Posted on 05/25/2018 3:05:49 PM PDT by PapaBear3625
The National Transportation Safety Board’s preliminary report on the fatal collapse in March of a pedestrian bridge at Florida International University in Sweetwater focuses attention on the widely discussed pre-collapse cracking in the main span. The report also confirms accounts about what the construction crew working on the bridge was doing before the structure fell.
But the report contains no definitive explanation of what occurred and months and possibly years more will be needed to determine the probable cause of the failure, which killed five motorists and one project worker.
(Excerpt) Read more at enr.com ...
I know the root cause of the failure:
Affirmative action engineering.
Contributory factor:
Minority contractors.
Ditto! because of the pc agenda we are all put in danger, minority contractors with no supervision
Interesting. What are the sources of that info?
The answer is already known. The bridge cracked, they detensioned cables to relieve stress and then were re-tensioning it when the bridge faild. They have voicemail from the lead engineer saying it wasn’t a big deal and they allowed the bridge to stay open and killed those people. They also deployed the bridge without the central pylon, which technically might not have been essential but would have prevented the collapse.
It would also have been a nice gesture to close the road while they were dropping it in place....
They performed a stress test while leaving the bridge and street open. HUGE mistake.
And what about the crane operator who closed up shop immediately after the failure and DROVE AWAY? It's been suspected this guy was an ILLEGAL.
Actually I hate to think about bridge beams while
driving. A place I used to work bid and got a contract
to supply formed rebar for them. The contract would not
let us hot form them so they were done cold, this caused
work hardening and often they would break in the middle of
the bend process. We informed them of this but they didn’t
seem to think it worth bothering about.
“We’ve allowed for that etc.”
Bingo; totally agree. Also can lay this at the feet of a politically correct university administration that pressures their contracting shops to hire unqualified entities. If that weren’t enough, the designers had a history of bridge failure and they still got hired!!!
From what I've read, the clearances were such that the placement of the moving vehicles under the bridge had to be changed to accommodate obstructions, thereby altering the stresses on the bridge, leading to the cracking of the concrete, and the "warping" of the internal pipe compression mechanism to the point of uselessness, which meant "FAILURE".
A freeper, perhaps you, posted photos of that. The side that held up had a vehicle support say 15’ from the cantelevered end overhang. The failed side it was say 25’ from the end - and as you say - to avoid the extra shoring, etc. That seems like a good place to start.
Also - seeing as it was a cable bridge, but no cables in place yet - would seem another likely critical factor.
Years?
Sounds like a typical FIB Investigation.
Could you let us know where those bridges are?
Those are places I’d like to avoid.
the Challenger explosion?...
Hyatt Regency?....
So it will take years to allocate responsibility and thus allow the guilty to continue working on other projects. How safe does that make the public feel? There is, somewhere, a ‘PE’ stamp (Professional Engineer) of approval on the plans.
There is a binary decision tree here, did the constructors build to plan or did they make changes without the PE approval? If the former, then the PE is a former PE and responsible! If the latter, then the constructors are liable.
Nonetheless, the decisions to leave the street open to traffic is an obvious 20/20 hindsight major error. This is not the PE making that decision, it is the on-site management and the project owner (FIU). If Political Correctness was a factor here, then that should be brought forward as a causative factor for the fatalities. Risk versus rewards is meaningless when the society hides the responsible parties for reasons other than justice!
It’s politics overriding competence.
An early example was HMS Captain(1870), but back then they called it a ‘vocal but ignorant clamor’
Unfortunately, I don’t know which bridges they
went into. These were 3/4s and 1” + bent into
a 4” radius cold. Sometimes it would fall on a
hard spot in the bar, a place that chilled a little
fast in the rolling process and pow it would snap.
Since we were bending them cold by hand, it took
two men and a 10’ lever, and sometimes we would
take a spill.
Of course now one never knows where steel comes from,
China, Pakistan, India. We used to gripe about Bookuk
steel from South Korea, but now it is probably better
than some.
Not in the business now, retired so not sure.
Enviromental regs throttled the steel industry
so now we have these fine imports.
Challenger - the white male engineers warned them not to launch. It was the hacks at NASA that caused that one. (Or, if you want to trace it back, it was the persecution of the Nazis that built NASA that ultimately led to the disaster.)
The Minnesota bridge wasn’t an engineering failure, it was a combination of anti- icing solution over a period of time, poor maintenance, and parking over a half million tons of equipment on the bridge in addition to the normal traffic weight.
You’ll need to identify which Washington bridge collapse you are discussing (Tacoma Narrows, or Lake Washington, or something else), and identify the engineers on the Hyatt collapse by name so they can be researched.
The bridge was never opened.
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