Viaducts and bridges, as made in China
October 26, 2015 12:26 PM Subscribe
I don't think all bridges are made by the products of the Beijing Wowjoint Machinery Co, though. That's an FPP worthy name all by itself.
posted by ambrosen at 12:48 PM on October 26, 2015 [3 favorites]
posted by ambrosen at 12:48 PM on October 26, 2015 [3 favorites]
How do they join the precast spans? Big old bolts and screws? There's some kind of plating on the inner surface of the spans that suggests they've already had holes drilled in them.
posted by Kevin Street at 1:04 PM on October 26, 2015
posted by Kevin Street at 1:04 PM on October 26, 2015
That really is a hell of a name:
posted by phooky at 1:05 PM on October 26, 2015 [14 favorites]
Wowjoint, naming from a philosophic word jointed by Willing, Objectiveness and Winning, was created in 1996, and always focuses on innovation to specialize in solution, design, fabrication and service for bridge construction and railway work.Willing, Objectiveness and Winning is my new band name, law firm, and personal philosophy.
posted by phooky at 1:05 PM on October 26, 2015 [14 favorites]
If this is happening on every bridge and viaduct construction site in the world, it doesn't really make it less amazing. Not to my eyes, anyway.
posted by DirtyOldTown at 1:15 PM on October 26, 2015 [2 favorites]
posted by DirtyOldTown at 1:15 PM on October 26, 2015 [2 favorites]
To me the amazing part isn't the giant machine, it's that they put all the piers into place and get the tops of them lined up with millimeters of precision. If the piers are perfectly in place then dropping in segments is "easy".
posted by GuyZero at 1:18 PM on October 26, 2015 [2 favorites]
posted by GuyZero at 1:18 PM on October 26, 2015 [2 favorites]
It's not happening like that in the US, that's for damn sure—our infrastructure is crumbling before our eyes.
posted by infinitewindow at 1:19 PM on October 26, 2015
posted by infinitewindow at 1:19 PM on October 26, 2015
These machines built the Canada Line
heh, not the part I use. We had an open trench down Cambie for ages
posted by Hoopo at 1:34 PM on October 26, 2015 [2 favorites]
heh, not the part I use. We had an open trench down Cambie for ages
posted by Hoopo at 1:34 PM on October 26, 2015 [2 favorites]
They used this same technique to construct a few of the elevated portions of the DC Metro Silver Line. There were 3 of these machines slowly crawling across Northern Virginia for a few years.
The post-tensioned concrete segments of the bridge are actually held together by steel cables (which is what actually gives the structure its strength). The bridges built for the DC Metro actually used smaller segments that were attached one at a time, presumably because that allowed them to be fabricated offsite and moved into place by truck. The small segments were strong enough to hold their own weight between two spans, and it was pretty freaky to see the bridge segments precariously hanging in the air.
I'm not a structural engineer, but AFAIK, this technique has a few drawbacks, as it requires more steel and concrete than you'd otherwise need (and probably doesn't scale particularly well to a wide bridge like you'd want for a freeway).
The Vancouver SkyTrain was the first project to use this system extensively. It's a neat method if you have a big bridge to build, and can't easily get a crane or girder into place (read: it's probably overkill for a freeway overpass).
If you look at the above link, it looks like there are a huge number of bridges in the US that have been built using this method.
posted by schmod at 1:43 PM on October 26, 2015 [3 favorites]
The post-tensioned concrete segments of the bridge are actually held together by steel cables (which is what actually gives the structure its strength). The bridges built for the DC Metro actually used smaller segments that were attached one at a time, presumably because that allowed them to be fabricated offsite and moved into place by truck. The small segments were strong enough to hold their own weight between two spans, and it was pretty freaky to see the bridge segments precariously hanging in the air.
I'm not a structural engineer, but AFAIK, this technique has a few drawbacks, as it requires more steel and concrete than you'd otherwise need (and probably doesn't scale particularly well to a wide bridge like you'd want for a freeway).
The Vancouver SkyTrain was the first project to use this system extensively. It's a neat method if you have a big bridge to build, and can't easily get a crane or girder into place (read: it's probably overkill for a freeway overpass).
If you look at the above link, it looks like there are a huge number of bridges in the US that have been built using this method.
posted by schmod at 1:43 PM on October 26, 2015 [3 favorites]
Well, it took China thousands of years but they finally learned their lesson. They're making bridges, not building Walls.
posted by Joe in Australia at 2:59 PM on October 26, 2015 [2 favorites]
posted by Joe in Australia at 2:59 PM on October 26, 2015 [2 favorites]
I just sent two of these videos to my 13 year old son to remind him that cool stuff still gets built in not-minecraft.
posted by double block and bleed at 7:29 PM on October 26, 2015
posted by double block and bleed at 7:29 PM on October 26, 2015
Is there something about these machines that inspires such chirpy and overly-climactic music?
posted by sneebler at 7:32 PM on October 26, 2015
posted by sneebler at 7:32 PM on October 26, 2015
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posted by Keith Talent at 12:46 PM on October 26, 2015