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Pedestrian Bridge Collapse over SW 8th Street in Miami [pdf]
- eesmith 7y ago"This is a synopsis from the NTSB’s report" about the FIU collapse from March 15, 2018, and not a new collapse, which is what I feared.
- deleted 7y ago[deleted]
- bewaretheirs 7y agoBased on file type alone I assumed it was some sort of formal report rather than a press release and therefore not breaking news.
- js2 7y agoNYT coverage: https://www.nytimes.com/2019/10/22/us/bridge-collapse-florida-international-university-NTSB.html https://www.nytimes.com/2019/10/22/us/bridge-collapse-florid...
- imglorp 7y agoThird party analysis from AvE last year. Usually NSFW language. https://www.youtube.com/watch?v=KtiTm2dKLgU&app=desktop https://www.youtube.com/watch?v=KtiTm2dKLgU&app=desktop
- exabrial 7y agoUsually? ::slaps kneee:: this our beloved redneck from canuckistan. :) Demonetized seems to be the norm
- linsomniac 7y agoTop comment on the linked video: Although the content is very interesting i'm actually here for the foul language.
- exabrial 7y agoIn all seriousness though, I remember watching that video soon after the event. I have to give him credit, he came pretty close to the right conclusions just from a few photographs
- fernly 7y ago> The construction and inspection firms working on the bridge were aware of the cracks and reported the cracks to the design firm, asking for guidance. The engineer of record at the design firm repeatedly indicated that the cracks were of no safety concern. Welp, that's a lawsuit laid out cold right there, setting aside even the fact that > the probable cause of the ... bridge collapse was the load and capacity calculation errors made by FIGG Bridge Engineers, Inc.
- bcaa7f3a8bbc 7y agoAlso, > Errors in design may occur, but systems should be in place to catch those errors when they do occur. In this case, a firm was hired to independently review the bridge design for errors. However, [...] Although the design reviewer recognized that he should have examined the nodes and stages, he indicated that there was not enough budget or time to evaluate those factors. Contributing to this review failure was the reviewing firm’s lack of qualification to do this work.
- duxup 7y agoSo strange. Like even with software there's a point where I tell folks "Look if we're not going to do this X far, it's not of any value to do it half way and claim we did anything here." You'd think there would be some engineering standard where "No this isn't a legitimate review because we didn't do enough." and that might set off some alarms...
- SAI_Peregrinus 7y agoThere is. After the NTSB final report comes out next month I expect both investigations for taking away PE licenses and probably also criminal charges for gross negligence.
- varjag 7y agoThey would raise alarms if it was an unusual exception and not the norm in the industry.
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- baggy_trough 7y agoTo FIGG Bridge Engineers, Inc.: 10. Train your staff on the proper use of Pc (the permanent net compressive force normal to the shear plane) when calculating nominal interface shear resistance. Pretty humiliating. I wonder how bad the damage is to FIGG.
- slenk 7y agoI bet they change their name after the story, like the new Magnum did (from NYT article)
- pnako 7y agoThey can always rebrand as FIGG Demolition. I get that mistakes do happen but this was a bloody footbridge...
- paranoidrobot 7y agoI know this is a joke, but Engineering skill is just as important in safely deconstructing something, as it is in constructing it.
- Gibbon1 7y agoThat's about the most viciously brutal thing I've real all year.
- rwmurrayVT 7y agoI can't imagine they'd survive the massive increase in insurance costs. I also can't imagine any one with a PE would put it at risk by working there.
- waterpond95 7y agoI'm puzzled that they are not pressing charges against FIGG or specific members of staff. Are they not liable for criminal negligence?
- deleted 7y ago[deleted]
- dba7dba 7y agoAnd then there's this accidental destruction of the phone of the engineer who stamped the plans for the bridge. "Denney Pate, who stamped the plans for the bridge, told a judge June 12 that his wife accidentally put his pants with the phone in the pocket into a washing machine, inflicting damage that destroyed any call records or images." https://www.enr.com/articles/47108-bridge-designer-testifies-on-evidence-one-day-after-osha-slams-figg https://www.enr.com/articles/47108-bridge-designer-testifies...
- solotronics 7y agoI am surprised they can't subpeona the phone company for these records.
- cdibona 7y agoNTSB Youtube report: https://www.youtube.com/watch?v=hBjntrebxj8 https://www.youtube.com/watch?v=hBjntrebxj8 The ntsb and us chemical safety board channels are amazing. https://www.youtube.com/user/USCSB https://www.youtube.com/user/USCSB
- bcaa7f3a8bbc 7y agoAfter watching Seconds from Disaster and Air Crash Investigation for many years, USCSB videos are now my favorite accident investigation documentaries.
- lqet 7y agoI don't get this. There were large, steadily growing cracks in supporting elements, observed and documented over multiple days. Why on earth wasn't the street closed down? The bridge slowly and visibly announced its impending collapse, which - as I understand it - is exactly what engineers want. The thing nobody wants is a bridge like the Morandi bridge in Genua, where the signs of impending collapse were hidden under thick layers of concrete, until the structure suddenly and unexpectedly gave way.
