The FIU Bridge Collapse – small dead animals

Language advisory.

12 Replies to “The FIU Bridge Collapse”

All bridges need a new warming informing possible users or pedestrians of gender of bridge designer.

AvE’s videhos should be required viewing in high school shop classes

Idiocracy.

Well this explanation is considerably better than the useless crap written by that clown expert a few days ago. They have definitely zoomed into the are where the bridge actually collapsed. But it is still drive by engineering.
Humorous explanation by the commentator. But still mostly speculation, which he did acknowledge towards the end of the video.
It will be at least a month before the non committal preliminary report is made, and another six months minimum before the final. Tedious work.

I’m not a video person I prefer reading, however I thought I would give it s try. I’m not a prude by any means and have heard lots of profanity during my 64 years. However to state what he stated and basically say if you don’t like the language the f*** off, I decided I had better things to do.

AvE is a national treasure. You can indeed go service your toque if you cannot handle shop language.
Thanks for reading. Keep your Richard in a bad habit!

I’m with you Mike. I skipped forwards a few times trying to get to the meat of the argument, and kept hitting swearing breaks. If the video didn’t have the swearing it probably would have run about 5 minutes in length and I actually would have watched it.
I’m trying to raise my kids to be civil and polite, and to save the profanity for when something is really, truly bad/important. If you say the same thing when you hit your thumb with a hammer as you do when you order coffee, does the word have a meaning to you anymore?

Precis for you pure types who can’t manage the bad language:
1: brittle failure points to broken tension bars. There’s a nice picture of a broken one with the hydraulic tensioner still on it.
2: evidence that the bridge movement plan was changed, over-stressing the tension bars.
3: evidence they were fiddling with the bridge while traffic was using the road.
4: evidence from on-site reports that people heard the tension bars snap before the bridge fell.
You’re welcome.
Taken together, this looks bad for a bunch of people who should have f-ing well known better, particularly the installing engineer who managed to miss all the warning signs, which included cracking of the deck and noises that are reported to have sounded like gunshots or whips cracking.

Nice summary. The foul language didn’t put me off as much as the choppy narrative. However, I surmise I am listening to a shop steward with years and multiple projects worth of experience … so I watched the whole video. He takes a long way around to explain (most likely) precisely what happened … although I love his toys (like hydraulic tensioner).
If this structure calculated to self support absent the tower and cable stays … then why was the tower and cable stays even necessary? This whole project appears to have been a politically-correct exercise in lieu of a responsibly engineered (and constructed) structure. And IF this Bridge was sooooooo innovative and “experimental” … then why use live humans as crash test dummies for your engineering experiment?
This truss section was fabricated in-place, perpendicular to the road. How is it possible that the truss section was not already properly tensioned before it was moved? How was it not released from all intermediate supports (while perpendicular to the road) to test and prove its structural integrity … BEFORE moving it over live human beings!? And just as a reminder … concrete takes (a minimum) of 28 days to fully cure to maximim compressive strength. Each concrete pour requires multiple test cylinders to taken, and crush tested at; 7, 14, and 28 days. Further, I expect this was HIGH STRENGTH concrete >6,000 psi. The mix, the timing of placement, and proper vibration is essential for developing full strength. After seeing the tensioning rod … intact … hanging out of the concrete web … I suspect the concrete failed.
However … this whole bridge design and construction sequencing seems convoluted and risky … why? To be some “demonstration” project for a bridge to Social Justice Engineering? This whole project reeks of false vanity and poseuring. From the needless (“beautiful”) Euro-styled cable-stay tower design to the (supposedly) modular fast-track construction techniques … this project was all about making “statements” … rather than making an actual, functional, bridge.
I was fortunate enough to actually take an engineering class from T.Y. Lin … the father of post-tensioned and pre-stressed concrete (he was quite an egomaniac … although probably deservedly so). The precise execution (construction) techniques and materials for post tensioned structures are essential. I expect he would be aghast at this project, and would quickly discover the FAIL point.

Lemon: I feel sorry for your significant other, you are one mean spirited, evil, soul-less individual.

this whole bridge design and construction sequencing seems convoluted and risky … why?
People are focusing on the SJW narrative, but I’m willing to bet a beer that the ultimate reason will be “we didn’t want to shut down the major highway while we were deploying the bridge”.

Not a very good explanation, and what is the purpose of all the fowl language? What everyone seems to be missing is that this is a cable-stayed bridge design. Like any suspension bridge, the bridge deck is not designed, or expected to, support its own weight. That is the job of the cable stays. Not the puny tension rods inside the concrete, but the large cables extending from the (not yet constructed) tower to the bridge deck. That deck weighed 5 tons per linear foot, and spanned about 170 feet. And that puny hydraulic jack pulling on a single cable was going to hold it up? No way, because it was never designed to to that. It is absolutely insane that they built this bridge backwards from all suspension bridges, and I think that people cannot accept that they were that stupid, and as a result are searching for answers in all the wrong places. Look at any suspension or cable salted bridge under construction, and you will see that the towers are always built first. And look again at the Miami bridge. You will see that the columns between the deck and roof are angled at the exact angle the cables from the tower would be pulling on them. They were never designed to support the loss themselves. If for no other reason, the angles are completely working for a truss style bridge.

12 Replies to “The FIU Bridge Collapse”

Navigation