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.

 

[cooperDBM]

Structural weakness versus structural instability is a meaningful distinction. Don't know if they're right here. Was it a cable-stayed bridge? The video seems to show a tower collapsing.

 

[bimr]

On 14 August 2018, a 200-metre (660 ft) part of the Ponte Morandi crossing the Polcevera stream and an industrial area of ​​Sampierdarena (a major port and industrial area of Genoa in northwest Italy) collapsed during a torrential rain storm. Approximately ten vehicles were reported to have been on the collapsed span. The initial hypothesis formulated is that of a structural failure. Dozens of people are reported to have been killed in the collapse; at least 35 deaths have been confirmed so far. A large part of the collapsed bridge and the vehicles on it fell into the flooded Polcevera, while other fragments landed on top of railway tracks and warehouses. The bridge was reportedly undergoing maintenance at the time of the collapse.

"The highway operator said work to shore up the foundation of the bridge was being carried out at the time of the collapse, adding that the bridge was constantly monitored. According to a source, "work was underway to consolidate the viaduct slab and, as planned, a bridge crane had been installed to allow maintenance activities to take place".

"Restructuring work on the bridge was carried out in 2016."

 

[cooperDBM]

If it's the Autostrada del Fiori it's a cable stayed bridge with A frame towers.

from Google Streetview

https://www.google.com/maps/@44.424...=203&h=100&yaw=210.97716&pitch=0&thumbfov=100

https://www.google.com/maps/@44.424...4!1sQAt4gEhLxx56y0JyO810Bg!2e0!7i13312!8i6656

 

[Pete_K]

I found this note about the designer:

"...a rare type of cable stayed bridge that uses prestressed concrete stays instead of conventional wire strand stays. Morandi developed this unique type of stay as an extension of his skill with concrete and how it could be used in unusual ways."

 

[cooperDBM]

Looks like the west tower collapsed which seems to be beside a floodway.

An old video of the floodway,

https://www.youtube.com/watch?v=dbDnFNjGlkw

 

[3DDave]

It's interesting how isolated the failure was - not cascade failure to the other segments of the bridge.

 

[cooperDBM]

3DDave, the bridge probably has expansion joints isolating the portion of deck supported by each tower, and the approaches.

 

[bridgebuster]

Another story from Roads and Bridges magazine

Link

 

[thebard3]

Built in 1967, if the design was a contributor to the collapse, so certainly was in part due to the maintenance work. The original cited article now says 22 confirmed dead.

Brad Waybright

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

 

[JohnRBaker]

From the linked item in the post by bridgebuster above:

"...after a section of a highway bridge in northern Italy partially collapsed Tuesday,..."

How can someone possibly use the term "partially collapsed" right under that photo:

And they can't claim that they were saying that only part of the bridge had collapsed since they had already qualified their claim by saying that "a section of a highway bridge". Just poor reporting or poor editing, take your pick.

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[JStephen]

Poor wording, it happens. Reminds me of overuse of "alleged".

"Structural weakness" sounds like overly obvious wording, but then again, that meant they weren't suspecting sabotage or terrorism, it didn't get hit by a plane or a ship, etc.

 

[BridgeSmith]

"The initial hypothesis formulated is that of a structural failure."

Uh yeah...that would be a given, wouldn't it, unless something big hit it, which no one has suggested?

 

[John R]

Interesting photos here: Scroll down

https://www.thehulltruth.com/dockside-chat/953706-bridge-collapse-genoa-italy.html

 

[ImminentCollapse]

Interestingly, if you go to Google street view and ride across the bridge, the S/E span has external P/T strengthening up the length of all four concrete stays. The other main spans do not including the one that collapsed. There was work going on the north side at the deck level, but it looks like barrier rail work so may be unrelated.

IC

 

[TenPenny]

On one report I heard on the radio, there was mention that this bridge has been a problem pretty much since it was built.

Also mentioned in that report was that about 30 bridges collapse in Italy EVERY YEAR. Of course, many are small and unremarkable, but still. 2 to 3 bridges per month?

 

[JAE]

A unique framing system for sure based on some photo views from under the bridge:

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[Heldbaum]

Around 5 years ago, in Venezuela in one of Morandi's bridge main cables were replaced because there were concerns about its condition... Morandi's cables were covered with concrete that was a corrosion protection so there was no way to monitor the corrosion progression.. It looks like they should have done the same in Italy

 

[JAE]

I don't think the cable-stayed part of this bridge fell down - it was the first pier beyond the end of the cable stays that appears to have failed - or the deck just adjacent to that pier.

From the photo posted by bimr above, the two cable-stay assemblies are still standing.

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[thebard3]

JAE, there were originally 3 towers, according to the pictures I have seen. One of them fell. Of course, It could have been a number of failures not associated with that tower. Preliminary reports say there was 'shoring' being done, and a tower crane was employed for maintenance work, but I haven't seen any evidence of a crane yet.

Brad Waybright

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