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and never look down the aisle of an airplane while it's taking off or landing.
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# ? Dec 12, 2014 06:13 |
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# ? May 29, 2024 14:43 |
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Slim Pickens posted:The way it slides backwards, I think he's trying to gun it uphill as well. Is this dude fresh from California or something? no. He's from the south.
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# ? Dec 12, 2014 06:44 |
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EightBit posted:Try not to notice skyscrapers slowly moving back and forth now that I've told you about it. One of the guys I talk to all the time works in one of the higher floors of a skyscraper in NYC, and has an inclinometer mounted on his wall. He will gleefully tell anyone who asks about it what it is, and what the readings mean. I guess some people are cool with it, and others freak right the gently caress out.
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# ? Dec 12, 2014 07:25 |
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Powershift posted:and never look down the aisle of an airplane while it's taking off or landing. Never noticed that but I enjoy watching the wings flex. This isn't something to point out if you're flying with someone who is afraid of flying.
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# ? Dec 12, 2014 11:40 |
People are funny. They'll fly or work in skyscrapers their whole lives, never hearing of an incident where a skyscraper fell the gently caress over or a plane flexed in half during takeoff; but show them evidence of slight movement (that is carefully designed in) and all of a sudden they think it's totally unsafe and THEY PERSONALLY must never do X again.
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# ? Dec 12, 2014 13:37 |
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Data Graham posted:People are funny. They'll fly or work in skyscrapers their whole lives, never hearing of an incident where a skyscraper fell the gently caress over or a plane flexed in half during takeoff; but show them evidence of slight movement (that is carefully designed in) and all of a sudden they think it's totally unsafe and THEY PERSONALLY must never do X again. https://www.youtube.com/watch?v=rak2HldVp9M
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# ? Dec 12, 2014 14:03 |
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Sitting near the back of an A340 on takeoff is certainly an experience, the whole fuselage hogs from the wing spar as you climb away. The skyscraper inclinometer is genius, if I ever end up working in one I know what I'm putting on the wall first.
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# ? Dec 12, 2014 14:36 |
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I was downtown at an event when Ike rolled through town and we had 75mph winds. I'm standing directly underneath the largest towers in the city and watching them sway a good 4-5 feet back and forth above me. It was terrifying. Then I get home and turn on the news and that same building had been shedding parts from the top pretty much right onto the area I had been at.
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# ? Dec 12, 2014 15:47 |
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revmoo posted:I was downtown at an event when Ike rolled through town and we had 75mph winds. I'm standing directly underneath the largest towers in the city and watching them sway a good 4-5 feet back and forth above me. It was terrifying. Then I get home and turn on the news and that same building had been shedding parts from the top pretty much right onto the area I had been at.
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# ? Dec 12, 2014 16:32 |
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My wife works in the Prudential tower in Boston and she says you can definitely feel the building sway in the wind.
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# ? Dec 12, 2014 16:32 |
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Just google for skyscrapers during earthquakes for some But those are probably mechanical successes.
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# ? Dec 12, 2014 16:41 |
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I am a huge fan of the Citicorp Center story. http://www.slate.com/blogs/the_eye/2014/04/17/the_citicorp_tower_design_flaw_that_could_have_wiped_out_the_skyscraper.html https://www.youtube.com/watch?v=TZhgTewKhTQ Effectively, this chap who designed it built the building onto almost 'stilts' to leave the ground level area around the building less occupied by, well, building, which would (in architect terms) integrate the slab-sided monolith into its surroundings and become a part of civic unity and pride as New Yorkers of all stripes would meet beneath its capacious skirt. Since it was very light, it would sway more in the wind than conventional rival skyscrapers, so they added one of the first tuned inertial mass dampers to the building in order to keep the building stable. Building gets made, everyone is super happy, champagne and handshakes all around. Chief structural engineer gets a phone call from an undergrad student who says her prof claims that the building will fall over, and asks if her prof is full of poo poo. Chief structural engineer says, sure, your prof is full of poo poo. Life goes on. Chief structural engineer starts to think. Goes back to the notes. Realizes that accounting for stress was only done on perpendicular winds (north/west/east/south, on slab sides of the building) but not on quartering winds (e.g. northwest). Usually perpendicular winds are the biggest loads on conventional buildings, but this isn't a conventional building. He goes and figures out (with the help of some friendly Canadians) how much of a load it would take to knock the building over, figures out that actually it's like a 1 in 55 years' storm. Realizes that a blackout, which usually happens in a storm, will prevent the tuned inertial mass damper from working. Realizes that without the damper you only need a 1 in 16 years' storm and this poo poo is taking out Lower Manhattan. Realizes that that storm is coming very soon - hurricane Ella. To his credit, he raises the alarm and everyone worked together to make sure that the building gets repaired. The problem was that they substituted bolts for welds and ended up having to tear up every structural bolt (inside a populated office, working evenings and weekends) and replace them with welded-on brace plates. The New Yorker story goes into a lot more detail. It's a feel-good engineering story: someone notices a problem even when it's expensive to fix it, everyone does the right thing and nothing bad happens. Seat Safety Switch fucked around with this message at 16:50 on Dec 12, 2014 |
# ? Dec 12, 2014 16:46 |
That's an awesome story. And all you have to do is glance at the stilts layout and you realize how it's the quartering winds you have to worry about, whereas in every other building they're a non-issue if you've built it for perpendicular ones. Guy was too close to his work to step back and question first principles. E: Also "doing the right thing" is an interesting call to make, considering that what they did was perform all the shoring-up welding in secret, without informing the Citicorp employees. Data Graham fucked around with this message at 17:15 on Dec 12, 2014 |
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# ? Dec 12, 2014 17:11 |
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Well at least it could be fixed by upgrading fasteners, that's pretty impressive to me. I imagine the owner was not happy about the additional cost.
