう（偏見）
@バーバパパ 思い付きって案外大事よ
Strange that they made the arch the opposite way you would expect as all the force in a storm surge or tsunami will come from the sea and they have the inside of the arch towards the sea making it weaker.
I was confused about that as well, but apparently it has to do with installing the supports for when the arch is down, and those have to be on the river-side.
Onzqva, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
20年かかんの？その間に来るやろ
二十年後にも言ってそう
@@ニキ-h2j 何いってんだ
@@ポチ-l9j 理解できないのか...
ポチ 化石燃料もそうだけど、あと三十年で終わる的なことを四十年前くらいからずっと言ってるんやで
@@ポチ-l9j 何言ってんだ
新しいのが出来てから解体するんじゃないんか？
360億の工事に20年もかけるんか…
ドカーンと行こうぜ
殆どが用地買収期間
工事期間は3年〜6年かな
I do not understand a word, but from what i see, the gate is build in the wrong direction? Normally every dam is build in that way that the curve points to the higher water, so the force is lead as a pushing force to the foundation at the side left and right.
Here it looks like the water pressure pulls at the bearings?
why not just make the gate fall to the other side? that way the arch will send the whole impact force to the roots of the gate, they'd need only to reinforce them
Steel is not as strong under compression as it is under tension.
@@mabriff Steel is isotropic
02:04
頭のいい人教えてください
なんで上流に水が流れ込むのを防ぐんですか？なんで水流が下流に向かわないんですか？
海から高潮が入ってくるのを塞いでるんじゃない？
@@Channel-qm3ql
丁寧に説明いただきありがとうございます。たしかに動画内で高潮対策と言っていますね。「高潮」の意味をよく知らなかったので調べました。
ありがとうございます。
@@のり本舗 いえいえ、こちらこそいい方きつくなってすみませんでした。
アーチの向き逆だったんちゃう？（
逆に倒せば問題無さそう
冗談かもしれんが、今から反転する方法を模索したら？
上流からの被害がデカかったのかね？
それは思った
これ
Shouldn't the arch face outward to distribute the face from the waves instead of facing inward?
500トン支えるワイヤーすぎょい
ｶｶﾞｸﾉﾁｶﾗｯﾃｽｹﾞｰ
ワイヤーって地味に引っ張る力にはめちゃくちゃ強いですからね
1cmの太さがあれば5トンまで耐えられるらしいです
@@山田ゴンザレス-u2y じゃあ直径10cmなら、500t出来ますか？
@@boiledhard1997 そうですね、規格の表を見た感じ直径の2乗に比例するようなので、10cmで500tになると思います。
実際はこんな単純な計算ではないとは思いますが、、
@@山田ゴンザレス-u2y ありがとうございます
無知コメントで申し訳ないですが先に新しい水門を設置してから今の古い水門を解体するんでしょうか？もし解体してから新設となればその解体中、新設中に津波などの水害が起こった場合どうするんでしょうか？いやまぁ正直南海トラフなどでできた津波が来た場合川が逆流するより市街地に津波が押し寄せる気もしますが…
20年間で津波来そうやな、、、
At 4:55, the English subtitles say they'll spend about "360 circles" to rebuild everything. What does that mean?
It's oku yen.
Which as shorthand, the math cancels out to basically mean $1,000,000.
So 360 million dollars, apx.
@@redfish337 okay. Thanks!
人間じゃないのに何故か人間のように見えてしまう。偉人だ
Ofqlma, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
via google translate:
Osaka is said to be the city of water that develops with the sea and rivers. On the other hand, "Sluice Gate" has protected the city of Osaka for many years from the high tide caused by the inevitable typhoon. In particular, "arched floodgates" are installed in places where the river is wide. It is a famous floodgate only in Osaka, but it is about to disappear soon.
Well thank you for this. For real!
@@jon-1976, you're welcome
Once again, we are united thanks to the recommendations
Ojthqa, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Please forgive my ignorance -- I am no engineer by any stretch of the imagination -- but would someone be so kind as to explain why the arch is not lowered in the opposite direction? Wouldn't water hitting the top of the arch be better deflected, rather than pressure the seam from the inside out?
いろいろな技術や経験の積み重ねがあるから時代とともに作り変えるのだろう。
But... surely the weak seam in the arch can be fixed... as for the issue of lack of power in a disaster to raise it again, how is the water gate better?
They apparently lack the mechanism to lower it without power, even though it only needs a small push away from top position before gravity takes over. If the high water may come from different sides in different disasters, they just need the ability to lower the arch either direction as needed. This video is filled with the kind of bullshit arguments used by people that want to replace all the old things in the world without understanding the abilities.
アーチ橋やアーチ式ダムの原理を知ってると
『閉める方向が逆じゃね？』
と思うのは私だけでは無いはず
逆に閉めたら津波にも強そうとも思うはず
So the arch have two functions? Primarily a force shock absorber from storm surge and tsunami to slow it down, and flood regulator delaying the water flow? I wish I understand nihongo. So what this gate on 0:16? That may also control the body of water...
