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Highest bridge unveiled at more than 2,000ft above ground

independent.co.uk

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Re: Highest bridge unveiled at more than 2,000ft above ground

#151

Post by potato3732842 »

gorgoiler wrote: post #138
nikkwong wrote: post #63

Earlier quoted context omitted.

It's hilariously depressing to imagine how impossible it would be to build something like that in the US. It's not only the fact that it's an engineering feat—it's also the fact that it was built in such a human-centric way. The cafe at the top, the light show with the water. These things are all superfluous, but make these projects exciting and add novelty which makes these areas just fun places to be. The U.S., in…

The Penobscot Narrows Bridge (opened, 2006) was the first thing that sprang to mind. https://en.m.wikipedia.org/wiki/Penobscot_Narrows_Bridge_and... One end has an observation deck, built just for fun! It’s on the slower, non I-95 route up through Maine to Bar Harbor / Acadia National Park.

>non I-95 route up through Maine to Bar Harbor / Acadia National Park.

Which basically means that that whole bit of $$ producing tourism infra is that much closer to everything south.

Re: Highest bridge unveiled at more than 2,000ft above ground

#152

Post by ishouldbework »

gverrilla wrote: post #133
margalabargala wrote: post #45

Earlier quoted context omitted.

And to ensure it would not buckle, per the article. Implying they were not sure it would not buckle, until they drove the trucks on.

That's like saying unit testing implies there are bugs in the code.

If I was sure my code had no bugs, I would not need unit testing.

Re: Highest bridge unveiled at more than 2,000ft above ground

#153

Post by potato3732842 »

margalabargala wrote: post #45
wak90 wrote: post #19

Earlier quoted context omitted.

They deploy trucks to see how the bridge vibrates.

And to ensure it would not buckle, per the article. Implying they were not sure it would not buckle, until they drove the trucks on.

They probably wanted to quantify how much the bridge moved in various ways. There were likely many "it probably won't move more than acceptable in this way, but if it does we've made it easy to add a change here to fix that" facets of the design. All large complex structures undergo testing like this, sea trials for ships being the quintessential example.

Re: Highest bridge unveiled at more than 2,000ft above ground

#154

Post by RajT88 »

FooBarBizBazz wrote: post #148
bko wrote: post #141

Earlier quoted context omitted.

The thing that stuck out to me was this: > The 2,890-metre-long structure, which took more than three years to complete, reduces travel time between the two sides of the canyon from two hours to two minutes. Pretty impressive. I feel like things in the US take a lot longer and cost a lot more. The prime example is the second avenue subway extension which has been planned since 1920. But I just searched for a few sign…

Chinese civil engineers, and engineering orgs, are good because they get a lot of practice. In the West, and especially in the US, individuals and orgs don't get practice, so when they finally do get a new contract they have to stumble around for 5-10 years figuring out all the institutional knowledge that was lost. By the time they figure it out, the project is over budget, so it gets canceled, and then it's 20 year…

To say nothing of the NIMBYism. To acquire the land for use, you have to fight some armies of lawyers retained by a population with a lot of disposable income. (Yes, the US for all her problems has the biggest pool of disposable income in the world)

Re: Highest bridge unveiled at more than 2,000ft above ground

#155

Post by jp57 »

6LLvveMx2koXfwn wrote: post #124

I was going to make some joke about not wanting to be the dude driving over the bridge for the load test - entirely presuming there was some more sophisticated way to load test new bridges . . . but no: https://www.gettyimages.co.uk/detail/news-photo/load-testing...

I hope the engineering team were riding in the trucks.

Re: Highest bridge unveiled at more than 2,000ft above ground

#156

Post by rirze »

x______________ wrote: post #99
xwolfi wrote: post #83

Earlier quoted context omitted.

Well it's not the same game. Here in China we're in this phase of accomplishing big stuff to help each other and flex a bit and wow at our own development. When the British colonized America, it was exactly the same - an insane accomplishment to capture and re-develop that land into something half-working so far away. When China starts capturing and colonizing other continents, you can start being really jealous ! No…

I like the /s here When China starts capturing and colonizing other continents, you can start being really jealous ! We're still doing /s right? This mentality is outdated..

