6 ms·

What went wrong technically to cause the bridge collapse is only the second half of the story. The first half of the story is that the stakeholders wanted an o

What went wrong technically to cause the bridge collapse is only the second half of the story. The first half of the story is that the stakeholders wanted an over-the-top bridge design, complete with fake cable stays, and out of hubris decided they would use an all-concrete single-truss Accelerated Bridge Construction (ABC) design because all-concrete would look better and the university's (FIU's) engineering department sort of specialized in promoting ABC. What could have been a much cheaper nice looking normally-designed bridge (which would be open today) ballooned (or you could say, was hijacked) into a $10mm+ bridge disaster that would be comedy if people hadn't been hurt and killed. A majority of it was even paid for by federal grants.[1] This is why we can't have nice things. They were so focused on building a nice looking bridge — and meeting deadlines — that they didn't/couldn't allocate sufficient resources to verify the design, verify it was built and moved into place correctly. [1] see page 9 of https://www.transportation.gov/sites/dot.gov/files/docs/briefing-room/306576/amendment-2-ga-tiger-v-fiu.pdf https://www.transportation.gov/sites/dot.gov/files/docs/brie...

dmix 7y ago
> sort of specialized in promoting ABC. Shouldn't they be experts at building them properly then?
- Arnt 7y ago
  Expertise only matters if you're hired, at least hired to review the calculations of the engineers: "the probable cause of the … bridge collapse was … calculation errors made by FIGG Bridge Engineers, Inc." and "Factors in the collapse included … inadequate peer review".
  - myself248 7y ago
    > Expertise only matters if you're hired ... > A bad design with a good presentation is doomed eventually. A good design with a bad presentation is doomed immediately. -- Akin's Laws of Spacecraft Design
juliusmusseau 7y ago
> stakeholders wanted an over-the-top bridge design [...] Nothing wrong with that! > They were so focused on building a nice looking bridge — and meeting deadlines These are also good things. To me sounds like the civil engineers started behaving more like software engineers. The independent peer reviewer they hired was not qualified to do the review. > Louis Berger was not qualified by the Florida Department of Transportation to conduct an independent peer review and failed to perform an adequate review of the FIGG Bridge Engineers design plans and to recognize the significant under-design of the steel reinforcement within the 11/12 node, which was unable to resist the horizontal shear between diagonal 11 and the bridge deck. This whole business of the engineers ignoring the cracks that the contractors kept needing reassurance about is also insane.
- varjag 7y ago
  > To me sounds like the civil engineers started behaving more like software engineers. Things like these were common in construction before software engineering was a thing. It always makes me chuckle when someone defers to "if we built buildings like we build software" trope. We do, and worse. Lots of constructions standing around the world are not up to the codes in zillion different ways. They are still standing because redundant nature of physical construction is more forgiving than execution on a Turing machine.
  - paganel 7y ago
    > Things like these were common in construction before software engineering was a thing I read in an architect's memoirs that when he was a student back in the 1940s whenever his Architecture faculty teacher and his students visited a construction site to maybe change some small details (or at least they were perceived as "small" by said architects) oftentimes they were met with very angry construction site workers who would make the above architects think again about trying to force the implementation of those small changes. A similar story was told to me by my father (also a civil engineer) as happening in the 1980s, though the level of implied violence coming from the construction workers was a little more subdued. Wish that we in the software industry would be like those construction workers from time to time.
masonic 7y ago
"What could have been a much cheaper nice looking normally-designed bridge (which would be open today) ballooned (or you could say, was hijacked) into a $10mm+ bridge disaster..." This exactly parallels the disaster that is the new span of the (SF-Oakland) Bay Bridge. What would have been a $400M fully-functional replacement instead became an $8 billion art piece that is less safe and needs far more maintenance.
justinclift 7y ago
This bridge collapse was featured in an episode of Engineering Catastrophes a few weeks ago. According to the narrator, although FIU has a department for ABC they weren't consulted nor involved with the bridge project (and were not happy about it?). No idea how accurate that statement by the narrator is.
- jimmydddd 7y ago
  I attended a US engineering university that built a new engineerng building with extensive solar panels. The building was fine, in general, but the solar panels never worked as intended. The school's engineering professors always made it a point to emphasize that they were not consulted in the planning of the project. :-)
m0llusk 7y ago