They are replacing the arch with the drop gate style shown at 0:16. Two reasons: (1) They modelled the water force in a tsunami can break the arch. (2) The arch needs power to be both raised and lowered; if the earthquake disrupts power, the arch could not be lowered to prevent the tsunami.
it seems the almighty algorithm decided that I like arching water gates now, so be it
Water gates meta?
Oopeaa, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
I wonder I wonder if there would be a cheaper solution to the tsunami problem then simply replacing all of it. For example, if the problem is just the seam, why not weld an additional metal plate? Or if that won't work, what if they could rig the thing to turn the other way? I mean, it's obviously physically built to only lower in One Direction, but if it could be turned around in the event of a tsunami that would change the way the water flows into it. Alternatively, what if they just added a new tsunami gate at one point and continue to use the other Gates for any water that gets over the tsunami gate? And then adding some kind of bypass for water to get around in the event of mechanical failure, which really they should have done anyway.
①アーチ水門の厚みの補強 ②非常電源の設置 ③油圧の2重系
④開閉ロープ用重力バランサ（円弧式カウンターウェイト）追加設置
などの改修工事をすれば、新規更新より安く上がる可能性があるのでは？
厚みの補強は無理なんだよ。構造的に
I would have thought the arch would have faced the incoming water. It would be immensely strong in that direction. Am I missing something as far as which way they are trying to stop flows?
I thought that the stronger side would have been the convex rather than the concaved.
新しい水門完成してから壊せばいいじゃん
So is this japan's version of the 11' 8" bridge?
水門を倒す方向を逆にした方がという意見ですが、アーチの頂点を海側に倒し津波を堰き止めようとした時、水門の両端部・操作室の有る部分に大きな力が作用します。
その場合、現在のままでは力に耐えられず付近の堤防ごと破損すると考えられます。
また津波の力に耐えられるような端部の構造物を作ろうとすると、堤防の大きさ・費用は巨大なものなります。
設計、運用実績があり、建設費用が相対的に安いローラーゲート式水門に作り替えるのは公共工事として妥当な判断では無いでしょうか。
アーチの力に対して引っ張り側の力を持たせる方が構造的には難しいと思います。工費的にもそれは同じです。おそらくですが氾濫時に両脇に少なからず被害が出るのを嫌ったのではないでしょうか。
@@KH-rn7et
アーチの力学的な特性についてはK H様の指摘の通りかと思います。
私の意見はあくまでアーチの頂点を海側に倒した時、現在の設計では津波の力に耐えることができないのでは無いか？と考えたものです。
また以下、現場条件、設計上の制約等分からない状態での私の考えですが、
水門がアーチ構造をとった理由
・水門施工当時、現場は船舶の往来が多く水面上に大きな高さ・河川中央に大きな幅を確保する必要があった。
アーチの頂点が上流側に倒れる理由
・水門を境に、管理部門が分かれており、河川課の管理する水門構造物を海に倒すことが出来なかった。
と言った理由からアーチ構造、閉門動作方法が決定されたのではないかと考えてます。
映像内で、河川側水面より5mも海面水位が高い状態でも水門に問題がなかったことから、何故高潮に対しても不利な方向にアーチを倒すのか不思議に思っております。
何かご存知の事柄がありましたれ御教授頂けますと幸いです。
長文失礼致しました。
@@24okojyo77
やっとわかりました。
海側の水よりも川の流れに対応するために設計したのだと思います。南海トラフ地震が割と最近になってこれは大変だと騒がれだしたのでそもそも当時の設計として津波が含まれていなかったのだと思います。
The Japanese are very brilliant and resilient...素晴らしいビデオ、私は多くのことを学んだ、ありがとう
An arch has the greatest strength when the load bears down towards the top of the arch. I wonder what led them to reverse the structure so the force of the water would push on the sides towards the top. This seems to me to completely negate the structural advantage of the arch. It's opposite to the way dams are built. Had they built it the other way around the force of the water would press the seam at the top together, not apart.
Oeiuya, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Sub-titles would have been nice, so us foreigners could understand what was being said.
It had subtitles using the [CC] Closed Caption option.
