genoa bridge collapse: the road to tragedy - touch screen guitar

James Granz, Gaia Piani, Jeremy White, and Kartik patanghali
2018 Genoa, Italy-An off-
On duty firefighter Davide Capello had just driven out of the tunnel in a heavy rain, boarding the main bridge over Genoa, and he heard a deep and dull rumbling around the car.
Not thunder. Mr.
Capello, 33, glanced up and saw a large white dust rising in the fog and rain.
A white car 20 or 30 yards in front of him seemed to disappear into a blank.
He stepped on the brakes.
But as the road fades away, the emptiness comes to him like a forgotten staircase.
In a flash his car went straight down, his nose went down, and the windshield flew past him by dust and concrete blocks. “I am dead! I am dead! ” he cried.
He fell free.
On the day of August, the bridge he was driving, a viaduct designed by Riccardo Morandi collapsed.
The month left 43 dead, many cars on several 150 feet river beds, railway and tenacious streets.
Collapse of the bridge-
The signs of the port city, the source of deep civic pride, and the indispensable daily traffic ties of thousands of people
Scarred Genoa and sparked a heated debate in Italy about who was responsible for the disaster and what caused it.
The chief magistrate of the region, Francesco Cozzi, and a team of engineers, security and government officials are still investigating these issues.
The New York Times used investigators to describe an important piece of evidence to reproduce what happened --
Video taken by a security camera.
About 5 miles to downtown kenona about 30 miles to downtown Savona about 5 miles to downtown Savona about 30 miles to run nearly 150 feet on dry river beds and railways.
The cable in the south of the bridge broke, causing the cable to suddenly relax.
The section began to tilt South.
As the part of the road begins to break, the weight of the road falls completely on the pillar of the North . . . . . . The remaining cables and concrete pillars are also broken.
When the road debris falls to the ground, the broken end of the pillar hangs at the top of the tower and some land vertically.
The last nearly 300-
The Foot tower collapsed in the center of a pile of rubble.
The initially relaxed southern bracket is the same as the corrosion or other disturbing signals found by Carmelo Gentile, a structural engineering professor at Milan Polytechnic University, during a test conducted in last October.
He warned the company that managed the bridge, the Italian highway company, but he said his suggestion was to conduct more comprehensive computer research and install permanent sensors for the bridge, but this proposal has never been implemented.
"They may have underestimated the importance of information," Professor Gentile said in an interview . ".
Autostrade never denied Professor Gentile's findings, but said no one was aware of any urgency.
In a statement this week, Autostrade said that Professor Gentile's proposal was incorporated into the Viaduct renovation proposal approved in June, but accused the Ministry of Infrastructure of delaying the authorization of the work for several months.
The footage taken by the security camera has not been reported in detail before and has not been made public.
However, the two senior members of the investigation described the situation to the New York Times, including a member of the Genoa financial police, under the command of Col.
Filippo in Ivan in than Shaw people.
Interviews with dozens of rescuers, investigators and expert engineers, as well as inspections of drone and helicopter footage and the ruins themselves, can sketch the collapse from beginning to end.
Because the investigation is still in its early stages, it is still possible to change the conclusion.
For example, failure that is not visible in the roadway structure or the shift of the tower base may cause a failure of the pillar.
Further work remains to be done to eliminate this possibility.
Still, Mr. rumble.
According to Professor Gentile, Capello has heard that this is likely to be the initial fracture of the steel inside the bracket that he warned.
Unless further evidence appears, says Vijay K.
Saraf is the chief engineer of Exponent, an infrastructure and construction consulting firm in Menlo Park, California.
, "Everything you have is consistent with the failure of Southern accommodation.
"From this point on, with the dynamic, thousand
Professor Gentile said the bridge did not have the opportunity to remain upright due to the large load on the remaining structures.
The video shows that the rest of the bridge also took no more than three or four seconds to carry the extra weight.
"It is impossible to save the bridge, but perhaps it is possible to save the people who died in the collapse," he said . ".
The viaduct in Genoa was built in the 1960 s, not just a bridge. It was a 3,600-
The walking tour of art and innovation, attracting its designer Riccardo Morandi, has a high reputation in architecture and engineering around the world.
Its figure is so light and airy that it seems to jump from the elegant lines on an engineer's grid pad to the deep and undulating valley of Genoa.
