Another bridge has collapsed and it could have been avoided. Well, that is what at least one engineer thinks. This one came down near Genoa in Italy, just this week. Euronews reports that an engineering professor, back in 2016, had urged the authorities to ‘completely rebuild’ the Morandi Bridge because of deterioration.
On the 14th of August 2018, the bridge came plummeting down causing at least 35 fatalities. And many more are feared missing. In total, 200 meters of the 1.1 kilometer bridge plunged 50 feet taking cars and trucks down with it.
Antonio Brencich, a professor of engineering at the University of Genoa told ingengneri.info:
“The continuous costs for its maintenance suggest that in a few years, these costs will exceed the costs of reconstruction of the bridge; at that point it will be the time to demolish it and rebuild it.”
The bridge, which was constructed in the 1960s, provided a link between France and Rome. It was engineered by Riccardo Morandi, who was renowned for his work with reinforced concrete. While it's a cable-stayed bridge, it utilizes reinforced concrete for the cable stays instead of regular cables.
The lifetime of the bridge was supposed to be 100 years, but Brencich alleged that the east tower of the bridge was not appropriately reinforced. It was, however, the west tower that seemed to give way.
Autostrade del Tronco Genovese, the maintenance authority responsible for maintaining highways and bridges, says that the bridge’s recent checks did not indicate that it was in imminent danger. Recent torrential rain in the area is being considered as a contributing factor to the bridge’s collapse. Other online commenters say that the bridge may have been struck by lightning.
A Genoese architect Diego Zoppi speaking to the ANSA news agency said:
“The problem with the Morandi Bridge is that the tie rods were made of concrete and not metal. In the 1960s they did not expect concrete to degrade and then collapse. Fifty years ago there was unlimited confidence in reinforced concrete. It was believed to be eternal. With the continuous vibrations of traffic, the cement cracks let air pass through, which reaches the internal metal structure and makes it oxidize. For this reason, the bridge has always required extensive maintenance work. It was very expensive to manage.”
The concern now is for other structures dated around the same time as the Morandi Bridge. These will need to be scrupulously checked for any signs of wear and tear, to prevent similar accidents.
Further focus will be given to the loads that the bridge endured over the years; the level of fatigue it had experienced could have been significant. Mehdi Kashani, associate professor in structural mechanics at the University of Southampton, talking to the Independent said:
“The bridge engineering research community should take this seriously in their future research to improve the resilience of our infrastructure under extreme loading.”
Engineering experts say it is too early to confidently attribute cause to the collapse of the Morandi Bridge, but point to the fact that corrosion of the reinforcement in the concrete is a likely explanation. What remains clear is that regular maintenance for bridges should be enforced, and attention paid to experts who indicate that structural issues exist.
Fiorentino, Michael. “Engineer Warned in 2016 That Genoa Bridge Would Need Rebuilding.” Euronews, 14 Aug. 2018, www.euronews.com/2018/08/14/engineer-warned-in-2016-that-genoa-bridge-would-need-rebuilding.
Griffin, Andrew. “Experts Weigh in on Shocking Italian Bridge Collapse.” The Independent, Independent Digital News and Media, 14 Aug. 2018, www.independent.co.uk/news/science/genoa-bridge-collapse-italy-why-did-disaster-engineering-experts-a8491811.html.