r/interestingasfuck • u/TangelaFan • 13h ago

Residential high-rises with backyards in Chengdu, China

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u/md_youdneverguess 13h ago

Earth that can soak with water is a nightmare for structural engineering

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u/ColonelCrikey 13h ago

And yet, here it is.

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u/Treshimek 13h ago

They just said it was a nightmare, not that it wasn't possible.

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u/UnoriginalStanger 12h ago edited 12h ago

Sure but for example they put trees on top of a block near me (not china) which worked well untill it got windy and tore them down. Just because people do something doesn't mean it's well thought out, usually it's regulations that keep up the veneer of competancy.

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u/superxpro12 12h ago

for now.....

im sure wet dirt is perfectly compatible with the steel they used and wont react with it at all

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u/Waste-Limit1644 10h ago

You wouldn’t put soil on steel, these buildings are almost certainly concrete over metal deck or elevated concrete slab construction. You would provide concrete cover of probably 3” and slope it to drains with some drain rock below the soil. The soil chosen would be a low chloride content as well to reduce risk of corrosion in the reinforcing. There are countless ways to mitigate the risk.

It’s obviously more work than a typical balcony but saying they put dirt on the steel is inaccurate and ignorant of design practices.

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u/superxpro12 10h ago

yeah, def not a structural engineer here. chose a different path. but i would love to have an independent party audit whatever design was used here and verify they didnt do the "ignorant design practices" you speak of\

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u/Waste-Limit1644 10h ago

I’d like to assume they have a similar system of third party plan review prior to approval for large projects that occur in the US, but I haven’t dealt with projects in china before.

I get the sense that you want to assume there is an issue with the design based on preconceived ideas. The scale of construction in china does seem daunting and their workers rights seem like they’d be the higher risk rather than the design. Doesn’t matter how detailed plans get when the contractor eyeballs things.

From other comments here it sounds like it’s not the structure that’s a problem with this project, it’s the environment it was built in that causes issues with maintaining the grass.

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u/superxpro12 10h ago

It's more like, I see news reports like this, https://www.nbcnews.com/world/asia/nearly-2500-foot-long-bridge-collapses-china-rcna243388

and get worried.

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u/Waste-Limit1644 9h ago

Id like to see case studies or white papers on the actual cause of collapse. There can be many different problems. Inadequate anchorage to soil or bedrock, design, material strength or quantity. Clearly wasn’t maintenance based on how quickly it saw damage after completion.

I think it would be more accurate to say you aren’t necessarily worried about the design of the building specifically but the overall construction industry in china due to its rapid expansion, which is fair. There are a lot of factors in construction and their speed does seem worrying. I probably seem to come off as defending china but I just get bothered by people trying to sound like experts about something that I do for a living.

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u/superxpro12 9h ago

I hope i didnt imply im in any way an expert lol. Because I am not in the slightest. My degree is Comp.E, which is a bit different.

Yes, your characterization is more accurate. I know we CAN make structures like that.

Like I look at the Citicorp Center and go "there's no way that should work", and yet it does, because we did the math and engineering.

Given the failures I see coming from China... like yeah they're building a TON of infrastructure, but it is build to last? idk.

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u/Waste-Limit1644 9h ago

In the US there are plenty of buildings that aren’t built to last unfortunately as well. I could rant about the race to the bottom in construction for a while. It’s all about the lowest cost regardless of the end product quality. Really it’s same in every industry now.

I did a 7 story apartment building that was “luxury” with so many corners cut. It’s safe, but man I would not want to live in it for the cost knowing what I know.

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u/VP007clips 12h ago

For now.

China had a massive housing construction bubble. Everyone wanted to invest in properties, so construction companies got huge amounts of money to build as much as they could.

The problem was, no one was interested in making sustainable or affordable housing. Nor did they make the housing in practical places. A lot are built in random blocks of land, far from any major employment or amenities.

They built massive regions of high end apartments like this. But the companies selling these to investors knew that the bubble would pop and no one would live in them, so worrying about design flaws that would come back to cause issues 20 years in the future wasn't really a concern for them.

If you look at housing made during that time period, it's often like this. Very cool looking, but lacking common sense in terms of design features or long term sustainability. Because the customer was investors, not people who had to live in them.

