Details still coming in but the 600 feet of bridge collaspe may have effects on train travel ? The google overhead showed the downed bridge crossing a small river, road, & a multi track rail line. Anyone know yet if the collaspe part has shut down the rail line ?
The last we heard was a bridge pier collasped during a big rain storm pulling down the section of bridge ? If so wonder if pier collaspe due to scouring ?
A real problem for the authorities to assess. It is probably not immediately obvious whether the weakness was inherent in the design, in which case the other segments are fragile, or whether it was damage or a flaw only in the collapsed portion. Obviously not a lot of redundancy in the structure!
Here is a photo of the intact Polcevera Viaduct: https://upload.wikimedia.org/wikipedia/commons/c/c6/Genova-panorama_dal_santuario_di_ns_incoronata3.jpg
And here one of the collapsed bridge. https://media1.faz.net/ppmedia/aktuell/1627041056/1.5737697/media_in_article_medium/54795030.jpg
The left pylon and the adjacent bridges are missing. If you look at the first photo you see less high bridges in both adjacent spans. These rest on the parts on bridge plates that are supported by the stays via gerber joint.
If these less high bridge plates collape, I'd expect no consequences for the collapsed pylon. But I could be wrong if the missing weight of the less high bridge leads to a large imballance that the pylon can not withstand.
Collapsed are the pylon with is stay supported bridges and two less high bridges.
The following video shows a bit unclear the pylon collapsing at 0:11. Interesting at that moment is, that the less high bridge is already missing. https://youtu.be/5NGbdpv1mSw
I only try to understand the structural design of the bridge and what happened.
There is no chance to say why it happened. There is too much information missing.
I don't think that the pylon foundation collapsed due to scouring. Here are photos of pylon's lower end. http://www.heute.at/2010/img/diashow_html5/1x1.gif http://www.heute.at/2010/img/diashow_html5/1x1.gifhttp://www.heute.at/2010/img/diashow_html5/1x1.gif
Looks like the pylon broke about 60'+ above the pier.Regards, Volker
Saw an over view of site. Appeared main RR line to east (?) not hit however no trains seem to be using that line presently. The collaspe appears to have fallen onto secondary RR lines to west(?} that may be freight lines. Believe observed some CAT down on that section.
Will not speculate but some eyewitnesses stated they saw lightning hit the bridge pylon ? Now if that is true and there was not suffiecient lightning protection on outside of pylon ? ? ?
blue streak 1Will not speculate but some eyewitnesses stated they saw lightning hit the bridge pylon ? Now if that is true and there was not suffiecient lightning protection on outside of pylon ? ? ?
I don't know if the bridge had a lightning protection system or if it is required in Italy.
A sound bridge would not be affected by lightnings. But even if it wasn't sound, which is likely, a lightning would not necessarily damage the bridge. The short answer, I don't know.
It is unlikely that the bridge was sound. It is 51 years old and needed strengthening of the stays at the first pylon already: www.e-periodica.ch/cntmng?type=pdf&pid=bse-re-003:1995:73/1:73/2::629
The stays are pre-tensioned concrete and quite vulnerable. We have a lot of problems with prestressing steel from that time in the German bridges. Not saying that it might have been the cause.
Here a picture of the pylon that collapsed: http://www.retrofutur.org/retrofutur/app/download/IMG_0180.JPG?DOCID=100002100&blobIndex=image_orig
Regards, Volker
Puts a spin on things - however, I would have expected the bridge piers to have been well grounded.
Never too old to have a happy childhood!
BaltACD blue streak 1 Will not speculate but some eyewitnesses stated they saw lightning hit the bridge pylon ? Now if that is true and there was not suffiecient lightning protection on outside of pylon ? ? ? Puts a spin on things - however, I would have expected the bridge piers to have been well grounded.
blue streak 1 Will not speculate but some eyewitnesses stated they saw lightning hit the bridge pylon ? Now if that is true and there was not suffiecient lightning protection on outside of pylon ? ? ?
I expect in such a bridge too. That there was nothing visible doesn't tell anything. In concrete structure you use either the reinforcement steel or strip steel 2''x1/4''.
In most cases it is the latter (at least in Germany) as using reinforcement means that the bars need to be electrically connected (welded). What I haven't seen are lightning rods on top of the pylons but the resolution of the photos might be not good enough to show. Electrical equipment and handrails will be protected.
For those who are interested I link a Spanish language technical report about the bridge. http://informesdelaconstruccion.revistas.csic.es/index.php/informesdelaconstruccion/article/viewFile/3892/4426
On page 9 and 10 are construction drawings. The report contains a lot of photos.
