Engineer reported cracks in bridge before fatal collapse - transportation agency

[rooster59]

Engineer reported cracks in bridge before fatal collapse - transportation agency

By Zachary Fagenson

 

Workers prepare to remove debris from a collapsed pedestrian bridge as a police drone flies past at Florida International University in Miami, Florida, U.S., March 16, 2018. REUTERS/Joe Skipper

 

MIAMI (Reuters) - The engineer overseeing a newly built footbridge that crumbled onto a Miami roadway, killing at least six people, had called the state Transportation Department two days before the collapse to report cracks found in the span, the agency said on Friday.

 

But the engineer's message, including his assertion that the cracking posed no safety issue, was left on the answering machine of a department employee who was away from the office at the time, and it was not retrieved until Friday, a day after the tragedy, according to the agency.

 

The 950-ton, $14.2 million pedestrian bridge, which crossed an eight-lane highway adjacent to Florida International University (FIU) to link the campus with the city of Sweetwater, collapsed on Thursday, crushing vehicles in traffic below.

 

Late on Friday, the Florida Department of Transportation (FDOT) released a transcript of a voice-mail message the agency said was left by Denney Pate, senior vice president and principal bridge engineer for private contractor FIGG.

 

In it, Pate said his team had observed "some cracking" at one end of the bridge and that repairs were warranted, "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."

 

He added: "Obviously the cracking is not good and something's going to have to be, 'ya know, done to repair that."

 

The transportation agency described Pate as "FIGG's lead engineer responsible for the FIU pedestrian bridge project" and part of the walkway's "design build team." He did not immediately respond to email queries from Reuters seeking comment on the matter.

 

The disclosure came hours after U.S. Senator Bill Nelson of Florida demanded documents related to the design, construction, safety and inspection of the fallen bridge while federal and local investigators worked to determine the cause.

 

"If anyone dropped the ball and it contributed to this tragedy, then they should be held accountable," Nelson, the ranking Democratic member of the Senate Committee on Commerce, Science and Transportation, wrote to the FDOT.

 

At least six people were confirmed killed, and police have said more bodies may be recovered from the rubble. The accident occurred just five days after the 174-foot-long (53-meter)bridge, assembled by the side of the highway, was installed during a six-hour operation.

 

"We know that there's people missing, the family members know that there's people missing, and what we can tell them is that we can assume that they're in there," Juan Perez, director of the Miami-Dade Police Department, said at a news conference.

 

The victims have not been publicly identified, but at least one was a female university student, officials said.

 

At least 10 people were taken to hospitals; two remained in critical condition on Friday, officials and local news media reported.

Uncertainty over the stability of remaining sections of the bridge hampered rescue efforts, officials said.

 

Some news media accounts reported that engineers may have been conducting a stress test that might have led to the collapse. But the state Transportation Department said it had no knowledge of any such tests being scheduled since the bridge was installed last Saturday.

 

It was too early to say whether anyone might face criminal charges, Perez said.

 

National Transportation Safety Board officials were on the scene on Friday to investigate.

 

Munilla Construction Management (MCM), which installed the bridge, said it was devastated by what happened, was cooperating with investigators and doing everything it could to help.

 

The Miami-based company, which also has operations in Texas and Panama, employs about 500 people and specializes in civil projects, airports and educational facilities. Since being founded in 1983, it has handled billions of dollars worth of projects in Panama, Florida and the U.S. Southeast.

 

MCM appeared to have the backing of Miami-Dade County to build a planned $800 million bridge between Miami and Miami Beach, even receiving the county's support in a lawsuit seeking to block Florida officials from awarding it to a competitor.

 

According to campaign finance reports, the company and the five brothers who own it give generously to candidates at the local, state and federal level. MCM officials did not respond to requests for further comment on Friday.

 

The Florida Transportation Department said on Friday that one of its consultants on the project attended a meeting with members of the bridge design and construction team shortly before the walkway failed and was "not notified of any life-safety issues."

 

 

-- © Copyright Reuters 2018-03-17

[overherebc]

Dark blue showing deck fitted and support tower and cables not yet in place.

[tigermoth]

3 hours ago, overherebc said:

Dark blue showing deck fitted and support tower and cables not yet in place.

I find the above diagram amazing. You do not design a bridge of this nature unless the unconstructed tower and cables are 100% necessary. How it could possibly be open for use without these components in place is unbelievable. The connection between the construction company and city authorities is highly suspicious and requires a full and independant investigation. Heads will roll over this.

[overherebc]

18 minutes ago, tigermoth said:

I find the above diagram amazing. You do not design a bridge of this nature unless the unconstructed tower and cables are 100% necessary. How it could possibly be open for use without these components in place is unbelievable. The connection between the construction company and city authorities is highly suspicious and requires a full and independant investigation. Heads will roll over this.

It wasn't open for use. That it seems was planned for well in the future. The dark blue section had been put in place only 5 days before. The tests/tensioning were being done on that part when it let go.

