Miami Pedestrian Bridge, Part VI 31

[The Mad Spaniard]

Greetings to all

Our fellow members JAE SFChralie and Retiredat46 (and may be others) have commented in something that could be relevant to all.

IF , and lets say for now without any proof at all in this case and in a general hypotetic case, that an engineer has signed and sealed a set of plans that causes a collapse with deaths of an structure based on a mistake in the calculations/plans, or anything to do with design, what are the cconsequences:

Loss of license forever after being found guilty by the Board after the Board gets a complain by a member of the public (annonimous or not)????
Jail, if a criminal case is brought???
Civil penalties, if a case is brought by the families of those that were affected?

These are probably easy to be determined based on previous cases (do you guys can present any similar cases in the state of Floridaor elsewhere?)

But, what about the P.E's that designed the critical members or oversaw or checked the project without signing and sealing? Can a case be brough against them similar to that against the EOR? What happens to the "peons" that do not get the "big bucks" given to the Project Managers?

The interesting thing is that in the case of an owner/s without a P.E. they may only loose the company (or maybe not) or just some money...

These are scary thoughts for all that have a P.E.

Food for thought..

 

[JAE]

Well, there is the Hyatt Regency walkway collapse in Kansas City in 1981.

Here's a link to an Engineering.com article on it.

https://www.engineering.com/Library...cleID/175/Hyatt-Regency-Walkway-Collapse.aspx

A relevant quote:
[blue]Due to evidence supplied at the Hearings, a number of principals involved lost their engineering licenses, a number of firms went bankrupt, and many expensive legal suits were settled out of court. The case serves as an excellent example of the importance of meeting professional responsibilities, and what the consequences are for professionals who fail to."[/blue]



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[hpaircraft]

Well, if the DESIGN was flawed then yes. But after over 1000 posts on this set of threads there is still a lot unknowns and the investigation could possibly result in a sequence, stressing, construction, contractor error vs. an engineer error. We'll see I guess...

It might be within the realm of possibility that a construction fault caused the collapse. However, for a construction fault to cause the bridge to so completely underperform its specification (and I'm pretty sure they specified "doesn't fall down under its own weight"), it would have to be simultaneously very serious so as to use up all available factor of safety, but also very subtle so as to escape notice in all of the various layers of inspection. And construction codes and inspection regimes are specifically designed to catch or at least mitigate such errors. Note for example the emails observing that the lateral PT members were not exactly located per plan. I think that the far more likely scenario is the failure of imagination that we've pretty exhaustively illuminated in Parts I through V on this topic: the failure to anticipate the need for a robust shear connection between the 11/12 junction and the deck.

--Bob K.

 

[JAE]

Bob
In other words... if the structure strength/stability is that sensitive to contractor induced variations then there’s simply an inherent design flaw.

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[dik]

As JAE notes, there are several issues the NTSB has to examine; they include:
Construction Contract,
Construction Documents including Drawings and Specification,
Change Orders and other changes to the Contract,
Any drawings or sketches prepared for clarification or intent,
Any Field Orders,
Minutes of all meetings between the Engineer and the Contractor,
Any unrecorded changes to the Work,
Any QA/QC undertaken by the Contractor and the Engineer,
Any shop drawings submitted, and any shop drawings reviewed by the Contractor,
Any shop drawings submitted, and any shop drawings reviewed by the Engineer,
Any eMails and correspondence between the Owner, Contractor, and Engineer,
Any Field Notes made by the Contractor or the Engineer or Other parties,
A mandated peer review,
Any Site Construction Reports prepared by the Contractor and Engineer or Other parties, and
All visits by the FDOT guys (a government agency may play down the role of these guys).

I've probably missed a few... but, it's a good start.

 

[dik]

I suspect strongly that there was a serious design flaw at one or more of the 'nodes', but, I don't have enough information to go beyond 'suspect strongly'. There has not been enough information, of the right kind, to go beyond. There could be a couple of other plausible reasons for the collapse.

I'm glad that Tesla released their information to the public; I'm not thrilled that the government is controlling all information released. Anyone reporting to the NTSA should do so under the condition that any information provided to them may be released to the public (off my apple box).

Dik

 

[dik]

Loss of license forever after being found guilty by the Board after the Board gets a complain by a member of the public (annonimous or not)????
Jail, if a criminal case is brought???
Civil penalties, if a case is brought by the families of those that were affected?

