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FIU had grand plans for 'signature' bridge. But the design had a key mistake

miamiherald.com

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Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#31

Post by Shank »

JauntyHatAngle wrote: post #16
Shank wrote: post #11

Earlier quoted context omitted.

I concur on the quality of the article, but I would say it goes further: The Miami Herald is even suing to get public records requests filled in the interest of journalism. They’re doing an exceedingly good job at trying to get answers to tough questions.

I am ignorant as to this whole story, but out of interest, why is it a bad thing to wait for the NTSB report? Often it is good to wait for an entire report to nail down the facts before the witch hunt should begin, is there something in this case that means this isn't the best idea?

Personally, I don’t think that waiting for the NTSB determination is a bad thing. However, I do believe there’s a problem with suppression of public record so that, in effect, a single agency can control the statement that comes out.

To be clear, I fully trust the NTSB. It’s more that I want to make sure that there are checks and balances — even when a just agency is doing the reporting. It adds another protection layer to the system.

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#32

Post by scarejunba »

Maybe this will put paid to the nonsense people constantly spout about "real engineering". Turns out doing new things is hard.

But also let's be real, you're not going to cross a 10-lane stroad, bridge or no bridge and feel like you're in 'a college town'. It was never gonna happen.

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#33

Post by subjectsigma »

RcouF1uZ4gsC wrote: post #12
lrn wrote: post #9

The Fountainhead Chapter I; Howard Roark to the Dean --- "Why do you want me to think that this is great architecture?" He pointed to the picture of the Parthenon. "That," said the Dean, "is the Parthenon!" "So it is." "I haven't the time to waste on silly questions." "All right, then." Roark got up, he took a long ruler from the desk, he walked to the picture. "Shall I tell you what's rotten about it?" "It’s the Par…

Then again the Parthenon has has been around for nearly 2,500 years (finished in 432 BC), and during that time has been considered by people from all over the world one of the most beautiful buildings ever built. What building by modern architects will even be around 500 years from now, much less revered as an example of beautiful architecture?

I can see La Sagrada Familia not only being around, but being celebrated, for 500 years more. It's still under construction and has been for (almost?) 100 years. Google it, the church is absolutely beautiful.

In fitting with the theme of the GP, not only is it structurally sound (to my knowledge) because of how the pillars are constructed, but it successfully pays homage to Gothic architecture and the oldest inspiration, Nature, while also being new and innovative.

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#34

Post by yardie »

peterwwillis wrote: post #25

So many concrete bridges fail for so many reasons, it's kind of crazy that we keep building them. It's much easier to inspect and repair steel than concrete, and it fails more gracefully. Also, I'm not even an engineer and I can tell you that uneven strut design would give you uneven loading on the span. Christ. Why didn't they just build a damn cable stayed bridge?! If traffic was a concern, they could have built it…

It was a cable stayed bridge. The bridge span was just put up. The tower and the cables were to be installed over the next few weeks. They allowed traffic under an incomplete bridge because money.

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#35

Post by hinkley »

WalterBright wrote: post #28

"But they suggested that over-reliance on the computer models, a common pitfall in the profession, may have played into it." It's very easy to be seduced into assuming a computer model's results are correct. Computer models of critical bits should always be double-checked by a separate independent calculation. For this bridge, a simple analysis of static forces should have been sufficient for a cross-check, despite t…

If you did find a way to design a structure so that analysis of the static forces was not straightforward, might that be a good indication that you shouldn’t build it at all?

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#36

Post by JauntyHatAngle »

danso wrote: post #20
JauntyHatAngle wrote: post #16

Earlier quoted context omitted.

I am ignorant as to this whole story, but out of interest, why is it a bad thing to wait for the NTSB report? Often it is good to wait for an entire report to nail down the facts before the witch hunt should begin, is there something in this case that means this isn't the best idea?

I imagine the Herald doesn't believe that the NTSB (or any authority) necessarily has the canonical and final word on things, and thus the Herald sees itself as providing an independent viewpoint/assessment. One of the undercurrent themes of this story is that, according to the herald, the construction company and FIU officials are well-connected politically. Possibly related to this is the fact that the Herald is su…

So the prevailing thought is that the NTSB is delaying the documents to protect FIU officials, and not to prevent undue influence of the public before the release of the report?

It certainly doesn't look good from this quoted paragraph...

"Public records made and received by the Department from February 20 until the bridge collapsed on March 15 obviously were not obtained by the Department during an investigation because there had been no accident, much less an investigation into an accident,'' he wrote in a response to the FDOT motion to dismiss the lawsuit.

"Florida law is clear that if an agency’s record is a public record at the time it is made or received, then that document does not lose its character as a public record if the document is later given to an investigative agency in the course of a subsequently initiated investigation."

Still could be to prevent a public outcry before the facts are in, but that does seem mighty fishy...

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#37

Post by tialaramex »

Shank wrote: post #11
cagenut wrote: post #6

This is a really good article. Amazing how a dozen+ different things combined to produce the unfortunate result. Perfect case study in there being no such thing as a singular 'root cause'.

I concur on the quality of the article, but I would say it goes further: The Miami Herald is even suing to get public records requests filled in the interest of journalism. They’re doing an exceedingly good job at trying to get answers to tough questions.

