Miami Pedestrian Bridge, Part VIII 80

[JAE]

A continuation of our discussion of this failure. Best to read the other threads first to avoid rehashing things already discussed.

Part I
thread815-436595

Part II
thread815-436699

Part III
thread815-436802

Part IV
thread815-436924

Part V
thread815-437029

Part VI
thread815-438451

Part VII
thread815-438966



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[hpaircraft]

The report was exactly what NTSB can release at this point in their investigation, and it is exactly what they are supposed to release. It sets forth the facts that are knowable by inspection (what happened, when, and where, etc) and lays the groundwork for the ensuing investigation. It does not speculate.

 

[dik]

hpaircraft... it was pretty light for that even. It did not provide any factual information they had. The information has been specifically held back, so, characters like those on this forum could not come up with 'real' information. To reiterate, the report was useless, and, a waste of paper and manhours.

Dik

 

[SFCharlie]

The reason that the NTSB is so backlogged is due to budget cuts. They have only just gotten around to holding the hearings on the train crash outside of Tacoma. They will hold hearings on the FIU bridge and they will leave no stone unturned. Everyone will take their turn being grilled. Be patient.

SF Charlie
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[Rigobertito]

Please

According to the plans that are available, is this all the steel that crosses the joint?

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1531928546/tips/BridgeII11_ifk6xc.bmp[/url]

 

[The Mad Spaniard]

Greetings toall:

Regarding the calcs, you can do what I did: contact FIU . It will cost you only 47 bucks to get them. See Below their response to my e-mail request.


Good afternoon,

We estimate one hour’s worth of personnel time to prepare and provide the structural calculations documents for production, which would be a charge of $47.00 for these documents and a link to download the documents will be provided. Upon receipt of payment for this charge, we will proceed to prepare these documents for production. Please provide the payment in the form of a check made payable to "Florida International University" and remit the check to our office so that we can proceed with providing you with responsive records. Further, please be advised that we will not be gathering any documents until we receive payment. Lastly, you should be aware that if a requesting party fails to respond to inquiries for clarification, cost estimates, or any other communication from the University for 30 days, the request will be closed.

Thank you and have a nice day.
Lizvette Torres, Paralegal
Office of the General Counsel
Florida International University
Modesto A. Maidique Campus
11200 Southwest 8th Street, PC 511
Miami, FL 33199
Direct: 305.348.0382 | Main: 305.348.2103 | Fax: 305.348.3272

https://generalcounsel.fiu.edu/

Florida International University (FIU) is subject to the State of Florida’s public records law under Chapter 119, F.S., which provides that any records made or received by any public agency in the course of its official business are available for inspection, unless specifically exempted by the Florida Statutes and/or other applicable federal laws.



From: Me
Sent: Monday, April 30, 2018 12:40 PM
To: Lizvette Torres <lizvtorr@fiu.edu>
Subject: RE: FIU Pedestrian Bridge Collapse

Greetings from here:

Thanks for your prompt response,

For the purpose of transparency, may FIU post these calcs the same way that the Contract Plans have been posted and now are available to the public:

https://cdn2.fdot.gov/fiu/13-Denney-Pate-signed-and-sealed-FIU-bridge-construction-plans.pdf

Again, just a PDF will do for most of the engineering public because it is critical to us to know if there is something in our standard calculation procedures that we may not be aware and needs to be addressed in the AASHTO and FDOT Codes and Specifications.

Best regards

Me




From: Lizvette Torres [mailto:lizvtorr@fiu.edu]
Sent: Monday, April 30, 2018 9:36 AM
To: You
Cc: Lizvette Torres <lizvtorr@fiu.edu>
Subject: FW: FIU Pedestrian Bridge Collapse

Good morning,

Our office is in receipt of your request dated April 27, 2018, for Public Records. The Office of the General Counsel will be overseeing the University’s response to your request. If a cost is associated with gathering these documents, you will be provided with a good faith estimate of the costs as quickly as possible. If no estimate is necessary, responsive documents will be provided to you within a reasonable period of time.

Thank you and have a nice day.
Lizvette Torres, Paralegal
Office of the General Counsel
Florida International University
Modesto A. Maidique Campus
11200 Southwest 8th Street, PC 511
Miami, FL 33199
Direct: 305.348.0382 | Main: 305.348.2103 | Fax: 305.348.3272

https://generalcounsel.fiu.edu/

Florida International University (FIU) is subject to the State of Florida’s public records law under Chapter 119, F.S., which provides that any records made or received by any public agency in the course of its official business are available for inspection, unless specifically exempted by the Florida Statutes and/or other applicable federal laws.



From: Me
Sent: Friday, April 27, 2018 4:16 PM
To: Office of the General Counsel <generalc@fiu.edu>
Subject: FIU Pedestrian Bridge Collapse

To whom it may concern:

Please provide public access to the signed and sealed structural calculations for the FUI Pedestrian Bridge that recently collapsed. How can a member of the public get that information?

Best regards

 

[chris snyder]

Good job - I wouldn't even know who to contact.
This answers a question I had from the long, detailed article. The docs the engineers looked at are still available to the public.. when article said ~"docs not available except to those close to the investigation" it meant those that Miami Herald is suing for (docs between Feb 19 and Mar 15). We were fortunate those photos/memo dated 2/28/18 were "leaked".

Is this the 2000 pages the four engineers in article went through? in what kind of format? (I assume not printed) $47 is cheap...
I'm most curious if there are any calculations for connections. All are about the same.

 

[The Mad Spaniard]

Trust me, it is worthy to get the cals. They are in PDF and about 2000 pages. As they are the calcs for the signed and sealed drawings, they contain calcs about the connections.