This is similar to the San Francisco Bay Bridge replacement plan. Instead of the basic designs that were floated a radical design was chose for aesthetic reasons and ended up being damaged during the tensioning process. Now an over the top design that cost at least twice what it should have is unlikely to serve its purpose of providing for earthquake safe transportation over the long term. Municipalities really need to carefully consider the balance of aesthetics, costs, and risks.
- privateSFacct 7y ago
  It wasn't just an aesthetics things - it was a crazy never before done design to have an iconic look + + + regulation.
- Gibbon1 7y ago
  One of the problems was the original design Caltrans developed without any input from Oakland and San Fransisco was aesthetically an ugly piece of shit. Unsurprisingly the mayors of SF and Oakland wouldn't sign off on it. Part of the reason for that is Gray Davis wanted the bridge construction to start as soon as possible because he wanted to show the voters he was competent and effective instead of the hapless fool he is.
  - m0llusk 7y ago
    The originally proposed design was very basic but also pragmatic and likely to endure. When that design was rejected teams were assembled to come up with a range of designs and pick one that would be suitable. The group that chose the winning design later claimed that they had no comprehension of the design risks and had only renderings and optimistic initial cost projections to work from. There was a process that involved many people and it failed.
michaelt 7y ago
> The first half of the story is that the stakeholders wanted an over-the-top bridge design, complete with fake cable stays To be fair, you can make that criticism of almost every monument and famous building in the world. If the Sagrada Familia didn't have all those over-the-top arched ceilings and all those do-nothing decorative carvings, it'd have been finished decades ago!
- treypitt 7y ago
  Pretty sure the Sistine Chapel is doing fine
  - Someone 7y ago
    https://en.wikipedia.org/wiki/The_Last_Judgment_(Michelangelo)#Before_starting https://en.wikipedia.org/wiki/The_Last_Judgment_(Michelangel...: "The structure of the chapel, built in a great hurry in the 1470s, had given trouble from the start, with frequent cracks appearing. At Christmas in 1525 a Swiss Guard was killed when entering the chapel with the pope when the stone lintel to the doorway split and fell on him. The site is on sandy soil, draining a large area, and the preceding "Great Chapel" had had similar problems."
dsfyu404ed 7y ago
The reason we can't have nice things is that when idiots come along and take a budget that can cover a boring bridge and boring testing then piss it all away on a fancy bridge nobody needs they don't get punished. If anything they get rewarded. The only reason this got noticed is because people died and bodies create opportunities for all the parties that should have stopped this stuff before it started to score virtue points and look like they're doing something cleaning up the mess. If the (metaphorical or literal) tar and feathers came out every time taxpayer money was spent on a boondoggle like this you wouldn't have nearly as many boondoggles like this.
tropo 7y ago
The cable stays were not fake. The bridge was supposed to self-support without them during assembly, without a hurricane or marching band. This does not mean the cable stays were entirely decorative. They had a structural purpose, primarily to change the resonance frequency to be outside the range of ordinary human motion. They were intended to bear some of the load. To me there were obvious problems, particularly the sharp non-articulated corners in the the concrete at the truss edges (high stress points), but of course my concerns would have been dismissed prior to the collapse. Lots of people, with even minimal understanding of mechanical design, should have been alarmed. Maybe that was the point of the design: make something that looks alarming and thus dramatic.
drcode 7y ago
> They were so focused on building a nice looking bridge The bridge was the most hideously ugly bridge ever, behold: https://www.ntsb.gov/investigations/PublishingImages/HWY18MH009-update-fig1.jpg https://www.ntsb.gov/investigations/PublishingImages/HWY18MH...
rdiddly 7y ago
You could go back even further. A bridge collapse was made possible by the building of a bridge. So you could go back to the moment when the do-nothing alternative (cost: $0) was rejected in favor of building a bridge. Well why was that decision made? Let's keep going back. This is where you start running into certain pachyderms in the room. The problem being solved with a bridge, is the existence of 8th Street, a soul- and flesh-destroying 8-lane traffic monstrosity that apparently is sufficiently inconvenient, intimidating and dangerous for human beings to cross unassisted, that a bridge starts to look like a good idea. Seems like the people who allowed 8th St. to happen deserve some of the blame, namely backward-thinking urban "planners" who think it's still 1950, haven't heard of (lalala I can't hear you) induced demand, peak oil or climate change, and who have collectively been sold a bill of goods, and who don't have the imagination to think up any ways of creating "economic activity" in the town that don't destroy the town. This species unfortunately infests the entire continent and kills 35,000 people a year, so I don't expect them to lose sleep over these 6.