- jaclaz 7y ago> ... hidden under thick layers of concrete ... ... and (only for the record) behind false or falsified inspection reports. https://www.corriere.it/english/19_gennaio_31/reports-on-motorway-bridges-at-risk-suspected-of-being-toned-down-c35d1c84-2574-11e9-9fef-1e7c69c121a7.shtml https://www.corriere.it/english/19_gennaio_31/reports-on-mot...
- tropo 7y agoSomething should have been done about the street, but I sure wish it could have been a sign such as: "WARNING Cracking bridge, proceed at own risk, age 18+ only, do not stop near the bridge." We need a way to have something like that be viable from a legal perspective.
- Faark 7y agoBeen following the CSB channel for a while, but thanks for show the NTSB one.
- AmpsterMan 7y agoI lived on the corner of 7th Terrace and 109th AVE during my senior year. I could see the bridge being built from my bedroom window; I would cross 8th Street to go to school everyday. The bridge collapsing was one of the most surreal experiences of my life.
- yay_cloud2 7y agoIt sometimes fascinates me (and scares the shit out of me) to wonder at all of the little errors/assumptions like this that are baked into the millions of spreadsheets that form the foundation of so much of what we build and do in the world.
- abtinf 7y agoThe world is held together with nothing but human thought. Man must be free so that his mind is free to think. A doctor working under compulsion should terrify those under his scalpel. Likewise for the engineer, and his customer, who designs a bridge, an elevator, or even a simple toaster.
- FakeComments 7y agoI’d say the better part of engineering is knowing how to design in the face of small errors creeping into the project.
- wging 7y agoDead comment reply by 'FakeComments' that I am not sure deserves to be dead (what happened there?): "I’d say the better part of engineering is knowing how to design in the face of small errors creeping into the project."
- deleted 7y ago[deleted]
- jorblumesea 7y agoIs anyone going to review their other bridge designs? Wonder what else they missed.
- abduhl 7y agoFIGG is one of the premier bridge designers in the country. You can probably get on one of their bridges within a couple hours no matter where you live.
- userbinator 7y agoIf I'm reading the report correctly, the bridge was barely sufficient to support its own weight, which is extremely surprising since I remember reading a very long time ago that bridges and other structures are designed to be 10x stronger than they normally need to be; a vague reference in the article https://en.wikipedia.org/wiki/Factor_of_safety https://en.wikipedia.org/wiki/Factor_of_safety supports that. It seems like this bridge was designed for minimal cost...
- sitharus 7y agoThis is totally hearsay, but I've heard from multiple older engineers that as computer models have been improved over time the safety factor has been reduced as we have more accurate simulations. If the safety factors from the '50s had been used it's possible this bridge would never have been designed the way it was.
- dredmorbius 7y agoI've noticed from videos of recent bridge failures (FIU and the Taiwain Arch Bridge collapse a few weeks ago) how fast the failures occur. Contrast with, say, the Tacoma Narrows bridge failure in the 1940s. I suspect current designs are far nearer critical tolerances. Even under the ridiculous dynamics of the Tacoma Narrows incident, ultimate failure took hours.
- userbinator 7y agoEven under the ridiculous dynamics of the Tacoma Narrows incident, ultimate failure took hours. It took 4 months from construction to failure, during which time it was already flexing far more than normal.
- dredmorbius 7y agoThe FIU and Taiwan's Nanfang'ao Bridge collapse (https://en.wikipedia.org/wiki/Nanfang%27ao_Bridge https://en.wikipedia.org/wiki/Nanfang%27ao_Bridge) each precipitated in seconds. Contrast Tacoma Narrows, whose final throes were long enough for crowds to form and traffic to be cleared. Tacoma: https://youtube.com/watch?v=mXTSnZgrfxM https://youtube.com/watch?v=mXTSnZgrfxM FIU: https://youtube.com/watch?v=BSq8295GFk4 https://youtube.com/watch?v=BSq8295GFk4 Nanfang'ao: https://youtube.com/watch?v=mjsZbbG5fag https://youtube.com/watch?v=mjsZbbG5fag Morandi, Genoa, Italy: https://youtube.com/watch?v=_gEMep8xLHk https://youtube.com/watch?v=_gEMep8xLHk I-35W, Minneapolis, MN: https://youtube.com/watch?v=74JNl5n-YdI https://youtube.com/watch?v=74JNl5n-YdI
- harshreality 7y agoWhat 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 agoExpertise 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
- scarejunba 7y agoSo much for the much vaunted "Professional Engineers".
- jessaustin 7y agoAfter employing various PEs on various aspects of new buildings, I can't say I'm surprised. Never a straight answer when a convoluted one is available. Never a helpful creative suggestion. Rarely a thought for the needs of the end user. Rarely a plan drawing that clearly explains what contractors are supposed to do. Even worse, never a clear answer to the questions inevitably inspired by those inadequate drawings.