The signature element is three narrow,-
Frame tower up nearly 300 feet, paired with only 12 accommodations-
Stand that extends from the tower and is fixed on both sides of the road to support it.
Marzia Marandola said that even in a country with countless historical buildings, it has become "one of the most important bridges in Italy," a part-time professor of architectural history at the University of Sapienza in Rome, an expert at Mr. Morandi’s work.
The building "provides identity for the site and for the whole area," she said ".
"It managed to be part of the landscape.
Its beauty lies in its simplicity.
But engineers have come to realize that there is little important support for this structure. if one of the supports fails, the whole structure may collapse.
Massimo majowieki, architect and engineer at Bologna in northern Italy, said: "There is no robustness, and there is no possibility of redistributing troops . ".
The lack of redundancy, as is often now called "not necessarily inconsistent with the design of bridges in the 1960 s," said Donald duchenbury ", A structural engineer at Simpson gumpez and geg in Boston.
For this reason, the design is "hard to criticize ".
Dusenberry said although he said it was extra for inspection and maintenance.
Andrew Herman, a structural engineer and former president of the American Association of Civil Engineers, described the danger in the clearest terms.
"If you lose a stay ,"
Herman said: "The whole thing is over.
These concerns are far from theoretical, especially his other concerns.
Morandi's innovation is that he hangs the roadway from the stand, essentially tying the cables together and being wrapped in what is called a prestressed concrete shell.
In concrete.
Outsourced steel cables inside concrete keep prestressed concrete
Outsourced steel cables inside concrete keep prestressed concrete
He believes that the use of the system will reduce the swing of the bridge.
The structural engineer seems to agree. But Mr.
Morandi also believes that the concrete coating will protect the steel cables inside from the wear and tear of the components.
"The concrete structure seems to be eternal . "
Said Marcho wiki.
"This is a mentality.
It is for this hope, he added.
Moranti was wrong.
It turned out that the concrete at that time was very vulnerable to degradation, which could have been exacerbated by the salty air of the Mediterranean and the harsh smoke from nearby factories.
The cracks in the concrete shell let the water in, and the steel bars began to corrosion almost after the bridge was opened in 1967.
But unlike bare cables, any corrosion is hidden deep inside and it is difficult to detect.
By the end of 1970, the concrete on the bridge had begun to deteriorate significantly, forcing
Morandi died in 1989, defending his creation.
In 1979 and 1981, sir.
Morandi himself investigated the bridge and concluded that the roads and elements of the tower had been degraded.
The findings have caused panic around the world about buildings like Morandi.
Comparison between Morandi Bridge and modern cable
Xiangfu bridgescrete-
If one stop fails, the bridge is more likely to collapse.
Tensioncompressionbuilder support load-
Bearing towerMORANDI BRIDGEModern cable
The Stayed Bridge uses more stays, so the failure of stay is unlikely to affect the structure of the bridge.
Steel scompressionforce load-Steel cable
Modern cable-
Bridgetown Crete hotels
If one stop fails, the bridge is more likely to collapse.
Tensioncompressionbuilder support load-
Bearing towerMORANDI BRIDGEModern cable
The Stayed Bridge uses more stays, so the failure of stay is unlikely to affect the structure of the bridge.
Steel cable under pressure
Modern cable-
If one stop fails, the bridge is more likely to collapse. Concrete-
Encasedcable staystensionforcescompressionforcespier supportsload-
Bearing towerMORANDI BRIDGEModern cable
The Stayed Bridge uses more stays, so the failure of stay is unlikely to affect the structure of the bridge.
Steel cable under pressure
Modern cable-
David Goodyear, chief bridge engineer at T. , said that all brackets on a bridge similar to Morandi in Venezuela were replaced by cables with protective sheaths, but no concreteY.
Lin International, San Francisco engineering services.
In the 1990 s, the easternmost corrosion and other problems of the three towers on the Genoa bridge became so serious that their brackets were similarly renovated.
For reasons not fully explained, the Autostrade, which took over the management of the bridge in 1999, did not perform the same operation on the stand of the other two towers
Including the tower that collapsed.
But Autostrade expressed sufficient concern about the apparent deterioration of the bridge, which in last October asked Professor Gentile to test possible hidden damage inside the concrete.