I would still love to know when the section was cast, one week, one month whatever before moving it to site, ie was it still a bit green and not fully hardened etc.

[FitnessHealthTravel]

It's scary they're still not getting it right in 2018. RIP to the victims. I'm sure there will be a report on 'where the steel came from' too

[overherebc]

12 minutes ago, FitnessHealthTravel said:

It's scary they're still not getting it right in 2018. RIP to the victims. I'm sure there will be a report on 'where the steel came from' too

I could make a wild but accurate guess on where the steel came from. One of two places.

Used to be part of my job and 99.99% of contracts would state 'No steel to be sourced from xxxxx'  I've seen stainless steel from xxxxx arrive on site with rust starting to appear. It had certification that 'proved' it conformed to spec' but independent lab' tests would prove it wasn't anywhere near what was claimed on the paperwork.

Edited March 18, 2018 by overherebc

[Jonnapat]

No money for repairs, needed to build the Wall.

[overherebc]

1 hour ago, Jonnapat said:

No money for repairs, needed to build the Wall.

Repairs?

[ExpatOilWorker]

5 hours ago, overherebc said:

I could make a wild but accurate guess on where the steel came from. One of two places.

Used to be part of my job and 99.99% of contracts would state 'No steel to be sourced from xxxxx'  I've seen stainless steel from xxxxx arrive on site with rust starting to appear. It had certification that 'proved' it conformed to spec' but independent lab' tests would prove it wasn't anywhere near what was claimed on the paperwork.

Was any of that rusty stainless steel from China?

 

I have seen SS304 from China rust when in contact with sea-water, while Japanese, Italian and American SS generally is of good quality.

[overherebc]

8 minutes ago, ExpatOilWorker said:

Was any of that rusty stainless steel from China?

 

I have seen SS304 from China rust when in contact with sea-water, while Japanese, Italian and American SS generally is of good quality.

Stainless flanges that were rusty when they were unwrapped and yes from where you mentioned.

Japapnese was always looked at as being the best, Italian also good and although never worked with it never heard a bad report about US stainless.

 

[overherebc]

6 hours ago, overherebc said:

It wasn't open for use. That it seems was planned for well in the future. The dark blue section had been put in place only 5 days before. The tests/tensioning were being done on that part when it let go.

I would still love to know when the section was cast, one week, one month whatever before moving it to site, ie was it still a bit green and not fully hardened etc.

I was always under the impression that 28 days was regarded as being the minimum from casting to moving in anyway. Prepared to be corrected.

[Bluespunk]

23 hours ago, rooster59 said:

In it, Pate said his team had observed "some cracking" at one end of the bridge and that repairs were warranted, "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."

Time for a career change.

[Scott]

Off-topic post removed.  

 

[MaxYakov]

22 hours ago, overherebc said:

It wasn't open for use. That it seems was planned for well in the future. The dark blue section had been put in place only 5 days before. The tests/tensioning were being done on that part when it let go.

I would still love to know when the section was cast, one week, one month whatever before moving it to site, ie was it still a bit green and not fully hardened etc.

Additionally, w/r to what could be mistaken for an "over-engineered" design, I saw a model of this bridge and it appeared as though the upper level, the "roof" of the pedestrian walkway. was going to carry vehicular traffic and the required roadway.

Edited March 19, 2018 by MaxYakov

[overherebc]

Google  bridge collapse usa.

Search and there is a very short video of the actual collapse. It 'looks' like a single sudden break through the deck near the bottom of the last angle truss. Only a few seconds clip.

[overherebc]

6 minutes ago, MaxYakov said:

Additionally, w/r what could be mistaken for an "over-engineered" design, I saw a model of this bridge and it appeared as though the upper level, the "roof" of the pedestrian walkway. was going to carry vehicular traffic and the required roadway.

Can't really see that as the stay cables all go through the centre line of the roofing section which doesn't look wide enough. Also no ramps on the finished bridge models.

[MaxYakov]

3 hours ago, overherebc said:

Can't really see that as the stay cables all go through the centre line of the roofing section which doesn't look wide enough. Also no ramps on the finished bridge models.

You are correct. My mistake. I guess I mistook the cable stays on the roof for motor vehicles. And, believe it or not, I watched the complete virtual walking tour video as well. Tsk, Tsk.

 

Now the mystery is how they thought the component that fell would self-support without the pylon and cables. Awaiting the arrival of the NTSB report.

Edited March 19, 2018 by MaxYakov

[overherebc]

28 minutes ago, MaxYakov said:

You are correct. My mistake. I guess I mistook the cable stays on the roof for motor vehicles. And, believe it or not, I watched the complete virtual walking tour video as well. Tsk, Tsk.

 

Now the mystery is how they thought the component that fell would self-support without the pylon and cables. Awaiting the arrival of the NTSB report.

Photo where the cable stays would/should have been attached. If you enlarge it easy to see.

