What happens when you install a suspension bridge without suspension?
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Here's looking at you Florida...
If you look at the planned design, and then what actually fell, it doesn't match. IT'S COMPLETELY MISSING THE SUSPENSION ELEMENTS!
I'm not a bridge engineer, but I'd sure like to know who had the bright idea of putting up what is essentially a double deck concrete bridge without the suspension going up FIRST. Even for 5 days.
Expecting that thing to stay up, even on a temporary pier, seems to me where the failure occurred.
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>I'm not a bridge engineer,
>I'm not a bridge engineer, but
yep
Top of Page Bottom of Page PermalinkFull Name: vivalavuvuzela
Seriousleee..... looking at
Seriousleee..... looking at what fell, I immediately said to myself how it looks way too heavy and long for a truss bridge... not the mention the asymmetrical design of the span that fell. When viewed by itself, it was essentially a truss bridge with irregular geometry.
Look at the plans... there is no pier directly under it in the middle... it shows a suspension tower right beside the deck. Instead it was left sitting on a pier roughly where the tower should be. (temporarily?)
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Waiting for Sideshow Bob to
Waiting for Sideshow Bob to weigh in here. Unfortunately, I think he's away at Panic in D.C... And look what happened!
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When I see them build a
When I see them build a bridge on one of those engineering marvels TV shows, they always build the suspension system before the roadway.
Top of Page Bottom of Page PermalinkFull Name: always
it will be a while before we
it will be a while before we know the EXACT thing that led to the failure yesterday.
from everything i have reviewed this section of slab looks to be post tension with the majority of the load coming from the design itself(dead load).
the suspension "look" is not suspension, it is exposed post-tension.
from what i have read, some of the rebar tension on the slab had fallen to below tolerance upon site inspection by the engineer, and they ordered it brought back to range.
upon correcting the tension the collapse happened. normal post tension concrete construction stuff.
maybe one of the steel tension bars failed, maybe some sort of concrete imperfection at the wrong spot couldnt handle the tension and started the problem.
we will know after the investigation.
this type of work normal for the construction type, and stopping traffic on Calle Ocho everytime a cable needs tensioning would be insane and not to standards construction mean for the type of product being aseembled.
shitty day for a lot of familys. shitty day for the city and FIU. shitty day for all the teams involved.
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>> Waiting for Sideshow Bob
>> Waiting for Sideshow Bob to weigh in here. Unfortunately, I think he's away at Panic in D.C... And look what happened!
LOL
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fuck, my mind wasnt
fuck, my mind wasnt coordinating with my fingers in a few cases up there.
whew
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Well Bob did warn us if he
Well Bob did warn us if he quit going to work people would die.
Top of Page Bottom of Page PermalinkFull Name: gypsy tailwind
Dude seems to have his hand
Dude seems to have his hand in everything.
Builder of Miami’s collapsed bridge has a strange connection to Paul Manafort.
https://www.rawstory.com/2018/03/builder-miamis-collapsed-bridge-strange...
Top of Page Bottom of Page PermalinkFull Name: vivalavuvuzela
Our resident heady civ
Our resident heady civ engineer hero (ret.) had this to say, along with "tell them I lost my login":
"It starts with lack of logic - a simple steel box truss would have served the purpose fine, & it's cookie cutter design, fabrication, installation, inspection. Whoever in charge wanted some sort of "signature" "monument" structure, thus this vastly over complicated design. Someone probably was on Facebook instead of making sure things were being done right. But that'll never happen. The argument for monumental structures happened with the new sf bay bridge, Arnie was, to his credit, against, but the hippies won & it cost $350 m more. Imagine how much earthquake reinforcement could have been done to routine bridges all over the bay area for that kinda change. Google "steel truss pedestrian bridges" & you'll see what simple thing could have been done at far less cost. We had same debate on "q" bridge in New Haven too.
Some airport terminal in France collapsed years ago. Not even wind or snow or earthquake, couldn't even hold itself up. Designed by some world class architect
Other thought is that the temporary support is designed by the contractor ("means & methods") & not the designer. Code organizations want to change that but no designer wants that kind of headache. Big issue with skyscraper cranes, there were several collapses in nyc in recent years
I still haven't read the details. I'd want to know contract format: design/build, construction manager, at risk, general contractor, or traditional design - bid - build. All have different org charts for resposibility."
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gravity
gravity wins
Top of Page Bottom of Page PermalinkFull Name: Zzzzzz
I'm not buying into generic
I'm not buying into generic looking bridges as the answer. Simple structural designs I agree with.....