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# ? Dec 12, 2014 17:15 |
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Data Graham posted:E: Also "doing the right thing" is an interesting call to make, considering that what they did was perform all the shoring-up welding in secret, without informing the Citicorp employees. Or anyone, after the fact. The hurricane didn't make landfall? Oh well no harm done, life goes on. Wonder how big the lawsuits were.
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# ? Dec 12, 2014 17:17 |
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xzzy posted:Well at least it could be fixed by upgrading fasteners, that's pretty impressive to me. To be fair, if I remember the story right, the welds are what he had specified originally in his design. The bolts were a later change that normally would've been fine.
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# ? Dec 12, 2014 17:24 |
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Shampoo posted:My wife works in the Prudential tower in Boston and she says you can definitely feel the building sway in the wind. I work in the Sears Tower, on the 39th floor. I've got a friend up in the 90s. On windy days, he goes downstairs to use the toilet, because toilet water can slosh out. I can't feel the building actively swaying where I am, but I can absolutely feel the structure vibrating with the movement. The bathrooms and conference rooms close to the building's core sound like a movie pirate ship creaking back and forth.
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# ? Dec 12, 2014 17:59 |
Does everyone refuse to start calling it the Willis Tower?
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# ? Dec 12, 2014 18:00 |
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I recommend listening to the podcast linked from the Slate article: https://soundcloud.com/roman-mars/99-invisible-110-structural-integrity The first 14 minutes or so are covering the same story as most of the articles, beyond that point they located the student who got the ball rolling and had her tell her side of it. xzzy posted:I imagine the owner was not happy about the additional cost. The podcast has a clip from a lecture by the engineer where he mentions that the cost estimate on the fix was only a million or two. I'd imagine when your $195 million building is basically guaranteed to not only fail but level a good chunk of Manhattan in the process that's the kind of number you hope for as opposed to tens or hundreds of millions.
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# ? Dec 12, 2014 18:04 |
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wolrah posted:The podcast has a clip from a lecture by the engineer where he mentions that the cost estimate on the fix was only a million or two. I'd imagine when your $195 million building is basically guaranteed to not only fail but level a good chunk of Manhattan in the process that's the kind of number you hope for as opposed to tens or hundreds of millions. They also probably spread that cost out over a decade or so, versus a one time chunk payment.
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# ? Dec 12, 2014 18:04 |
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I moved up here a year and a half ago, and called it the Willis Tower once. Three people yelled at me. If I'm talking to taxi drivers, I'll say "Willis Tower, you know, Sears Tower". If they've been here a while, they'll know the latter. If they haven't, they'll know the former.
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# ? Dec 12, 2014 18:05 |
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It's the Sears Tower, it'll be the Sears Tower until no one's alive who remembers that's what it was once was. Little kids will sit on their grandpa's knee and look up with huge saucer eyes, "grandpa, what's a Sears?"
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# ? Dec 12, 2014 18:11 |
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See also: Sears Point Raceway. (What is it with Sears anyway.)
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# ? Dec 12, 2014 18:14 |
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xzzy posted:Little kids will sit on their grandpa's knee and look up with huge saucer eyes, "grandpa, what's a Sears?" You mean, kids today? Post Pictures of Horrible
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# ? Dec 12, 2014 18:16 |
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Safety Dance posted:I work in the Sears Tower, on the 39th floor. I've got a friend up in the 90s. On windy days, he goes downstairs to use the toilet, because toilet water can slosh out. I can't feel the building actively swaying where I am, but I can absolutely feel the structure vibrating with the movement. The bathrooms and conference rooms close to the building's core sound like a movie pirate ship creaking back and forth. Jesus, gently caress that. Would never work in something like that.
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# ? Dec 12, 2014 18:31 |
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BlackMK4 posted:Jesus, gently caress that. Would never work in something like that. You get used to it real fast. When I first moved up here, I was working out of a retrofitted factory that was up against an active rail line. Whenever a train would go past, the building would vibrate. It took me about a month to stop jumping out of my chair whenever that happened.