Outdated or not-- it's already happening. China is creating "economic colonization" zones across second/third world nations by lending loans such that countries that can't pay up have to settle by giving up strategic bastions of power.

Take a look at (https://en.wikipedia.org/wiki/Hambantota_International_Port). Overtly, not owned by the Chinese government but you can draw your own feelings.

This is how western colonization started.

Re: Highest bridge unveiled at more than 2,000ft above ground

#157

Post by screye »

lm28469 wrote: post #132
screye wrote: post #15

Very impressive. The economic angle is a bit confusing. Wonder why China thought this was a worthy investment. Guizhou is a poor part of China, without much international tourism or trade. Wikipedia indicates it is meant to increase tourism, but even China's most attractive regions (Beijing, Shanghai, Great Wall, Chengdu, Chongqing) are under-visited. I can't imagine that Guizhou will be on foreign tourist's agenda f…

> Guizhou is a poor part of China Look at Schenzen in the 70s... If you want your country to move forward you need infrastructure, otherwise poor parts stay poor

China's population boom has ended. The 70s boom can't be recreated without sufficient youth to move into the newly urbanized locations.

Re: Highest bridge unveiled at more than 2,000ft above ground

#158

Post by mk_stjames »

6LLvveMx2koXfwn wrote: post #124

I was going to make some joke about not wanting to be the dude driving over the bridge for the load test - entirely presuming there was some more sophisticated way to load test new bridges . . . but no: https://www.gettyimages.co.uk/detail/news-photo/load-testing...

They do this to measure load vs deflection and check agreement with models, not to get anywhere close to yield. It's a low end proof check, drive trucks on, measure deflections, drive trucks off, confirm reset of deflection;

The margin on actual load to a permanent set is likely 2-3x what those trucks are carrying. And the margin to actual failure from just this quasi static loading and no external environmental loads (wind)... even more so.

Unless there was some catastrophic fuck up in construction process or calculations, this is completely safe.

Re: Highest bridge unveiled at more than 2,000ft above ground

#159

Post by thefourthchime »

maxglute wrote: post #50
screye wrote: post #15

Very impressive. The economic angle is a bit confusing. Wonder why China thought this was a worthy investment. Guizhou is a poor part of China, without much international tourism or trade. Wikipedia indicates it is meant to increase tourism, but even China's most attractive regions (Beijing, Shanghai, Great Wall, Chengdu, Chongqing) are under-visited. I can't imagine that Guizhou will be on foreign tourist's agenda f…

> reduces travel time between the two sides of the canyon from two hours to two minutes. Think of it this way. Every 2 hours round trip to 2 minutes saves imported fossil. For trucking/freight that's like ~$80 of diesel both ways. PRC construction workers, though less abundant is cheaper than it ever will be. So best time to build infra is always now, especially one that reduces long tail imports. Every piece of infr…

Yes, but on the other side of the coin is the pending maintenance for all of these projects. You don't just build a road, rail or bridge anad then be done with it. They all require upkeep. If the project itself was a jobs program masquerading as a infra, they'll just let all these fabulous projects rot as it won't make sense to keep them up.

Re: Highest bridge unveiled at more than 2,000ft above ground

#160

Post by imglorp »

bko wrote: post #141
pcl wrote: post #64

I really don't understand all the hyperbole around this bridge. It's a suspension bridge, so the relevant bits are at the pylons, which just happen to be on either side of a huge canyon. It clocks in at #14 on Wikipedia's list of longest suspension bridges, with a main span that is 603 meters shorter (2023 meters vs 1420) than the longest. More interestingly, to me at least, is the fact that 31 of the longest 50 are…

The thing that stuck out to me was this: > The 2,890-metre-long structure, which took more than three years to complete, reduces travel time between the two sides of the canyon from two hours to two minutes. Pretty impressive. I feel like things in the US take a lot longer and cost a lot more. The prime example is the second avenue subway extension which has been planned since 1920. But I just searched for a few sign…

Freakonomics just had an episode about how China is run by engineers, who get things done, while the US is run by lawyers, who prevent things from getting done.
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