There already exists an entity with the actual purpose of getting answers to those tough questions, which is in fact already doing so, the NTSB.

The Miami Herald is suing to get more material so that it can run more speculative headlines, which doubtless is great for the Miami Herald, because it drives revenue from selling papers and from advertising. But unlike the NTSB the Miami Herald has no real interest in the prevention of future harm.

Accident investigators like the NTSB need legal protection so that they get honest answers, in the service of the prevention of future harm. The harder you make it for them to do that job, the less effective they are.

There's often a fantasy in play in which people suppose that surely if everything was out in the open we'd fix all these problems, wouldn't we? But we've actually run that experiment already and the results were not good. Without the methodical independent investigation big vested interests are able to direct the narrative as they choose. And their interest isn't preventing future harm... except to themselves. So nothing improves, you will read the same stories, and be pointed at the same scapegoats, forever.

The specific focus on _preventing future harm_ is what's important about accident investigators. You might think a court seems like the right place, but courts are about _justice_ which isn't interested in future harm at all. Here's a nice modern British example that shows this difference:

A young woman drunkenly leans against a train as it departs, to the horror of those inside the train she falls and is killed.

The accident investigators look at that and their concern is: How should we prevent similar things happening? They look at lots of evidence as to exactly what happened and when, they interview people, they review the technology in place, and they make recommendations for how we can prevent the same tragedy re-occurring.

The court says: The train guard has a legal responsibility towards passengers, the evidence shows he did not do everything by the book, and a passenger died. If you have a legal responsibility but you don't do things by the book and someone dies, that's manslaughter. Guilty. Prison.

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#38

Post by [deleted] »

yardie wrote: post #34
peterwwillis wrote: post #25

So many concrete bridges fail for so many reasons, it's kind of crazy that we keep building them. It's much easier to inspect and repair steel than concrete, and it fails more gracefully. Also, I'm not even an engineer and I can tell you that uneven strut design would give you uneven loading on the span. Christ. Why didn't they just build a damn cable stayed bridge?! If traffic was a concern, they could have built it…

It was a cable stayed bridge. The bridge span was just put up. The tower and the cables were to be installed over the next few weeks. They allowed traffic under an incomplete bridge because money.

[deleted]

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#39

Post by mygo »

peterwwillis wrote: post #18
lrn wrote: post #9

The Fountainhead Chapter I; Howard Roark to the Dean --- "Why do you want me to think that this is great architecture?" He pointed to the picture of the Parthenon. "That," said the Dean, "is the Parthenon!" "So it is." "I haven't the time to waste on silly questions." "All right, then." Roark got up, he took a long ruler from the desk, he walked to the picture. "Shall I tell you what's rotten about it?" "It’s the Par…

This isn't the only example of that. Imitating an archaic form of architecture is often a homage. Go to some modern temples/shrines in Japan. Check out the torii gates and any other classical looking structure. Compare the ones in wood to the ones in stone or concrete. They look identical. If you look close, you'll notice the little details sticking out of parts of the design. It's almost always a part of Japanese wo…

Is the goal to make beautiful structures, or is it to make beautiful structures as if they still have the characteristics of wood?

I’m inclined to believe that, if the original masterful wood-crafters had instead began their professions with stone, that they would have created beautiful structures that fully explored the capabilities of stone, and that their contributions to architecture may have looked a little different, but no less aesthetic.

So, assuming the will of the original craftsmen was to simply make the most aesthetic structures that their materials would allow (and maybe I’m wrong about that), would it be paying homage to them by making stone copies of their wooden accomplishments while working in a new medium with different characteristics, or would it be paying homage to them by continuing their pursuit and fully exploring the capabilities of stone, as the forefathers had done with wood?

That’s a question with no right answer... but I personally believe that homage is not to copy one’s output, but to copy one’s input.. To seek what they sought. To do as they would have done if they had stone instead of wood.

Re: FIU had grand plans for 'signature' bridge. But the design had a key mistake

#40

Post by hrunt »

yardie wrote: post #34
peterwwillis wrote: post #25

So many concrete bridges fail for so many reasons, it's kind of crazy that we keep building them. It's much easier to inspect and repair steel than concrete, and it fails more gracefully. Also, I'm not even an engineer and I can tell you that uneven strut design would give you uneven loading on the span. Christ. Why didn't they just build a damn cable stayed bridge?! If traffic was a concern, they could have built it…

It was a cable stayed bridge. The bridge span was just put up. The tower and the cables were to be installed over the next few weeks. They allowed traffic under an incomplete bridge because money.

It specifically was NOT a cable-stayed bridge. It was a non-redundant truss bridge with a tower and faux stays that contributed nothing to the structural capabilities of the bridge. The arrangement of the truss structure mimiced the stay angles purely for aesthetics, not for any other reason. The choice to use a single truss structure rather than a more traditional redundant set of trusses was due to the desire for a striking design.

Adding the tower or cables would have done nothing to strengthen the bridge. The engineers in the article suggest that the second shorter section of the bridge to be built afterwards may have alleviated some of the stresses on the north truss beam, but the truss itself was unorthodox, so they cannot say anything for certain.

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