Bridge Collapse in Genoa, Italy 26

[thebard3]

https://www.cbsnews.com/news/italy-...noa-traps-cars-under-rubble-today-2018-08-14/

An interesting theory from the article: "Italian news agency ANSA said authorities suspected that a structural weakness caused the collapse".

Brad Waybright

It's all okay as long as it's okay.

 

[BridgeSmith]

"As such, it is most likely that the column failure was a result of some other issue, rather than the root cause."

Most likely a result of the large moments generated by failure of other components, which the column was not designed or expected to carry.

 

[thebard3]

Sorry guys, I wan't really suggesting that this failed first or that a lack of rebar was to blame, I'm just used to seeing something more like this:

.

Brad Waybright

It's all okay as long as it's okay.

 

[miningman]

Gotta make the observation that regardless of root cause, be it poor design , inadequate maintenance or substandard construction techniques, its ironic that Roman structures 2000 years old are still standing, as are British cathedrals still very much in daily use 1000 years after construction, and we have reached the situation that critical infrastructure fails in 30-50 years. As a society we arent doing really well are we

 

[JStephen]

That's kind of deceptive, because the Roman structures that are still standing are few and far between, most of them are long gone, as are many of the cathedrals. Come back in 2000 years, and if we haven't torn it down, you'll see the remnants of an overpass here or there...

I recall seeing a while back an article on why Roman concrete was so long-lasting, but don't recall the details.

Also, keep in mind that structurally, things tend to fall into a pile, and the closer your structure is to a pile in the first place, the longer it's going to last. So a pyramid is a big square pile, and it's there for the duration. Burial mounds here and there are still around. Structures that are basically heavy things stacked up- they're good if the earthquake isn't too strong. Other things- not so much.

 

[BrianPetersen]

Roman structures 2000 yrs old that are still standing have generally required, and received, a decent amount of caretaking and maintenance/repairs in order to do so.

That said, those structures were built before the era of steel reinforcement. Concrete is not fully impervious to water and air, and steel is quite obviously not resistant to corrosion if there is water and oxygen around. Therefore, anything made of steel-reinforced concrete in a climate that is not bone-dry has a clock slowly ticking away to its eventual failure.

I also recall reading that the volcanic ash that was part of the Roman concrete mixture had something to do with its durability.

 

[Vikko]

This is from google map. The west tower which collapsed was not properly reinforced so far as I understood.

 

[ImminentCollapse]

https://www.reuters.com/article/us-...-italy-bridge-stability-reports-idUSKBN1L210A

IC

 

[ImminentCollapse]

My text got cut off. Article on a study to look at the stays. So, they had already retrofitted the east span stays, had a report stating there was an "anomaly" in the subject span, and were working on a fix of some sort apparently. This is looking FIUish to some extent.

IC

 

[Spartan5]

I also recall reading that the volcanic ash that was part of the Roman concrete mixture had something to do with its durability.

They may have utilized geopolymeric cements.

https://www.geopolymer.org/archaeol...n-cement-and-concrete-high-durable-buildings/

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

 

[3DDave]

I think the failure to avoid this collapse was a result of knowing the exact problem source, but not the extent, and therefore not understanding the time frame needed to perform the repair. The FIU situation seems like no one understood the fundamental problem and the attempted fix made it worse.

Given the extent of spalling in the FIU bridge it's surprising they could get any workers on the bridge. The FIU failure seems very similar to the project management failure described in the 1907 Quebec Bridge failure where structural members were not behaving as expected but work progressed anyway.

https://www.thecanadianencyclopedia.ca/en/article/quebec-bridge-disaster-feature/

Other articles said a number of bridge workers had stopped showing up as the extent of the deformations increased.

It looks like it was well known that the Genoa bridges had a problem and it looks to me that the focus on repairs was to fix the parts that potentially endangered the most lives first.

I note the study head did not call for the immediate closure based on the results, just for further study. And that the bridge authority had already started the process of getting funding to make repairs on the now-failed span.

 

[bimr]

This is from google map. The west tower which collapsed was not properly reinforced so far as I understood.

In the case of the Genoa bridge, Occhiuzzi noted, some of the stays have been modified with clearly visible reinforcement, but the collapsed section was not modified. It is necessary to understand the background of the decision to reinforce some stays, but the same treatments have not been carried out on the other stays that are similar.

[URL unfurl="true"]http://www.ilsecoloxix.it/p/mondo/2018/08/15/ADxP1VAB-problemi_morandi_precedente.shtml[/url]

 

[bimr]

Gotta make the observation that regardless of root cause, be it poor design , inadequate maintenance or substandard construction techniques, its ironic that Roman structures 2000 years old are still standing, as are British cathedrals still very much in daily use 1000 years after construction, and we have reached the situation that critical infrastructure fails in 30-50 years. As a society we aren't doing really well are we

It is ironic that the Romans had some particularly disastrous failures too, like the Fidenae Amphitheatre. Perhaps one of the most shocking is the Fidenae Amphitheatre collapse, the earliest and the worst structural disaster in history. In 27 AD, according to Tacitus who provided the most accurate account of the event, “50,000 men were maimed or crushed in that disaster”.

 

[Comcokid]

Let's face it. Modern engineering knowledge allows an engineer to design and analyze to a great deal of accuracy and confidence. The Romans were good engineers, but didn't have the in-depth knowledge we have today. The Romans either seriously overbuilt (the Pantheon), adequately built (most structures) or under built (Fidenae Amphitheater example above). The Roman examples that are still around today technically by today's standards are failures - because they were overbuilt. Economics and accountants today would not permit such projects.

 

[hokie66]

Your definition of "overbuilt" differs from mine. That big concrete dome is completely unreinforced. That would be considered inadequate today.

 

[EmmanuelTop]

Root cause analysis should identify one, and one cause only, why the structure failed. When the media say "the bridge was 50 years old, it was not designed for heavy traffic, the maintenance was poor, and it was raining heavily that night, plus some guys were digging around the foundations" - that is all kind of fruit lumped together and it actually hides the principal cause. Which is what we all are interested in.

Dejan IVANOVIC
Process Engineer, MSChE

 

[SFCharlie]

One of the very first programming lessons I learned in 1965 was that if I found a bug in one part of a program, was to look for the same bug everywhere else in the program.

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[JAE]

So does Italy have any type of government agency that reviews collapses like this similar to the NTSB in the USA?
Just wondering if they ever publish reports as to "why it fell down"?


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[epoxybot]

JAE (Structural) - That is a good question. To Columbia's credit when investigating the Chirajara Stay-Cable Tower Collapse they did seek "private" international forensic help. Something more akin to Peer Review.

 

[robyengIT]

quote "JAE (Structural)19 Aug 18 22:44
So does Italy have any type of government agency ...?"
yes, there is, but ...! In the agreement between the highway Co. and the Government Authority it is stated that a Gov. Agency is enforced to control the maintenance investigations of the highway Co., but recently (2 years ago, approx)the Gov. Authority charged the highway Co. to control the controlling team : the controlled people have to control themselves !!
Furthermore the existing Government is looking for the possibility to cancel the agreement with the highway Co. (at least for that portion of highway) but in the agreement is stated that this is possible under a penalty of 10 billion of Euros (approx 11-12 billion U.S.A. dollars)

 

[3DDave]

Apparently the remaining sections of the bridge started making noise, so people who had been allowed back to collect some possessions from their apartments were ushered out.

https://abcnews.go.com/Internationa...dge-fatal-collapse-evacuees/story?id=57284782