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Miami bridge collapse

Started by Alps, March 15, 2018, 05:38:23 PM

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Alps

http://www.miamiherald.com/news/local/community/miami-dade/west-miami-dade/article205316174.html


This was supposed to be a two span cable stayed bridge. One span was erected and left in place without cable supports or the second, counterbalancing span. Now it collapsed. I'm no structural engineer, but I'm not surprised that the pier collapsed with loading completely different than it was designed for. Any other thoughts?


Duke87

Reminds me of an oft-repeated line from a crotchety old engineering professor where I went to school who refused to ever give partial credit on any homework or exam questions.

"You build bridge, bridge fall down, no partial credit!"
If you always take the same road, you will never see anything new.

bing101


bing101


DJStephens

Some reports stated a "stress" test was being conducted on the structure when it failed.  Perhaps that was post-tensioning?  One has to wonder the wisdom of conducting such as test on the structure over live traffic.   Did work on a project that involved post-tensioning, but it was a segmental design, with all segments in place between piers.   Likely some BSCE's here can more accurately comment, did take determinate and indeterminate structural design, but did not finish the degree, and found indeterminate to be a bear.   

roadman

"And ninety-five is the route you were on.  It was not the speed limit sign."  - Jim Croce (from Speedball Tucker)

"My life has been a tapestry
Of years of roads and highway signs" (with apologies to Carole King and Tom Rush)

J N Winkler

"All aspects of the collapse remain under investigation":  this sounds to me like green-eyeshade study of the plans and erection procedure has turned up no obvious design errors or a priori reasons to expect the collapse to occur.
"It is necessary to spend a hundred lire now to save a thousand lire later."--Piero Puricelli, explaining the need for a first-class road system to Benito Mussolini

roadman65

Lets hope the same mistake is not made in Orlando.  A pedestrian overpass was just built on US 17 & 92 and SR 50 east of I-4 last weekend.  Its not open yet but motorists on Colonial Drive have to pass beneath it.
Every day is a winding road, you just got to get used to it.

Sheryl Crowe

bing101


sparker

Quote from: bing101 on September 19, 2018, 06:36:43 PM
https://patch.com/florida/palmettobay-cutler/fiu-bridge-collapse-osha-fines-5-companies-safety-violations


Update 5 companies are fined for safety violations that lead to the bridge collapse.

Great!  $17.33K mean fine per company; essentially a slap on the wrist.  What's that, a whopping 3 months' salary for the person who died in the collapse?  Let's just hope the courts see fit to apportion the fine to the degree of culpability for the firms involved.  I predict a considerably larger amount will cross the table once the lawsuits commence.   Of course, these firms will appeal the fine and stall any civil action as long as possible -- citing the appeal process, of course.  Betcha these firms won't part with a penny for 5 years or more! :banghead:

roadman

Bumping this thread because the NTSB has released their findings on the collapse:  https://www.ntsb.gov/news/press-releases/Pages/NR20191022.aspx

Full report should be issued in a month or so.
"And ninety-five is the route you were on.  It was not the speed limit sign."  - Jim Croce (from Speedball Tucker)

"My life has been a tapestry
Of years of roads and highway signs" (with apologies to Carole King and Tom Rush)

Max Rockatansky

Quote from: roadman on October 22, 2019, 03:23:55 PM
Bumping this thread because the NTSB has released their findings on the collapse:  https://www.ntsb.gov/news/press-releases/Pages/NR20191022.aspx

Full report should be issued in a month or so.

It really took a year and a half to conclude what was obvious to most people when it fell?  Seems like FDOT got lazy and had unqualified people assessing these new types of pedestrian overpasses.  The design looks like it was way off of what it needed to be strength wise. 

jeffandnicole

Quote from: Max Rockatansky on October 22, 2019, 03:34:56 PM
Quote from: roadman on October 22, 2019, 03:23:55 PM
Bumping this thread because the NTSB has released their findings on the collapse:  https://www.ntsb.gov/news/press-releases/Pages/NR20191022.aspx

Full report should be issued in a month or so.

It really took a year and a half to conclude what was obvious to most people when it fell?  Seems like FDOT got lazy and had unqualified people assessing these new types of pedestrian overpasses.  The design looks like it was way off of what it needed to be strength wise. 

Real life isn't a 1 hour TV show.  And real life means you find what was done right and wrong.  And real life means you figure out where the fault lies.  And real life means you offer recommendations for improvement to the proper departments.

