Thursday, March 15, 2018

950 ton, 30' wide, 174' long, bridge built to allow Sweetwater's Florida International University students to cross above a busy street to cross "safely" has collapsed suddenly, proof that it wasn't safe 5 days after being placed, and a year before opening to pedestrians and cyclists.


at least 4 vehicles were flattened. Several people are wounded, several are dead, and it's going to be awhile until the span is lifted and a full press release occurs.

And with two architectural bridge engineering firms partnered to design and build it... this is going to be a long delayed diagnosis as to the cause, and no doubt will go forgotten and unnoticed years from now.

I doubt the bridge was tested once installed, to determine the load bearing ability. I wonder if was even going to be tested?

"The bridge was reportedly put to a "stress adjustment" before it collapsed over traffic before 2 p.m. on Thursday. Two workers were on top when it pancaked on top of vehicles waiting at a stoplight.

Perez and Miami-Dade County deputy mayor Maurice Kemp would not confirm if that test did take place."


"One factor in the tragedy may have been that adjustment that Miami-Dade Mayor Carlos Gimenez said crews were conducting on the span.


U.S. Sen. Marco Rubio tweeted late Thursday that the cables that suspend the bridge had loosened and the engineering firm ordered that they be tightened. "They were being tightened when it collapsed," he said on Twitter. "


U.S. Sen. Marco Rubio, who is an adjunct professor at the school, noted the bridge was intended to be an innovative and "one-of-a-kind engineering design."

Renderings showed a tall, off-center tower with supporting cables attached to the walkway. When the bridge collapsed, the main tower had not yet been installed, and it was unclear what builders were using as temporary supports.

And for all the fancy computer engineering that went into making a 950 ton slab of concrete that needed to be sound and last for decades... I wonder if anyone considered studying the bridges that have been built and lasted for centuries, and made without computers staffed by young engineers and architects? You know, when only the most experienced geniuses could figure out how to get people over an open space without a support structure underneath.

the oldest bridges in use now are 3000-3200 years old. But the ones that actually have a long enough comparable span are 200+ years old

https://www.nbcsandiego.com/news/national-international/Pedestrian-Bridge-Collapses-Crushes-Cars-Nears-FIU-476984933.html
https://www.fhwa.dot.gov/bridge/steel/pubs/if12052/volume05.pdf
https://www.nbcsandiego.com/news/national-international/Recovery-Mission-Begins-Bridge-Collapse-Florida-International-Universitry-477077943.html?_osource=Newltr_Station_Hdlines_KNSD

7 comments:

  1. Remember, that was built by Union Labor.

    ReplyDelete
    Replies
    1. wow, good point. Time to put the unions responsible for this in the limelight

      Delete
  2. Most likely it's either design deficiencies, which will come back on the engineer - or it wasn't built to spec, which will come back on the construction manager. Labor follows the plan interpretation by the construction management team - very unlikely they'll take any blame.

    ReplyDelete
  3. Just looking at it from an engineering point of view it seems to be bottom heavy and the truss system contradicts the regular design of them. The cables would appear to make the situation worse by pulling down on the top section. Five days of rumbling traffic was obviously enough to bring it down. While unions are to blame for everything from global warming to the morons in congress who voted to loosen up the bank regulations that prevent financial disaster I think you are drawing a long bow on them being responsible for this piece of deadly engineering and cost cutting.

    ReplyDelete
    Replies
    1. "While unions are to blame for everything" ... easy Bill. Dial back a tiny bit, and maybe you can discuss this with me calmly.

      I'm no lawyer, I'm just a car guy. I'm not sueing anyone, and no matter who I blame or what I say, the world will move along ignoring my nonsense, I think you can agree.

      Lets start with some simple stuff.
      Bridge was built.
      Who did the labor? Union? Non-union?
      If we could get that fact, we could proceed to the next step

      The people that built it, did they screw up? Or, was it the people that designed and engineered it?

      Well? 1st someone has to man up and state that they were the labor, the design, or the engineers.

      So far we DO have two companies involved.

      Until some news outfit gets on the ball and looks at the permits, and then goes to see who did what, we're just supposing.

      Am I wrong though? Did this get built without a union? 950 tons of concrete, and that wasn't a union job? Seriously?

      Possible, not likely.

      Now, suppose you agree with me that it was union built. Union moved, and union placed.

      Isn't the public ready to have the unions responsible brought to the court of public opinion for discussion of their work? Aren't calamities like this a learning experience where the public gets to see the facts, and judge the matter as negligence? Or, force of nature?

      I'd like to know the facts, because this was put in place over the public road, and people died.

      Am I out of line? Don't you allow me the outrage for the deaths of my countrymen? Innocent ones who were driving along?

      What say you?

      Delete
    2. Just watched this account of why the bridge failed due to incorrect tensioning of trusses. https://youtu.be/KtiTm2dKLgU

      Delete
  4. Makes you realize what an engineering feat the Bailey Bridge of WWII was ...
    see: https://www.youtube.com/watch?v=aFGh97Bg3cc
    and: https://www.youtube.com/watch?v=0eGZGWL3zwA

    ReplyDelete