When it comes to bridges, Professor Gentile is the closest musician to structural engineers.
He listened to the sound of the bridge.
From these sounds, he judged whether the bridge was safe or not.
Placing small devices in different locations, he has tested around 300 bridges around the world.
Each part vibrates like a guitar string: a higher load on the element, like a tighter string, produces a higher frequency;
Larger elements, such as thicker strings, produce lower notes.
In addition to the frequency, Professor Gentile also tested whether the vibration has the same smooth, predictable wave
Just like those cute notes that would make on the violin.
Consistency represents integrity.
Work must be accompanied by further research when sound is not harmonious, often involving computer models to determine exactly what the problem is.
On the four nights of last October, Professor Gentile recorded the frequency of Morandi Bridge.
Professor jantilly said that most of the accommodation on the two towers he tested sounded good.
But he found that the two towers in the South seemed wrong.
They're like damaged strings.
He said he suspected that the cables hidden inside the concrete were corroded, that there was some problem with the point where the brackets were connected to the Tower or the roadway, or that there was a problem elsewhere in the structure.
Of course, he advised the bridge to be permanently equipped with sensors and to conduct additional research to determine the cause of what he called an "anomaly" finding.
The Autostrade subcontractor in charge of the work never contacted him after the contract expired on October.
Professor Gentile said.
Autostrade, who handled media enquiries on behalf of subcontractor Spea Engineering, declined to comment.
According to Italian news reports, Autostrade has never given any specific warning to the Ministry of Infrastructure about the Genoa viaduct.
Police investigators, however, told the New York Times that the company's manager exchanged information weeks before the collapse noting "criticism" on the bridge.
But officials say it is not clear what the company manager is specifically referring to, nor how well Autostrade knows the true state of the bridge.
The company also said it "quickly fulfilled its promised concession obligations", including the maintenance of the bridge.
However, the maintenance costs around Genoa, due to its aging infrastructure, are on average twice that of the rest of Italy and four times that of bridges, viaduct and overpasses, according to the company documents published on their website after the bridge collapsed.
Now, Italy has had a heated debate about whether the company has done enough --
In addition, a call was made to remove the privatization of most of Italy's roads.
Autostrade won a cash concession to run nearly half of Italy's highways
The Italian government has been in trouble since 1999.
After that, there was no major renovation of the Morandi Bridge.
At the end of 2017 or at the beginning of 2018, tests showed that the bridge had been "on average" weakened by Roberto ferranza, head of the local infrastructure and transport department, by 10 to 20%, told The Times in an interview.
Bridge construction experts say it is well known that it is difficult to measure the exact amount of degradation of steel bars buried in concrete as it was on the Morandi Bridge.
"Nothing is more accurate than trying to assess the condition of the internal cable," Gary J. said . "
Klein, a member of the National Institute of Engineering, studied structural failure and served as executive vice president of engineering and construction company Wiss, Janney, Elstner, Northbrook, NY.
"This is a very imperfect science.
Because the weakest place may be anywhere in the structure.
Klein added, "You have to be in the right place at the right time, so I am very skeptical about the accuracy of any such estimates.
"Autostrade has made a decision based on the basic towers department to renovate and repair accommodation on both towers, including those that will collapse.
But the work has not been arranged yet.
An ongoing minor repair, two years ago Antonio brencic, an engineer at the University of Genoa, wrote a paper suggesting the replacement of the entire bridge.
In a short interview near the ruins of the bridge,
Brencich, a member of the team investigating the collapse, said it was like having a car that needed constant repair --
At some point it makes more sense to buy a new one.
But it will be expensive.
After the Morandi bridge collapsed, Italy's new populist ruling coalition immediately blamed Autostrade for the disaster and for the company's poor maintenance. The anti-
In particular, the five-star sports company threatened to revoke the company's contract and impose a fine of hundreds of millions of euros. But their far-
The right partner in the alliance, led by Deputy Prime Minister Matteo Salvini, is more cautious.
When it was still named the Northern League, the party got 150,000-
The euro donated by Autostrade to other political parties. In 2008, Mr.
Salvini and his northern coalition voted in parliament to extend the licence to Autostrade.
Once the road below him falls, sir.
Capello did not know how long he had fallen. Or how far.
