Miami Pedestrian Bridge, Part XIV 78

[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

Part VIII
thread815-440072

Part IX
thread815-451175

Part X
thread815-454618

Part XI
thread815-454998

Part XII
thread815-455746

Part XIII
thread815-457935

 

[SFCharlie]

I believe M11 was able to actually move toward M10-Canopy. (concrete fails in tension, Rebar Bends? in compression?)

SF Charlie
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[LionelHutz]

The node 10-11 blister was horizontal on top of deck and canopy remnants and appears to be mostly broken free from the rest of what remained. The left over angled canopy piece was broken to the north of the blister so the part of the canopy where member 11 actually connected was either on the ground or crushed. The member 11 to canopy connection was definitely not largely intact after the collapse.

From a post by Ingenuity on 16 Mar 18 07:04 in the first part.

Things are really going in circles....

 

[Vance Wiley]

Is that a PT ROD I see?

Maybe from M11?

 

[Sym P. le]

From M10. The sleeve diameter is 4" as opposed to the smaller 3" sleeve in M11. Also, the M10 PT rods sit either side of the M11 PT rods in the anchorage.

 

[Vance Wiley]

Thank you.

 

[SFCharlie]

Is that a PT ROD I see?

Yes, it is probably the lower PT rod in M11, but it could be the upper...

SF Charlie
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[SFCharlie]

Official: U.S. DOT Proposes 10-Year Bar of Contract Awards to FIGG

SF Charlie
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[saikee119]

Official: U.S. DOT Proposes 10-Year Bar of Contract Awards to FIGG

Justice is done finally to a designer refusing to admit own mistakes even up to now.

I have said earlier that my respect of Figg dropped into the gutter when Figg was claiming the FIU bridge was still safe in the morning on the day when the bridge collapsed in the afternoon. Most qualified bridge engineers and RC designers would have known the bridge has gone just by looking at the photos of the extensive cracks right at the most vital locations.

It is also increasingly clear the re-stressing of the two PT rods on a badly cracked 11/12 node has accelerated the demise of the structure.

 

[RFreund]

Just FYI -
Two firms that were involved in the investigation are giving a short talk at the SEAOI (Illinois SE) bridge symposium:

https://www.pathlms.com/ncsea/courses/20483/webinars/11786

The talks seem pretty short so I doubt they will get into anything we'd really be interested in. But WJE is one of the speakers.

EIT

http://www.HowToEngineer.com

 

[Ingenuity]

The first pair of speakers to the link that RFreund provided - their client was a major insurance carrier - state:

They were tasked with documenting the post-loss condition of the bridge, performing a detailed structural analysis to determine the cause and origin of the collapse, evidence collection, and developing conceptual repair/retrofit design options.

Good luck with developing a conceptual repair/retrofit...did the carrier not see the extent of the collapse before setting the tasks?

 

[FortyYearsExperience]

SF Charlie says:
"I have said earlier that my respect of Figg dropped into the gutter when Figg was claiming the FIU bridge was still safe in the morning on the day when the bridge collapsed in the afternoon.:"

Yes, but it is also clear that FIGG did not have anybody on site to assess the crack. The telephone message by Denny Pate does not state that he had seen the cracks. Then, he had to destroy his telephone in the laundry, because it no doubt showed that he had seen nothing, but gave his assurance that it was all OK.

 

[SFCharlie]

Yes, but it is also clear that FIGG did not have anybody on site to assess the crack

I though we knew that FIGG if not Denny Pate, had someone on the bridge the morning of the collapse taking pictures? I'll check.

SF Charlie
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[RVAmeche]

If I remember Pate's voicemail correctly, it implied he was shown pictures of the cracks, which he claimed were not safety issues.

 

[FortyYearsExperience]

When he says "Um, so, uh, we've taken a look at it," it certainly does not mean "I" have taken a look at it. Someone without qualification reported it. See below. The phone was destroyed for a reason.

"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. 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."

 

[hokie66]

The voicemail was 2 days before the collapse. There was a meeting on site the morning of the collapse. Attendees at that meeting were reported, but I don't remember whether Pate was physically there, but he participated and gave assurances that all was under control.

 

[FortyYearsExperience]

One thing is certain. Everybody who saw the cracks just before failure was not qualified to assess them. Anybody who saw the cracks and who was qualified to assess them would have personally run into the road to stop the traffic passing beneath.

 

[hokie66]

Denney Pate and another FIGG engineer were in the meeting just before the collapse occurred. Another FIGG engineer was on the phone, as indicated by the minutes of the meeting. If they were not qualified to assess the cracks, that is very sad.

https://www.nbcmiami.com/news/local...s-on-morning-of-fiu-bridge-collapse-2/158393/

 

[Ingenuity]

It would be equally very sad if Denney Pate was indeed at the site meeting (on the morning of afternoon collapse, which I believe he was) and did NOT personally visually observe the cracking before attending the meeting.

 

[hokie66]

That report said that two engineers from FIGG, Denney Pate and Eddy Leon, were at the meeting. And at 8 AM, before the meeting, it said that the engineers climbed onto the bridge and saw the cracking.

 

[Ingenuity]

Thanks hokie66 for confirmation.

Very sad that FIGG (EoR with significant past-experience as a senior bridge design engineer) personally witnessed that degree of cracking/distress then attend a meeting stating:

FIGG "assured" those in the meeting "there was no concern with safety of the span suspended over the road," the minutes state.