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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

#91

Post by stevenwoo »

RcouF1uZ4gsC wrote: post #14

> At least one said that if so, it constitutes an avoidable mistake on a bridge that should never have been so complicated. >“This is not a big project," Beck said. "It’s a darn pedestrian bridge.” There is something to be said about not over-complicating designs, whether it be in actual construction or in software.

They had many similar goals for a pedestrian bridge in California around 2008 or so, but they chose steel instead of concrete, a properly engineered concrete one got much more expensive bids. It's always kind of weirdly delightful to go home from a trip out of town and pass under it on I-280.

https://en.wikipedia.org/wiki/Don_Burnett_Bicycle-Pedestrian...

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

#92

Post by angersock »

elefanten wrote: post #77
bsder wrote: post #71

Earlier quoted context omitted.

> It bugs me that FIGG (one of the contractors) appears to be threatening the professional licenses of the engineers who helped the Miami Herald's investigation, by suggesting that doing so was unethical. As a licensed Professional Engineer, you have to be quite careful criticizing other engineers. As long as the engineer signing off met "standard practices", he is covered and saying that he is not could get you in q…

Can you elaborate? This seems like a very perverse system. Why is criticism viewed to be so dangerous? As long as both the critic and the criticized are supporting their arguments with reasons and engaged in dialogue, the outcome should be net good for everyone.

> Why is criticism viewed to be so dangerous?

Criticism, behind closed doors or strictly in the company of other engineers with the correct training and experience, is not dangerous.

Criticism shared with non-engineers amounts to second-guessing and degrades the trust of the public in the profession as a whole, which has tangible negative outcomes for everyone.

Imagine if every project you'd been on had another developer bending the ear of management saying "oh, that's the wrong editor...oh, that's not the right algorithm to use..."! It'd be awful.

For mechanical and structural engineering, both much more difficult and unknowable than software, it is of the utmost importance not to foment doubt and uncertainty in people who are by definition unqualified to properly understand the criticisms and weight them.

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

#93

Post by [deleted] »

ceejayoz wrote: post #23

> "This structure should function as more than just a path for circulation; it should be a place to be and a place to be experienced, and the FIU campus and its students must be proud of it," the document's introduction reads. "It should be a destination in its own right where community members might linger, gather, and create an urban social space — a linear park." This reads a lot like every startup that tries to c…

[deleted]

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

#94

Post by WalterBright »

antod wrote: post #82
hinkley wrote: post #35

Earlier quoted context omitted.

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?

Not necessarily. Static analysis means a specific thing in structural engineering. Pin jointed frames with diagonal members (eg trusses) are easy to analyse with just geometry (statically determinate). But moment resisting frames without diagonals are not statically determinate and require more iterative calculations (usually computer modelled these days). Doesn't mean you shouldn't build them though.

Doing a pin joint frame static analysis is simple, and will yield a lower bound on the loads on the struts. It would serve as a good cross check on the computer model.

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

#95

Post by ajdlinux »

JauntyHatAngle wrote: post #36
danso wrote: post #20

Earlier quoted context omitted.

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 bec…

> 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?

I'd suggest that it's not an issue of bad faith regarding the NTSB, but rather that the NTSB doesn't (and shouldn't!) care about the political fallout from this, whereas a newspaper very much has an interest in uncovering the political side of this.

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

#96

Post by abduhl »

bsder wrote: post #71
mannykannot wrote: post #64

It is heartrending to realize that they were given one last chance to step back from the abyss, when cracks appeared, but they pressed on regardless. If something happens that you don't understand, it's time to halt and reevaluate. It bugs me that FIGG (one of the contractors) appears to be threatening the professional licenses of the engineers who helped the Miami Herald's investigation, by suggesting that doing so…

> It bugs me that FIGG (one of the contractors) appears to be threatening the professional licenses of the engineers who helped the Miami Herald's investigation, by suggesting that doing so was unethical. As a licensed Professional Engineer, you have to be quite careful criticizing other engineers. As long as the engineer signing off met "standard practices", he is covered and saying that he is not could get you in q…

I'm unaware of any liability that can be picked up through rendering an opinion on a design. I have participated in forensic engineering / expert witness cases in geostructural matters. In fact, the opinion of an engineer as an "expert witness" is often codified in law as retaining no liability. Asking questions and drawing conclusions is not something that presents any risks besides you being possibly proven wrong later. If you don't stamp the design to be constructed, then there is no liability.

I would be very interested in any law or regulation you can find that says otherwise.

I would also add that most of the involvement of engineers during lawsuits is to establish exactly what state of practice is in the local area. It would be hard to do that if all these other engineers didn't have or couldn't give an opinion.

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

#97

Post by jnwatson »

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'.

Well, there is a root cause. There are possible contributing factors, yes, but the root cause, according to the article, was incorrect calculations that lead to the underspecification of truss 11.

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

#98

Post by peterwwillis »

mygo wrote: post #39
peterwwillis wrote: post #18

Earlier quoted context omitted.

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 diff…

I'm not in disagreement with you, but there is another aspect to consider.

In the case of many of these structures, their physical form is a reflection of some spiritual aspect. They're basically religious icons. Their design may be carried forward in part just because not doing so would be disrespectful on a spiritual level, or because they remind people of something. But they're not all the same.

There are probably thousands of different torii gates with slightly different designs. Some show an extended nuki with kusabi wedges, a modified mortise and tenon style joinery. But many torii gates don't feature these. Nuki joints are actually widely used as ornamental carpentry, and can be found in several non-wooden objects.

The construction of most torii, regardless of their material, seems to be about aesthetics (and honoring whoever paid to put it up) before the rest.

If you want maximum accomplishment with a material, check out their multi story pagodas that use a massive wooden beam in the middle. It acts as a mass damper and prevents the different floors from sliding off the building during an earthquake, as they aren't attached to each other. Hard to do that with stone! :)

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

#99

Post by tankerslay »

angersock wrote: post #92
elefanten wrote: post #77

Earlier quoted context omitted.

Can you elaborate? This seems like a very perverse system. Why is criticism viewed to be so dangerous? As long as both the critic and the criticized are supporting their arguments with reasons and engaged in dialogue, the outcome should be net good for everyone.

> Why is criticism viewed to be so dangerous? Criticism, behind closed doors or strictly in the company of other engineers with the correct training and experience, is not dangerous. Criticism shared with non-engineers amounts to second-guessing and degrades the trust of the public in the profession as a whole, which has tangible negative outcomes for everyone. Imagine if every project you'd been on had another devel…

"Scandal" should be avoided because it "degrades the trust of the public in the profession." An age-old saw trotted out to justify the cover-up of diverse kinds of negligence and malfeasance in all manner of professions the world over.

It works precisely until there is a scandal too big to cover-up.

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

#100

Post by TeMPOraL »

paulie_a wrote: post #78
fma wrote: post #47

Earlier quoted context omitted.

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.

When I was growing up I lived in a small town and the city planner had mocked the entire town in the original SimCity. The ongoing joke was that he would test any proposals in that.

At least you had a city planner.

The city I grew up in is a larger one, and currently seems to be entirely in the hands of private developers - who just dump closed-off groups of blocks at random throughout the city, hoping to sell the apartments, without any consideration to things like neighborhood, surrounding architecture or road throughput.

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