dmix 7y ago

> sort of specialized in promoting ABC. Shouldn't they be experts at building them properly then?

Arnt 7y ago
Expertise only matters if you're hired, at least hired to review the calculations of the engineers: "the probable cause of the … bridge collapse was … calculation errors made by FIGG Bridge Engineers, Inc." and "Factors in the collapse included … inadequate peer review".
- myself248 7y ago
  > Expertise only matters if you're hired ... > A bad design with a good presentation is doomed eventually. A good design with a bad presentation is doomed immediately. -- Akin's Laws of Spacecraft Design

juliusmusseau 7y ago

> stakeholders wanted an over-the-top bridge design [...] Nothing wrong with that! > They were so focused on building a nice looking bridge — and meeting deadlines These are also good things. To me sounds like the civil engineers started behaving more like software engineers. The independent peer reviewer they hired was not qualified to do the review. > Louis Berger was not qualified by the Florida Department of Transportation to conduct an independent peer review and failed to perform an adequate review of the FIGG Bridge Engineers design plans and to recognize the significant under-design of the steel reinforcement within the 11/12 node, which was unable to resist the horizontal shear between diagonal 11 and the bridge deck. This whole business of the engineers ignoring the cracks that the contractors kept needing reassurance about is also insane.

varjag 7y ago
> To me sounds like the civil engineers started behaving more like software engineers. Things like these were common in construction before software engineering was a thing. It always makes me chuckle when someone defers to "if we built buildings like we build software" trope. We do, and worse. Lots of constructions standing around the world are not up to the codes in zillion different ways. They are still standing because redundant nature of physical construction is more forgiving than execution on a Turing machine.
- paganel 7y ago
  > Things like these were common in construction before software engineering was a thing I read in an architect's memoirs that when he was a student back in the 1940s whenever his Architecture faculty teacher and his students visited a construction site to maybe change some small details (or at least they were perceived as "small" by said architects) oftentimes they were met with very angry construction site workers who would make the above architects think again about trying to force the implementation of those small changes. A similar story was told to me by my father (also a civil engineer) as happening in the 1980s, though the level of implied violence coming from the construction workers was a little more subdued. Wish that we in the software industry would be like those construction workers from time to time.

masonic 7y ago

"What could have been a much cheaper nice looking normally-designed bridge (which would be open today) ballooned (or you could say, was hijacked) into a $10mm+ bridge disaster..." This exactly parallels the disaster that is the new span of the (SF-Oakland) Bay Bridge. What would have been a $400M fully-functional replacement instead became an $8 billion art piece that is less safe and needs far more maintenance.

justinclift 7y ago

This bridge collapse was featured in an episode of Engineering Catastrophes a few weeks ago. According to the narrator, although FIU has a department for ABC they weren't consulted nor involved with the bridge project (and were not happy about it?). No idea how accurate that statement by the narrator is.

jimmydddd 7y ago
I attended a US engineering university that built a new engineerng building with extensive solar panels. The building was fine, in general, but the solar panels never worked as intended. The school's engineering professors always made it a point to emphasize that they were not consulted in the planning of the project. :-)

m0llusk 7y ago

This is similar to the San Francisco Bay Bridge replacement plan. Instead of the basic designs that were floated a radical design was chose for aesthetic reasons and ended up being damaged during the tensioning process. Now an over the top design that cost at least twice what it should have is unlikely to serve its purpose of providing for earthquake safe transportation over the long term. Municipalities really need to carefully consider the balance of aesthetics, costs, and risks.