The 47 bucks are a very small price for some answers to many questions. But again, we do not have the info regarding what else it was done to propose to stress those bars the day of the failure.

 

[TheGreenLama]

Trust me, it is worthy to get the cals.

Pay To Play. I think I'll take a pass.

 

[The Mad Spaniard]

Another preliminary report from NTSB is out. It shows the pics of the cracks after trhe bridge had been moved (and , I guess, the ones tha Pate said to Tom Andres that were nothing to worry about.)


THE CRACKS ARE HUGE!!!!! THIS IS CRAZY!!!! THE BRIDGE IS TELLING THAT IT IS IN TROUBLE!!!!!

HOW ANYBODY CAN FIX THAT OVER TRAFFIC!!!!!!

 

[The Mad Spaniard]

Here it is for all to see

https://www.ntsb.gov/investigations/AccidentReports/Reports/HWY18MH009-investigative-update.pdf

 

[BridgeSmith]

OMG! With cracks like that in and around a critical member, they didn't shut down traffic while they worked on it? That's beyond unbelievable, it's irresponsible. It may be found to be criminal, but we'll see.

 

[bimr]

Here is that message so you don't have to look for it:

“Hey Tom, this is Denney Pate with FIGG bridge engineers. Calling to, uh, share with you some information about the FIU pedestrian bridge and some cracking that’s been observed on the north end of the span, the pylon end of that span we moved this weekend,” Pate said."

“Um, so, uh, we’ve taken a look at it and, uh, obviously some repairs or whatever will have to be done but from a safety perspective we don’t see that there’s any issue there so we’re not concerned about it from that perspective although obviously the cracking is not good and something’s going to have to be, ya know, done to repair that. At any rate, I wanted to chat with you about that because I suspect at some point that’s gonna get to your desk. So, uh, at any rate, call me back when you can. Thank you. Bye.”

Agree that it is crazy.

Did Denny Pate actually inspect the bridge himself or did he send a Newbie to look at it.

 

[chris snyder]

Unreal. A clear indication to do some serious analysis of the forces at that connection.
I wonder if #1-2 cracked at all.. they'd already tightened those rods and it held.
Won't do it now, but will go back and see how this fits with GreenLama's theory - these cracks show initial step of failure.

https://www.eng-tips.com/viewthread.cfm?qid=438966

6 Jun 18 21:21

I sense the trigger was described by Gwideman way back... tightening the rods pulled #11/12 toward the edge of the deck.

https://www.eng-tips.com/viewthread.cfm?qid=436924

23 Mar 18 17:09
Same theory in "Polish guy's" video

https://www.youtube.com/watch?v=znzCubAWIeo&feature=youtu.be

Cutterhead had calculated #11/12 would only have to move about 0.024" to weaken the structure to a point of failure - that showed on first crack photos before it was moved.

https://www.eng-tips.com/viewthread.cfm?qid=437029

29 Apr 18 02:27

It's amazing (and bad) that the span didn't collapse when they moved it.

Tony Pipitone said it was a matter of pride for FIU and FIGG that ABC only required traffic to be stopped when the span was moved into place. I can see them not wanting to say it needed redesign and start over (as one engineer said should have been done), but it's insane that no one said traffic should be stopped.
The workers on the canopy would have seen this, but didn't have their safety harnesses hitched.. with their experience, I wonder if they'd seen cracks like this before.

 

[RickyTickyTavi]

The cracks appear faulted too. How did they come to the conclusion that everything was okay? Wowsers. This is a lot worse looking. Diagonal 11 appears to have cracks at the top and bottom of the section, 45º, faulted, and quite large.

 

[dik]

Hey, aren't those just shrinkage cracks?... all concrete shrinks, and cracks...

Dik

 

[chris snyder]

to RickyTickyTavi:
First photos (~2/24/18, pre-move, after shoring removed, only supported at ends as in practice) showed a small diagonal crack on east side of #11 that continued north along the deck. In these photos, that crack expanded and #11 appears to have moved north about 1/2" - #12 was breaking loose from the deck. The rebar was still holding (not sheared yet?), but the concrete must have been tearing up inside the members... it looks like #11's upper PT rod had broken loose. Wonder if they could have xrayed this. Unbelievable they didn't stop traffic.

Everyone is silent because they were told to be, but it's hard to imagine someone (intermediate engineer type) wasn't screaming about this.

 

[BridgeSmith]

"It's amazing (and bad) that the span didn't collapse when they moved it."

The stresses at that connection were opposite while it was being moved, and much smaller. Member #11 was in tension holding up the cantilevered end during transport. In place it was in compression, supporting over half the weight of the bridge.

 

[Sym P. le]

Those images are disturbing! To make matters worse, #11 was covered with a banner while the structure sat in this distressed state and was being worked on.

In summary, #11 was no longer functional (as a result of its triple role of compression/tension/(move)/compression) save for the fact that the structure had not already collapsed. Jacking the PT rods just finished blowing the structure apart.

This is beyond stupid!

That may be harsh with the advantage of hind sight, but knowledgeable and competent engineers have the advantage of education, experience and peer scrutiny. Even my trade workers would not have allowed that I be this stupid.

If I've gone too far with this feel free to delete.

 

[Sym P. le]

Also, if the lower deck has become detached from the #11/#12 joint, the resulting deformation would create a hinge effect on the top deck at the #10/#11 joint. In short, this structure was primed for collapse but we already knew that.

 

[3DDave]

There would also be a hinge at the bottom of #10, but neither hinge mattered because neither was intended to have enough strength to make any useful moment resisting contribution. Losing the ability to push that end of the bridge up due to losing the attachment at the base of #11 is the only condition that matters.

I guess the NTSB is not participating in an effective coverup after all. It is curious they have released this data ahead of a final report.