[MaxYakov]

12 minutes ago, overherebc said:

Photo where the cable stays would/should have been attached. If you enlarge it easy to see.

Thanks. Cable stays are not much good without the pylon and the cables, yes? They are additional weight that has to be temporarily supported (or not, depending on whether the structure collapses of its own weight or not  ).

Edited March 19, 2018 by MaxYakov

[overherebc]

20 minutes ago, MaxYakov said:

Thanks. Cable stays are not much good without the pylon and the cables, yes? They are additional weight that has to be temporarily supported (or not, depending on whether the structure collapses of its own weight or not  ).

Cable stay bridges usually start wth the tower then sections of deck are added one at a time growing out on each side of the tower. As each section of deck is added it gets fixed and supported by its own cable.

For me, with this bridge, I would have argued the case for the tower first with cables then deck sections being on temp' supports until cables are attached and tensioned.

Can't see how that would take longer than the method picked here.

[MaxYakov]

13 minutes ago, overherebc said:

Cable stay bridges usually start wth the tower then sections of deck are added one at a time growing out on each side of the tower. As each section of deck is added it gets fixed and supported by its own cable.

For me, with this bridge, I would have argued the case for the tower first with cables then deck sections being on temp' supports until cables are attached and tensioned.

Can't see how that would take longer than the method picked here.

Yep, there appears to be a flaw in this case with the Accelerated Bridge Construction method applied. From a cursory research the seemed very concerned about interrupting traffic flow on the busy road below. The very definitions of irony and back to the drawing board occurred.

 

Of course the computer model of the interim, self-supporting stage said everything was (probably?) going to be A-Ok (heh, heh). Somehow reminds me of the climate computer models. Naaaaah. Forget that I said that.

Edited March 19, 2018 by MaxYakov

[overherebc]

28 minutes ago, MaxYakov said:

Yep, there appears to be a flaw in this case with the Accelerated Bridge Construction method applied. From a cursory research the seemed very concerned about interrupting traffic flow on the busy road below. The very definitions of irony and back to the drawing board occurred.

 

Of course the computer model of the interim, self-supporting stage said everything was (probably?) going to be A-Ok (heh, heh). Somehow reminds me of the climate computer models. Naaaaah. Forget that I said that.

One the statements made very early in the development of compurters ( USA speak )was 'put crap in and a bigger load of crap comes out'

?

Edited March 19, 2018 by overherebc

[Stargeezr]

Well,  I wonder if any lessons were learned from this collapse?

  I sure hope so.

Geezer

[gk10002000]

The published reports indicate workers were tightening the cables at the time.  You don't do any sort of major operation like that with the road open to traffic.  big criminal liability likely here

[nkg]

The bridge was basically a truss, self-supported. The stays were to be pipes to add stiffness and controlling harmonics in high winds. As well as for aesthetics.

[gk10002000]

dash cam video of FL bridge collapes.

 

 

[overherebc]

13 hours ago, gk10002000 said:

dash cam video of FL bridge collapes.

 

 

I just googled for update about 20 minutes ago and watched that.

For me it's so clear the deck just cracked and snapped clean through close to the end.

It will be interesting to find out if that was the area that was reported as having cracks prior to the collapse.

I can't get out of my head the question of how fresh was the concrete. I can't get the accelerated construction expression out of my head either, just seems like 'it is faster so it's cheaper' or bean counters controlling the whole thing.

Edited March 20, 2018 by overherebc

[coulson]

48 minutes ago, overherebc said:

I just googled for update about 20 minutes ago and watched that.

For me it's so clear the deck just cracked and snapped clean through close to the end.

It will be interesting to find out if that was the area that was reported as having cracks prior to the collapse.

I can't get out of my head the question of how fresh was the concrete. I can't get the accelerated construction expression out of my head either, just seems like 'it is faster so it's cheaper' or bean counters controlling the whole thing.

Design and build contract. 

 

Minimum amount of safety required is the maximum allowed.

 

Concrete hadn't cured, rebar looks inadequate. The bridge sheared like it was made of matches.

 

Spanning a live motorway should have involved enormous QAQC and vetting.

 

Design and build, saves money, not lives. 

 

RIP to all the deceased.

[Damrongsak]

1 hour ago, overherebc said:

...I can't get out of my head the question of how fresh was the concrete...

In 1973, a 24 story building under construction in Bailey's Crossroads, VA, USA collapsed because of the premature removal of shoring from beneath newly poured floors. Killed 15 and injured 35.  The building was more or less sliced in half. A few wrists got gently slapped. About 5 years earlier, the same construction company had two floors cave in at an office building due to insufficient wooden shoring, killing three and injuring 29 others.  

 

https://en.wikipedia.org/wiki/Skyline_Towers_collapse

 

[bendejo]

20 hours ago, Stargrazer9889 said:

Well,  I wonder if any lessons were learned from this collapse?

  I sure hope so.

Geezer