As far as "the design looks way off", the look of it had nothing to do with the bridge collapse.  How that look was constructed was the issue.

Max Rockatansky

Quote from: jeffandnicole on October 22, 2019, 03:47:16 PM
Quote from: Max Rockatansky on October 22, 2019, 03:34:56 PM
Quote from: roadman on October 22, 2019, 03:23:55 PM
Bumping this thread because the NTSB has released their findings on the collapse:  https://www.ntsb.gov/news/press-releases/Pages/NR20191022.aspx

Full report should be issued in a month or so.

It really took a year and a half to conclude what was obvious to most people when it fell?  Seems like FDOT got lazy and had unqualified people assessing these new types of pedestrian overpasses.  The design looks like it was way off of what it needed to be strength wise. 

Real life isn't a 1 hour TV show.  And real life means you find what was done right and wrong.  And real life means you figure out where the fault lies.  And real life means you offer recommendations for improvement to the proper departments.

As far as "the design looks way off", the look of it had nothing to do with the bridge collapse.  How that look was constructed was the issue.

Either way that's a pretty long time to complete an assessment or investigation into anything you have the evidence on hand for...or that's what it looks like to me.  Having been involved in criminal investigations my life (which I'm aware aren't engineering investigations) 18 months to release a report seems long unless it involved an intentional act or was something like a plane crash.  Does anyone know how the process NTSB investigations are vetted through?  I'd be curious to find out what the actual behind the scenes process actually is for incidents like bridge collapses. 

roadman

Quote from: Max Rockatansky on October 22, 2019, 03:56:00 PM
Quote from: jeffandnicole on October 22, 2019, 03:47:16 PM
Quote from: Max Rockatansky on October 22, 2019, 03:34:56 PM
Quote from: roadman on October 22, 2019, 03:23:55 PM
Bumping this thread because the NTSB has released their findings on the collapse:  https://www.ntsb.gov/news/press-releases/Pages/NR20191022.aspx

Full report should be issued in a month or so.

It really took a year and a half to conclude what was obvious to most people when it fell?  Seems like FDOT got lazy and had unqualified people assessing these new types of pedestrian overpasses.  The design looks like it was way off of what it needed to be strength wise. 

Real life isn't a 1 hour TV show.  And real life means you find what was done right and wrong.  And real life means you figure out where the fault lies.  And real life means you offer recommendations for improvement to the proper departments.

As far as "the design looks way off", the look of it had nothing to do with the bridge collapse.  How that look was constructed was the issue.

Either way that’s a pretty long time to complete an assessment or investigation into anything you have the evidence on hand for...or that’s what it looks like to me.  Having been involved in criminal investigations my life (which I’m aware aren’t engineering investigations) 18 months to release a report seems long unless it involved an intentional act or was something like a plane crash.  Does anyone know how the process NTSB investigations are vetted through?  I’d be curious to find out what the actual behind the scenes process actually is for incidents like bridge collapses. 

One to two years is the common timeframe for the NTSB to complete and issue a report on a major accident.  Sometimes it can take even longer (like with the two 737 crashes that were ultimately attributed to a problem in one of the stabilizer components that seldom occurred in service).  And, with respect, have you ever read an NTSB report concerning a major accident like a bridge collapse or a plane crash?   If not, here's the link:  https://www.ntsb.gov/investigations/AccidentReports/Pages/AccidentReports.aspx    Lots of reading material that may give you some good insight as to how the NTSB conducts their investigations.
"And ninety-five is the route you were on.  It was not the speed limit sign."  - Jim Croce (from Speedball Tucker)

"My life has been a tapestry
Of years of roads and highway signs" (with apologies to Carole King and Tom Rush)

US 89

Quote from: Max Rockatansky on October 22, 2019, 03:34:56 PM
It really took a year and a half to conclude what was obvious to most people when it fell?  Seems like FDOT got lazy and had unqualified people assessing these new types of pedestrian overpasses.  The design looks like it was way off of what it needed to be strength wise.

According to this USA Today article I read today, FDOT didn't have much of a role in this because the construction was primarily overseen by FIU and there was no requirement for an FDOT inspector on site. They recommended giving FDOT more authority over future projects like this one.

roadman

"And ninety-five is the route you were on.  It was not the speed limit sign."  - Jim Croce (from Speedball Tucker)

"My life has been a tapestry
Of years of roads and highway signs" (with apologies to Carole King and Tom Rush)



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