アーチ水門も予備に残しておけば？ まずローラーゲート水門で堰き止め、それでも越流する水をアーチで受ける。水勢が下がれば、次に開かない不良が出ない･･･とは言い切れんか（トーシロす ｻｰｾﾝ）
それともう一つ疑問なんだが、なんでアーチは左右分割なのか。溶接して一体化したらいかんのだろうか。
動画見る限り左右分割でなく、中央で溶接なり別の方法なりで接着してるのでは？
全部一体物にすべきという意味合いなら、これだけのサイズの一体物を製作するのは困難かなと思います。
中央部は左右ワイヤー上下の歪みの逃げ場所として機能していると考えるのが妥当かな
今までこの水門に大阪の街を守られてきたから、感謝この上ない。大阪の誇りやわ。
次の水門も、大阪の街をしっかり守っていただきたいですね。
工事中は、ちょっと守りが手薄になるかも知れないけど、早めの避難をするのが、大阪人の機転やね。
懐かしい
生まれ故郷で良く見る大正区内のランドマークの一つ。
木津川水門は場所が特殊な所で行くことも目の前で見る事もなかったけど、尻無川は大正駅から千島や北恩加島、小林などに抜ける時に使う広くて走りやすい道沿いにあったから、よく見ていた。
これが無くなるのは寂しいな。
It reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&.yiyra
TRANSLATION: Osaka has developed along the sea and rivers, and is known as the city of water. For many years, sluice gates have protected the city from the inevitable storm surges caused by typhoons. Arch-shaped sluice gates have been installed in areas where the river is particularly wide. They are unique to Osaka, but they are about to disappear.
(Broadcast on February 5, 2020, MBS TV "News Mint! From "What You Need to Know! from "News Mint!
Just an English comment. Btw so elegant watergate.
I AGREE, HI FROM RUSSIA
My heart broke a little bit. What a lovely piece of engineering. It's shame to hear that it has been removed.
Получил эстетическое удовольствие, наблюдая, как кабели ложатся в направляющие, когда этот затвор опускается.
Obxjra, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Impressive Engineering....great Vid...thanks from California 2021
木津川の水門に限って言えば横に逃がせる水門があるので川の増水が氾濫につながるということはなさそうですよね
電源喪失で動かないなら発電機を設ければ良いじゃないか？とか
継ぎ目の弱さは果たしてどの程度なのか？とか
継ぎ目が弱いなら強くすればいいじゃないか？とか
ローラー式では船の運行はどうするのか？とか
よくわかりませんね
For the English viewer, they decide to demolish the arched type flood gate and change it to roller gate type flood gate because several weakness 3:27 one of them is when tsunami hits, the center and side part might suffer damage from the wave force which possible make the gate to stop functioning and cause water from upstream to overflow back to the upstream. 4:00 Another issue is that the gate is operating by electric if earthquake happen and the electric supply stops supplying the gate will not able to function to stop any possible tsunami cause by the earthquake.
長年いらないいらないと言われて試運転段階でぶっつけ本番をさせられた八ッ場ダムというのがありましてな
（20年のうちに来そうだから）
あれ、間一髪だったよなぁ。
間に合ってよかったよ。ほんと😥
次は東京にあるデータセンターの移設。
スパコンも次はダムの中に設置。
I don't understand why the gate isn't the other way round. An arch is strongest with the weight at the apex.
Amazing how it's so precise, the cables land directly in the pulleys.
Yes, it's a cool use of cables.
ikr...? first thing i noticed.
thats why it takes 30 minutes to lower the arch it needs to lowered very slowly
Oibjra, it reminds me of *_these mice_* ruclips.net/video/VE6OwKoFSB0/видео.html&
Why not have the arch face the other direction? Like an aluminum can or wine bottle, there's a dome (revolved arch) at the base that contains the pressure.
Don't speak, But I understand perfectly. Japanese ingenuity at it's best, again.
@@uzielweb
Both and more!
Is the seam in the middle because of manufacturing limitations? I can't think of any reason to put that there, especially given that it's a weak spot in a very important location that they specifically cited as a reason for its removal.
水門を逆に倒しては？と言う方がいますが
逆に倒したら水門としての機能が下がると思います
(水門の機能とは、上流の水位を上げない、水を封じ込めて水害を減らすことです)
水を外側に跳ね除けてしまうため陸に水が上がり、河川から離れた内陸の広範囲に水害が広がってしまいますね、
動画上での倒し方は、半円の特性をしっかり活かし、船の航行も可能な、水を封じ込めることができる、素晴らしい形です
しかし、水の勢いが強いと壊れてしまうのが欠点であり、
南海トラフの予想に耐えられないので、新しくする必要がある、と言うことでしょう
逆に倒した場合、津波に対抗できると思うかもしれませんが、
全くの逆効果で、半円と垂直に流れてきた水の力の向きが、外側に向いてしまうので、やはり陸に上ってしまいます、
津波の勢いを殺すこともできません、
(水の力の向きを変えるだけだから{水の勢いを殺すと言う点では動画上の水門の向きが正しい｝)
しかし、壊れないと言う点では正しい向きですけどね
壊れないけど、管理棟が浸水して制御不能になるか
壊れて、最初だけ威力を殺すか
ですかね
津波って跳ね返ると威力増すって聞いたような気がするので
逆向きだと波高くなるのかな
great invention, but what i'm asking just, why the arch go to inside than outside instead ?