According to the drawings the pylons have pile foundation.Regards, Volker
Here is a pre collaspe picture of the bridge area. Note all the train tracks. Reports that these tracks are the main Italy - France RR connection.
https://www.cbc.ca/news/canada/toronto/canadian-students-avoid-italy-bridge-collapse-1.4784740https://www.cbc.ca/news/canada/toronto/canadian-students-avoid-italy-bridge-collapse-1.4784740https://www.cbc.ca/news/canada/toronto/canadian-students-avoid-italy-bridge-collapse-1.4784740https://www.cbc.ca/news/canada/toronto/canadian-students-avoid-italy-bridge-collapse-1.4784740
Read a report that the bridge was undergoing maintenance - whatever that is supposed to mean - the report mentioned that this particular type of design, which also has a sibling from the same designer built in Venazuela, have proven to be very maintenance intensive structures.
Morandi designed only three bridges with this type of stays. All needed permanent maintenance. No further bridges of this type were built.
The strengthening of the stays of the first pylon took already place about 28 years ago. A civil engineering professor at the University of Genova said in German TV that the bridge was not neglected but that it was under steady observation.
Not all developing defects can be detected easily from the outside.
I found the original video of the collapsing pylon: https://www.youtube.com/watch?v=9UyQB6QL2Rc
At very beginning is something I haven't seen when TV stations used it. In the first frame there is already a gap in front of the collapsing pylon. But at the next still standing tower is some part going down diagonally to the left that vanishes.
So the suspended span beteen tower and collapsing pylon breaks down before the pylon. But that doesn't help, as it could have started on the other side of the pylon. That part is not visible in the video.Regards, Volker
Volker======== Good questions. Did span fail first then pylon or maybe part of pylon failed and the span then rest of pylon ?
blue streak 1Volker======== Good questions. Did span fail first then pylon or maybe part of pylon failed and the span then rest of pylon ?
Currently everythings seems still possible. German experts have speculated about the collapse of a stay caused by breaking, corroded tendons. As the strengthening of the stays at the first pylon 28 years ago was caused by corrosion
It sounds like an educated guess but is nevertheless speculation.
The structure of the bridge with the suspended spans everywhere in between might have accelerated and aggrevated the collapse.
The statically determined parts of the bridge deck lead to a smaller safety margin than at a continous deck but were easier to calculate in times without computers.
Calculative the safety factor is the same for both structures. For a contious bridge deck to break, it has to develop the joint that are already built into the determined structure. Than the systems are really equal. But that is not considered in structural analysis or better has come into the equation about 15 years ago with better material knowledge.
While both structures might have a safety factor of 1.75, the real safety factor of the continous structure might be above 4.00.
A determined structure can collapse like a card house.Regards, Volker
Regarding the rail lines, the track on the near(west) leads south to the main freight yard(Genova Smistamento). If I have the bridge location correct this trackage leads north to the new low-grade line out of Genova(Genoa). The main passenger line crosses the river a little ways north of this bridge and so would be less affected except by worries about the condition of the remaining portions of the bridge. The line that stays on the east side of the river is the old line with a stiff climb of 2.9% of the coastal escarpment out of Genova. Very few freights use the old line. It is the mainline from Genova to Torino(Turin) and Milano(Milan), but High-speed trains do not run via Genova, and trains from Genova to Nice and Marseille hug the coast and shouldn't be affected.
Italian railways is having to cancel some trains but is also adding some shuttle trains to mitigate road congestion somewhat. Now can any of us think of any location that either Amtrak or a commuter agency could or would do the same ?
12 extra shuttle trains on the 15th and 24 extra shuttle trains on the 16th and for weekdays into the forseeable future.
https://www.railjournal.com/index.php/main-line/trenitalia-responds-to-genoa-highway-bridge-collapse.html?channel=000
For those who want to see the rail layout in Genova use the following link. You just keep zooming in. North of the port you will see the A10 road and believe it or not the map already shows the section of bridge missing !
Previous link had a mistake use this one
https://www.openrailwaymap.org/
blue streak 1For those who want to see the rail layout in Genova use the following link. You just keep zooming in. North of the port you will see the A10 road and believe it or not the map already shows the section of bridge missing ! Previous link had a mistake use this one https://www.openrailwaymap.org/
Between bridges and tunnels - A10 looks to have been a very expensive piece of contstruction.
BaltACD
Italy has awarded the contract worth €1.89bn to build the Brescia to Verona section of their High-speed network making a complete link across Northern Italy from Torino to Venezia.
Separately Italy has given up on its ambitions to upgrade their High-speed network for 300kph to 350kph.
Translated from corresponding German media (Die Zeit, Spiegel online; Tagesspiegel) reports:
Back in 1980 or so, there was a temporary rail shuttle service during a bridge outage in Phoenix. Amtrak equipment was used, but I don’t know if they were the actual operator.
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