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# ? Dec 12, 2014 18:58 |
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wolrah posted:The podcast has a clip from a lecture by the engineer where he mentions that the cost estimate on the fix was only a million or two. I'd imagine when your $195 million building is basically guaranteed to not only fail but level a good chunk of Manhattan in the process that's the kind of number you hope for as opposed to tens or hundreds of millions. I'd be more curious as to why the building owner footed the bill instead of the engineering firm that didn't consider this to be a problem before committing the design to construction.
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# ? Dec 12, 2014 19:31 |
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Geoj posted:I'd be more curious as to why the building owner footed the bill instead of the engineering firm that didn't consider this to be a problem before committing the design to construction.
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# ? Dec 12, 2014 19:35 |
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BlackMK4 posted:Jesus, gently caress that. Would never work in something like that. I worked in an old three-story building and every time a car would drive past the front of the building the entire floor would shake rather strongly, doubly so for trucks and busses. I no longer work there but I wouldn't be surprised if one day it turns out to be a huge sinkhole or something.
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# ? Dec 12, 2014 19:36 |
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Geoj posted:I'd be more curious as to why the building owner footed the bill instead of the engineering firm that didn't consider this to be a problem before committing the design to construction. IOC mentioned the design firm likely had welds in the plans, then the construction firm substituted them with bolts which would be fine on a normal tower.
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# ? Dec 12, 2014 19:51 |
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Collateral Damage posted:Looking up wing flex tests on YouTube is interesting. Airliner wings are incredibly flexible. I don't think boeing posted a video of the full wing test for the 787 but it bent so far that it didn't even break while still surpassing the 150% max load margin. quote:During the test, the wings on the 787 were flexed upward “approximately 25 feet” which equates to 150 percent of the most extreme forces the airplane is ever expected to encounter during normal operation. The test is used to demonstrate a safety margin for the design and is part of the certification process to show the airplane can withstand extreme forces.
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# ? Dec 12, 2014 20:15 |
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Alighieri posted:IOC mentioned the design firm likely had welds in the plans, then the construction firm substituted them with bolts which would be fine on a normal tower. In which case either the construction firm is at fault for not green-lighting replacing the welds with bolts with the engineers, or else the engineering firm is back at fault for approving the substitution without considering the effects of indirect winds on the building. Considering they didn't even stop to think about the indirect wind issue until it was brought to their attention by an undergraduate student I'd guess its the latter...
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# ? Dec 12, 2014 20:29 |
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I re-read the article, and it would be the latter. The firm green-lit it but they didn't wait for (or even put it in front of) the original designer. A lot of it seems to come down to the fact that city code says "factor for perpendicular winds" so when it passes that test, nobody (other than the grad student) thought to see what would happen at angles.
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# ? Dec 12, 2014 20:36 |
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jammyozzy posted:See also: Sears Point Raceway. Sears Point Raceway (the correct name) is named after Sears Point, an actual point, which is named after some other dude named Sears
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# ? Dec 13, 2014 21:28 |
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It used to be called Sears Point Raceway, then Infineon Raceway and now is called Sonoma Raceway. http://en.wikipedia.org/wiki/Sears_Point
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# ? Dec 13, 2014 23:55 |
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Hell, I'm still uncomfortable with the idea of only eight planets and one Germany.
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# ? Dec 14, 2014 00:01 |
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Hermaphrodite posted:It used to be called Sears Point Raceway, then Infineon Raceway and now is called Sonoma Raceway. http://en.wikipedia.org/wiki/Sears_Point No, it is just sears point. All other names are wrong.
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# ? Dec 14, 2014 00:15 |
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Safety Dance posted:You get used to it real fast. When I first moved up here, I was working out of a retrofitted factory that was up against an active rail line. Whenever a train would go past, the building would vibrate. It took me about a month to stop jumping out of my chair whenever that happened. I have lived here my whole life. I went up the sears tower once....when it moved a little I immediately glued myself to the wall and didn't move till an elevator came to free me from my nightmare... yeah I cant do heights but growing up by a train yard I may or may have not gotten close enough to touch a moving train...But gently caress HEIGHTS AND BUILDINGS THAT MOVE WHEN YOUR IN THEM..... like the old folks home in my town that is the tallest building. the top floors feel like being on a ship
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# ? Dec 14, 2014 02:34 |
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Yeah a 1 story building rumbling when trains go by is not even comparable to a 90 story one where the water in the toilets sloshes around at the top. That's loving disturbing.
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# ? Dec 14, 2014 04:02 |
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# ? May 29, 2024 14:43 |
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totalnewbie posted:Just google for skyscrapers during earthquakes for some Ugh, the thought of being I a skyscraper during an earthquake does not sit well. Having been in an 8.0 earthquake on the second story of a two story building was bad enough to make we want to stay on the ground floor anywhere I go. Granted being in a skyscraper is likely a much safer place to be as long as your furniture stays put (and you).
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# ? Dec 14, 2014 04:36 |