privateSFacct 7y ago
It wasn't just an aesthetics things - it was a crazy never before done design to have an iconic look + + + regulation.
Gibbon1 7y ago
One of the problems was the original design Caltrans developed without any input from Oakland and San Fransisco was aesthetically an ugly piece of shit. Unsurprisingly the mayors of SF and Oakland wouldn't sign off on it. Part of the reason for that is Gray Davis wanted the bridge construction to start as soon as possible because he wanted to show the voters he was competent and effective instead of the hapless fool he is.
- m0llusk 7y ago
  The originally proposed design was very basic but also pragmatic and likely to endure. When that design was rejected teams were assembled to come up with a range of designs and pick one that would be suitable. The group that chose the winning design later claimed that they had no comprehension of the design risks and had only renderings and optimistic initial cost projections to work from. There was a process that involved many people and it failed.

michaelt 7y ago

> The first half of the story is that the stakeholders wanted an over-the-top bridge design, complete with fake cable stays To be fair, you can make that criticism of almost every monument and famous building in the world. If the Sagrada Familia didn't have all those over-the-top arched ceilings and all those do-nothing decorative carvings, it'd have been finished decades ago!

treypitt 7y ago
Pretty sure the Sistine Chapel is doing fine
- Someone 7y ago
  https://en.wikipedia.org/wiki/The_Last_Judgment_(Michelangelo)#Before_starting https://en.wikipedia.org/wiki/The_Last_Judgment_(Michelangel...: "The structure of the chapel, built in a great hurry in the 1470s, had given trouble from the start, with frequent cracks appearing. At Christmas in 1525 a Swiss Guard was killed when entering the chapel with the pope when the stone lintel to the doorway split and fell on him. The site is on sandy soil, draining a large area, and the preceding "Great Chapel" had had similar problems."

dsfyu404ed 7y ago

The reason we can't have nice things is that when idiots come along and take a budget that can cover a boring bridge and boring testing then piss it all away on a fancy bridge nobody needs they don't get punished. If anything they get rewarded. The only reason this got noticed is because people died and bodies create opportunities for all the parties that should have stopped this stuff before it started to score virtue points and look like they're doing something cleaning up the mess. If the (metaphorical or literal) tar and feathers came out every time taxpayer money was spent on a boondoggle like this you wouldn't have nearly as many boondoggles like this.

tropo 7y ago

The cable stays were not fake. The bridge was supposed to self-support without them during assembly, without a hurricane or marching band. This does not mean the cable stays were entirely decorative. They had a structural purpose, primarily to change the resonance frequency to be outside the range of ordinary human motion. They were intended to bear some of the load. To me there were obvious problems, particularly the sharp non-articulated corners in the the concrete at the truss edges (high stress points), but of course my concerns would have been dismissed prior to the collapse. Lots of people, with even minimal understanding of mechanical design, should have been alarmed. Maybe that was the point of the design: make something that looks alarming and thus dramatic.

drcode 7y ago

> They were so focused on building a nice looking bridge The bridge was the most hideously ugly bridge ever, behold: https://www.ntsb.gov/investigations/PublishingImages/HWY18MH009-update-fig1.jpg https://www.ntsb.gov/investigations/PublishingImages/HWY18MH...

rdiddly 7y ago

You could go back even further. A bridge collapse was made possible by the building of a bridge. So you could go back to the moment when the do-nothing alternative (cost: $0) was rejected in favor of building a bridge. Well why was that decision made? Let's keep going back. This is where you start running into certain pachyderms in the room. The problem being solved with a bridge, is the existence of 8th Street, a soul- and flesh-destroying 8-lane traffic monstrosity that apparently is sufficiently inconvenient, intimidating and dangerous for human beings to cross unassisted, that a bridge starts to look like a good idea. Seems like the people who allowed 8th St. to happen deserve some of the blame, namely backward-thinking urban "planners" who think it's still 1950, haven't heard of (lalala I can't hear you) induced demand, peak oil or climate change, and who have collectively been sold a bill of goods, and who don't have the imagination to think up any ways of creating "economic activity" in the town that don't destroy the town. This species unfortunately infests the entire continent and kills 35,000 people a year, so I don't expect them to lose sleep over these 6.