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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

#41

Post by jessaustin »

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.

But FIU's bridge was designed to mimic the dramatic look of a cable-stayed bridge, where the deck is suspended from cables fanning out from a tall mast. In FIGG's design, though, the "cables" — actually metal pipes — were mostly just for show. The diagonal, v-shaped struts of the truss did the structural work.

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

#42

Post by steve_g »

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?

The families of the people that were killed want to understand what happened. Delays and silence will make their suffering worse.

People are often very forgiving when they know what actually happened. But being shut out of the information flow is a problem.

I'm not saying we need to find the guilty and punish them, but there are people that have a real stake in finding out the story.

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

#43

Post by jessaustin »

JauntyHatAngle wrote: post #29
jessaustin wrote: post #22

Earlier quoted context omitted.

The phrase "witch hunt" implies that society intends to persecute some low-status unfortunates on false pretexts. The politically-connected administration of some rich school built a giant bridge and within a week it fell down and killed some people. Investigating this incident is as far from the meaning of "witch hunt" as we might imagine.

I was using the term to imply someone (or some thing in the case of a company) being labelled as the villain without the evidence conclusively proving they are guilty of the crimes they are accused of.

Do you doubt that the bridge collapsed? Or do you expect that someone besides the engineer or builder will be blamed for the collapse?

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

#44

Post by crwalker »

beachy wrote: post #3

> But FIU's bridge was designed to mimic the dramatic look of a cable-stayed bridge, where the deck is suspended from cables fanning out from a tall mast. In FIGG's design, though, the "cables" — actually metal pipes — were mostly just for show. The diagonal, v-shaped struts of the truss did the structural work. I've always found it useful to hone in on anything that is done purely for aesthetic reasons. We build a h…

Yes! Good thing you pushed back on the architect.

I have a similar design philosophy that honesty is more aesthetically pleasing than deception.

When designers resort to faux materials and structures, the truth still tends to peek through, resulting in an 'uncanny valley' of forms. For example: * Brickwork veneers bend in the wrong spots * Faux beams are placed in the wrong locations with the wrong joints, announcing that they can't bear a load

There's certainly a place for decorative elements, just not decorative elements pretending to be something else.

I spent several summers framing houses, so I'm looking forward to an opportunity to design my own house - and maybe 3D printing it.

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

#45

Post by Mtinie »

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…

Static force analysis only works when the materials being modeled are well known. Titanium dioxide concrete is a novel material—and, from the article’s text and subsequent research—appears to have a narrow effective range before integrity issues appear.

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

#46

Post by crwalker »

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 suspect that a lot of our better skyscrapers will be around in 500 years: once a pattern is set, people like to preserve it.

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

#47

Post by fma »

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…

It always scares me that civil engineers and other real engineers (with professional engineer certificates) rely on software built by software "engineers" who may just be some kids out of high school that picked up coding.

It's an extreme scenario, yes, as I'm sure/hope the software goes through rigorous testing.

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

#48

Post by CtrlAltT5wpm »

ndespres wrote: post #19

> And in order to pull off the aesthetic, the bridge's designers had to make the diagonal supports beneath them a variety of different shapes and sizes. That complication may have led the designers to miss a crucial error, independent engineers who've examined the bridge's plans believe: One of the supports was not strong enough. They aren't joking about the "variety of different shapes and sizes" for the diagonal su…

> Why is the campus divided by a highway to begin with?? But that's neither here nor there.

That's probably more circumstance than anything else. The area immediately north of the campus has a lot of residential housing, attractive to both students and employees, moreso because Miami's public transit is gawdawful; if you can walk to school/work, avoiding the traffic, that's a bonus.

Additionally, the campus wasn't always the behemoth it is now. The highway they speak of is SW 8th Street, or Tamiami Trail, if memory serves. It's a main road in the area The campus was always adjacent, but only semi-recently has it begun to truly crowd the road, likely a byproduct of all the insane construction going on in the school. FIU is far from the only school spending ridiculous money on infrastructure. The school was never really plopped down next to a major highway...they both just grew, and city planning has never been the area's strong point.

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

#49

Post by jfoutz »

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…

Also it looks taller, same reasons people prefer vertical stripes to horizontal stripes. Pinstripes, corduroy, stuff like that take advantage of the same effect.

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

#50

Post by echotango »

subjectsigma wrote: post #33
RcouF1uZ4gsC wrote: post #12

Earlier quoted context omitted.

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 inspirat…

I agree, it is beautiful. But Ayn Rand would have hated it. That design is steeped in European and Christian traditions and symbolism. Those things are all anathema to her ideology.
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