I think 'Mad' is being redundant... We'll have to wait and see what charges can/will be filed. If the engineer that made the site visit and viewed the crack and followed it up with a statement that it was nothing to be concerned about is incorrect. If the crack was a serious precursor to the failure, he could be in serious trouble. We'll have to wait, and, hopefully the Statutes of Limitations doesn't pass before the NTSB releases its report.

Dik

 

[dik]

These are scary thoughts for all that have a P.E.

Not scary, but, sobering... after a while you get used to it, and, it just becomes a part of a way of life. I often see structural issues without consciously looking for them... as, I assume most structural guys do.

Dik

 

[hokie66]

dik,
Your list should include the mandated design peer review.

 

[Retiredat46]

Do we know for sure that there are pictures of the cracks that were the subject of Denney Pate's voice mail on March 13? Of course, we don't know exactly where (other than "the north end of the span") or how serious the cracks were, either. It seems like any pictures would have been released by now if they exist.

 

[SFCharlie]

Retiredat46 (Aeronautics)
NTSB has embargoed release of anything since Feb 2018.

 

[Retiredat46]

The very end of video 00560MTS from those posted by jrs87 (Mechanical)30 Apr 18 13:12 briefly shows the bottom of the 11/12 area before the move. Is that worth zooming in on for a closer look?

 

[LittleInch]

Looks like a fight between Florida and Federal laws on release of documents is under way.

http://www.miamiherald.com/news/local/community/miami-dade/article210298454.html

Given that we seem mainly to be looking at the member 11/12 connection to the deck issue I still wonder how much design went into the short term single span design compared to what the bridge would look like and act when both spans were present and apparently locked together to give support and resistance to movement / stress.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[jrs87]

"failure of imagination"

I would add it seems likely something never encountered before arose regarding shear between 11 and deck. I don't know if member 12 really had any structural significance except for canopy end support. Hinges were placed on member 1 to allow for different thermal expansion of deck and canopy, so member 1 was not structurally significant.

I, like a couple of other posters, would like to know more about the shims on north landing. There were 4, and spaced such that the diaphragm area under 12 was floating. What if (big if) the shims were wrong and two inner shims did not fully make contact? The span did seem to rock a little hard when lowered.

If it turns out design anticipated other section of bridge was required to fully stabilize 11 and they just said to themselves "don't allow live load until entire structure is complete", I will be horrified.

If this bridge was innovative and first-of-its-kind, it would have been prudent to make test models in the lab first. Is it industry practice to make the bridge itself the prototype? Did they have plans for this concept to be implemented all over the world? I don't think so.

I don't think we have to wait for NTSB report to conclude the allure of public funding lead to untested decisions and design constraints. Add to that a little social engineering.... If FIU/Sweetwater was using their own money, this overpass would have been completely different.

"zoom in"

The additional application of a white finish to members would probably obscure cracks except at close focus.

 

[dik]

Your list should include the mandated design peer review.

I've added it, but, I'm not sure I agree with this requirement. Two eyes are always better, but, my experience with peer reviews is not great.

Dik

 

[dik]

Do we know for sure that there are pictures of the cracks that were the subject of Denney Pate's voice mail on March 13? Of course, we don't know exactly where (other than "the north end of the span") or how serious the cracks were, either.

We don't, just my speculation... I know if I were on site and saw them, first thing out of my pocket would be my camera. It's possible, but, I cannot imagine an engineer seeing cracks that were worthy of mention (if only to say they were of no consequence) not taking photos. Photos may not have been taken, but if they were consequential, the Engineer may be in for a pile of heartburn.

Dik

 

[JAE]

At least in our region, state DOT's typically require a complete, independent, second design check on all calculations and drawings for bridges.

In addition, the state DOT would also have their own engineers review.

In this case, with the primary client being a university, I'm not sure how intensely involved was the Florida DOT.

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[dik]

Looks like a fight between Florida and Federal laws on release of documents is under way.

I hope they are successful... we seem to have lost sight of what 'public servant' means.

Dik

 

[dik]

The additional application of a white finish to members would probably obscure cracks except at close focus.

My experience is that adding a coating (and, not a heavy high build), makes cracks more visible.

Dik

 

[dik]

I'm not sure how intensely involved was the Florida DOT.

This will be an interesting facet of this collapse. For their sake, I hope they were not involved, but, you know how governments work.

Dik