- jaclaz 7y agoYes, and (disclaimer: this is part of my job) often structural engineers have a very "narrow" view which summed up with the (as well often "narrow" views) of the architects, of the plant engineers and of other technicians/designers that are involved in a project create the need of a coordinator/facilitator that helps in the communication among these people, checks the (sometimes not-so-obvious) possible conflicting parts of the various drawings and "translates" the design for the contractor. Particularly lately I have seen an increase of (otherwise very good, smart and qualified) engineers and architects with no or very little on-site experience, that produce beautiful and valid drawings/designs that cannot be "as they are" realized in practice.
- civeng 7y agoAgree. Seems a PE should be required to have a few years experience in the construction field before they are licensed. So much friction in the process would be avoided if the professionals writing and drawing the instructions for a structure had actually performed the work, or physically seen day to day challenges prior to having responsible charge. Structural engineers would be less arrogant as well. I see this happening on a daily basis.
- abduhl 7y agoAs I’ve posted before, there’s nothing special about a guy with a PE other than him hanging out there with liability for the lawsuit. Someone with a PE license has met the minimum requirements from the state. Nothing else can be garnered from someone possessing a license. The minimum requirements have, historically, resulted in engineers who put out public facing designs that, more often than not, do not bring harm to the public. I can tell you first hand that sometimes the guy with a license who is actually at “the minimum” does not always put out something that is safe.
- natch 7y agoThe engineering firm mentioned as responsible in the report hosts their web site without using https: http://www.figgbridge.com http://www.figgbridge.com Why am I not surprised?
- ars 7y agoWhy exactly should they care? Is there something secret on their site? A login form perhaps?
- natch 7y agoThey should care because https is not just about protecting secrets. Thinking that is the case is a common misconception about https. Among other things having https also makes it harder for a bad actor to deliver false content while intercepting requests to the site.
- corebit 7y agoAnd pointlessly makes it harder to deliver true content in the first place. Not everything needs to be HTTPS.
- Animats 7y agoA fake cable-stayed 175-foot span pedestrian bridge for $9 million. For less money, they could have had a real cable-stayed bridge, like the one over I-280 near Apple HQ.[1] That cost $14 million, but it's a 375-foot clear span over the freeway. [1] https://en.wikipedia.org/wiki/Don_Burnett_Bicycle-Pedestrian_Bridge https://en.wikipedia.org/wiki/Don_Burnett_Bicycle-Pedestrian...
- stevenwoo 7y agoiirc all the bids for a concrete version (ala Florida) were twice as much for the steel design that was used, otoh California version also has to be earthquake resistant. I gotta give credit to all the engineering firms and Caltrans oversight. Very little downtime on 280, that would have been a traffic nightmare for entire peninsula.
- OrangeMango 7y ago$14 million for 375 feet in CA is ~$37k/ft A 620 ft concrete suspension bridge [1] in Chicago was $23 million, or ~$37k/ft A 1470 ft concrete and steel bridge [2] in Chicago was $33 million, or ~$22k/ft This ugly monstrosity in Florida was $9 million for 174 feet, or ~$51k/ft It's awfully pathetic. [1] https://www.exp.com/project/35th-street-pedestrian-bridge/ https://www.exp.com/project/35th-street-pedestrian-bridge/ [2] https://chicagocrusader.com/new-41st-street-pedestrian-bridge-in-bronzeville-opens/ https://chicagocrusader.com/new-41st-street-pedestrian-bridg...
- masonic 7y agoIt's also little used, partially because it's a handy venue for violent crime due to lack of patrol or surveillance.
- CommieDetector 7y agoIt was designed by an all female politically connected feminists. Get woke, go broke.. this time it was Get woke, kill people due to incompetence.
- yumario 7y agoI study at FIU... I just don't see the point this bridge. Why would you spend 10+ million dollars on a bridge to cross a street, when the same problem can be solved by a simple crosswalk? We already have one of these bridges... and the majority of people don't bother to use it and simple take the cross walk. It just such a waste of money.
- juliusmusseau 7y agoYou clearly don't study any subjects in the fine arts. :-p
- Mountain_Skies 7y agoThe federal government was picking up most of the cost. It's much easier to be wasteful when it comes out of someone else's budget.
- baud147258 7y agoAnd when it also supports your claim of being at the bleeding edge of bridge construction.
- ciabattabread 7y agoBecause drivers want to go 60mph and not wait at stop lights for more than 3 seconds.
- userbinator 7y agoI'm not sure about that area, but pedestrian bridges are safer and more efficient, especially when traffic is heavy.
- elteto 7y agoTo put it into perspective, 8th street is an 8 lane street at that intersection, with cars driving past 50 and 55 mph all the time. Not to mention that there are several on/off ramps for the Florida Turnpike right next to it. I would be scared of crossing the street there to be honest. If I remember correctly there had been several hit and runs of students too. The bridge was connecting FIU with a large student residence. Negligence during construction notwithstanding, to say that a simple crosswalk was enough is disingenuous.
- campfireveteran 7y agoRecent NTSB video: https://youtu.be/hBjntrebxj8 https://youtu.be/hBjntrebxj8
- alexhutcheson 7y agoThe Miami Herald has done some great reporting on this: https://www.miamiherald.com/news/local/community/miami-dade/article236250848.html https://www.miamiherald.com/news/local/community/miami-dade/...
- deleted 7y ago[deleted]