In an interview with The Times, he said he thought he must have died.
The fall broke his back window.
He touched his head and neck and felt blood.
He also checked his hand.
He was also wearing a tight seat belt and rubbing his neck.
He's fine, but he needs help.
The rain outside kept going underground, making a mess.
A truck on the bridge landed on the road below, blocking traffic.
It carries hundreds of water bottles everywhere.
"Trying to get to the scene is like walking on a soap," said Sergio orcese, one of the first firefighters to arrive.
Some cars were still lying on the road on the bridge, but were crushed by heavy pieces of concrete that had rained, and it was even difficult to discern their models.
Some of them were swayed with steel cables.
A few trucks parked in the field on both sides of it, after a month-
Flying from the yard on the bridge
There is a smell of gas in the air.
But the heavy rain wet the dust of Concrete Powder.
Some people remember the terrible silence. some people remember the firemen shouting. Mr.
Olches heard a mother calling for her daughter, who was buried alive under the rubble. “Camilla! Camilla! She screamed.
"She begged us to save her daughter's voice first, the only voice I remember on the bridge," he recalls . ".
His team dug and moved more than an hour and a half of concrete blocks to release the girl and her mother lying on the top of the pile where her daughter was buried, holding her hand
He said the firefighters were exhausted when they managed to rescue the living women from the rubble.
"It's a war scene," said Maurizio Volpara, an experienced fireman and team coordinator, who rescued him from a van hanging on a steel cable in the 25 yard air.
He said that the cabin of the van was facing the ground and was "bombed" by concrete blocks falling from the deck of the bridge ".
The young man trapped inside, his face pushed to the dashboard, screaming, "Come Pick Me Up, Please!
Get me out! ”Mr.
Walparra recalls people screaming everywhere
Some survivors fell off the bridge, rescuers, warehouse workers at the city garbage company next to the bridge, and finally residents.
"It rained heavily and it rained all morning," said Giuseppe Crosetti, another firefighter . ".
"Under the weight of the equipment, our boots sank down on the grass.
Residents help rescue workers deliver the heavy equipment needed to cut cars and release possible survivors. Inside Mr.
Capello's car is still playing on the sports radio.
He reached out to get the touch screen on the dashboard.
He then called the Italian equivalent of 911.
The line was busy, so he turned to one of his most frequent calls, his own fire station in the city of Savona, 30 miles west of Genoa.
"The bridge collapsed, I'm here, hanging on the level," he told his colleagues . ".
"I was between the eastern part of Genoa and the exit of the Western Expressway of Genoa, surrounded by cars everywhere.
He felt relieved when he knew the firemen were already on the road.
He dialed two more numbers.
"I'm fine," he told his girlfriend, who had just been with him for an hour before filling up the tank and leaving for Genoa.
"The bridge collapsed, but I'm still alive. Don't worry.
I have no scratches. ”Mr.
Capello's fiance couldn't believe it, he said. “What bridge? ” she asked.
He had to cut her short.
He also wants to reassure his parents that he knows he has to get off as soon as possible.
"I'm afraid I won't hear them anymore . "Capello said.
When he called him, his father was a retired fireman who served for 30 years, and he told him: "Get off at once!
Then he heard a young man screaming outside.
"Is there anyone in there? ”“Help me! I am here,” Mr.
Capello replied, unfasten the seat belt and climb over the seat from the broken rear window.
"Leave there," shouted a policeman . ".
He is on a pile of ruins.
The young man who called him was a local resident. he helped him climb down.
"When I left, I looked back and the bridge was gone," he said in a trembling voice.
"It was not until then that I realized the seriousness of the disaster.
"The onlookers looked at him unbelievably, and he said he walked away in a blue rain-proof jacket with the Italian flag, gray shorts and white sneakers sewn on it, soaking wet.
"They looked at me as if I were a ghost," he said . ".
Source: Financial Police of Genoa;
Italian security officials; Vijay K.
Saraf, chief engineer, Exponent;
Italian national fire department made by Andrew rosback.
Additional work for Anjali Singhvi.
Source: Financial Police of Genoa;
Italian security officials; Vijay K.
Saraf, chief engineer, Exponent;
Italian national fire department made by Andrew rosback.
Additional work for Anjali Singhvi.