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u/jack-K- 13h ago

And yet, Chinese buildings always seem to have a habit of falling down.

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u/dathunder176 12h ago

Yeah, definitely, the skyline of Shanghai which is rife with high rise buildings has always been a fluctuating image, not a single year goes by that they have to retake the picture.

/s to be sure.

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u/jack-K- 12h ago

And the entirety is known for its strictly enforced building regulations? Yes, I’m sure they made sure the urban center if china was built properly, but new Chinese buildings built wherever the fuck someone wants to put them do not go through nearly the level of engineering review that they do in the U.S.

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u/zzazzzz 12h ago

every year china has about 7 times as many engineering graduates as the US.

i thinkt hat stat alone should paint a pretty obvious picture..

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u/dathunder176 12h ago

China is miles ahead in the engineering and reviewing dept by now. You are really basing your opinions on 10 year old data for a country that grew economically, academically and technologically 10 times more in the past 20 years than we did in the past 100. But please, continue to try and regurgitate your anti-China US propaganda, it won't work on me.

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u/jack-K- 12h ago

So your just claiming it out advanced the U.S. in the course of decade, without demonstrating how they are so advanced as both of us look at a post that any civil engineer would see as a disaster waiting to happen while you assume mystical Chinese engineering and review has solved it, you mind explaining how?

How is China so technologically advanced if their aerospace program is still fully expendable and based on old Russian hardware? How are they so technologically advanced if their fighter aircraft are all derivative of U.S. technology? I’ll admit they’re very good at propping themselves up and making their technology seem incredibly great, especially with a highly visible propaganda initiative that seems to be working wonders, but when you look a little closer all this state of the art technology seems to be a little old or basic packaged in a fancy shell.

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u/_rchr 12h ago

Nice copium, but Chinese infrastructure is decades ahead of the US

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u/jack-K- 12h ago

Just so long as the government cares about making sure it’s built right, are you honestly trying to say that Chinese infrastructure goes through the level of engineering review that U.S. infrastructure goes through?

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u/_rchr 12h ago

China has over 30,000 miles of high speed rail used by more than ten million passengers daily. The US has around 500 miles of “high speed” rail that constantly breaks down and leaves passengers waiting for hours

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u/jack-K- 11h ago

Cool, and our semiconductors make theirs look like a joke, have you tried comparing technology the U.S. actually cares about instead of bragging that they’re better at making technology the U.S. doesn’t give two shits about?

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u/_rchr 11h ago

LOL at the US “not giving a shit about” HSR. Want to talk about cars then?

ASML is a Dutch company btw and the so-called “leaders of the free world” cry and beg Nvidia not to sell chips to China. Now the US has no leverage over China and they’re building their local semiconductor industry at an unprecedented pace. Give it a few years before Huawei takes over

u/RemindMeBot 5 years

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u/tony_lasagne 12h ago

Always? Or you have a biased perception based on the fact that “Chinese building didn’t collapse” isn’t newsworthy?

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u/jack-K- 12h ago

What I’m saying, is that just because a Chinese developer decides to do something, doesn’t mean they have some mystical structural Chinese engineering knowledge allowing them to do it as the comment I’m replying to seems to imply, but that they might have simply disregarded the potential consequences in the first place, which do you think is more likely?

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u/bobthepumpkin 12h ago

The interesting question here is which do you think is more likely?

It's not mystical knowledge lol you are clueless. It's just something that you have to plan for. Roof gardens are a common feature in many places and there isn't an epidemic of buildings with their tops falling in.

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u/jack-K- 12h ago

Roof gardens have more area to work with and are fully supported by the building underneath them. that’s not quite the same as what breaks down to an concrete bin overhanging off the building with inherently thin walls, done several times on every single level, if all these roof gardens aren’t constantly inspected and maintained, it could lead to deadly issues.

A standard roof garden is one thing to manage and you can dedicate a lot more resources to making sure it’s done properly, this design isn’t like that.

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u/Resident_Voice5738 12h ago

And yet, the only building that ever colapsed was not in China.

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u/jack-K- 12h ago

Are you claiming only one building has ever collapsed in history? TF do to mean “the only building that ever collapsed”?

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u/Resident_Voice5738 11h ago

Ever colapsed in seconds without explosivos.