At least 43 people were killed when dozens of vehicles fell 45m (148ft) from the Morandi bridge in Genoa, Italy, during a storm on Tuesday 14.8.18 with cars and trucks buried under the rubble.
The authorities immediately dispatched emergency service personnel in order to rescue people from under the wreckage as a major rescue operation, which is still continuing, got underway. Officials have warned that the scale of the disaster was such that the toll was likely to rise.
Here’s what we know so far
The Morandi bridge carries a major road, the A10 toll motorway, which serves the Italian Riviera and links northern Italy to France. It was designed by Riccardo Morandi who also designed the much larger Lake Maracaibo bridge in Venezuela.
The 1.2km (0.8 mile) long bridge spans the Polcevera waterway, railway lines and various industrial buildings. The bridge was completed in 1967 with restructuring work being undertaken in 2016. Major repairs were also carried out in the 1990s. Work to shore up the bridge's foundation was being carried out at the time of the collapse, during which time it was being constantly monitored.
A section of the bridge measuring about 200m fell at approximately 11:30 local time (09:30 GMT) during a violent cloudburst. The bridge collapse is the second major accident in Italy this month, following a fuel truck explosion near the Bologna airport last week. It was also the fifth bridge collapse in Italy in five years.
At present it is not clear what caused the disaster, but a range of possible explanations have been put forward...
Some experts have suggested that the ongoing maintenance work may have been a factor in the collapse. It has also been suggested that the collapse may have been caused by a design flaw or heavy traffic.
Speaking to WAN about the bridge collapse Ian Firth, a structural engineer and specialist in bridges, said the Morandi bridge had a very unusual design. “It is too early to say what caused the tragic collapse, but as this reinforced and pre-stressed concrete bridge has been there for 50 years, it is possible that corrosion of tendons or reinforcement may be a contributory factor. The list of maintenance interventions suggests the structure may have had difficulties in the past. The cables are completely clad in concrete which is very unusual. No one would have known the condition of the tendons because they are not visible inside the concrete structure. It is interesting to note that new cables have been added at the end opposite to the collapsed section, suggesting that there was an issue there recently.” He went on to say: “Bridges of this nature require regular inspection by Bridge Engineers and this seems to have been carried out.”
The bridge carries 25 million vehicles every year, and a 2011 report by an Italian highways company said that the bridge had been suffering from degradation.
The Italian structural engineer Antonio Brencich wrote in 2016 that it may have been more economical to rebuild the bridge because of the ongoing maintenance costs. Brencich was quoted as saying: "There are errors in this bridge. Sooner or later, it will have to be replaced. I don't know when."
Corrosion of the concrete in the bridge will undoubtedly be an issue that is focused on by investigations. The bridge was constructed using reinforced and pre-stressed concrete. There are a large number of reinforced concrete bridges in Italy, Europe, USA, and Canada of the same age, which are suffering from corrosion of reinforcement and pre-stressing tendons. In addition, wind and earthquakes can gradually put fatigue on bridges but it is too early to say if this affected the Morandi bridge.
However, the extreme local weather conditions on Tuesday may have contributed to the collapse. Regional weather services had issued a storm warning for the morning of the incident and the national police force said on Twitter the disaster happened amid a "violent cloudburst".
The response to the collapse
Interior Minister and Deputy PM Matteo Salvini said the disaster showed that Italy needed to spend more on infrastructure despite European Union budget constraints.
"We should ask ourselves whether respecting these limits is more important than the safety of Italian citizens," he said.
He added that he was committed to finding those responsible for the "unacceptable disaster. I will do everything to get the names and surnames of the managers responsible, past and present," he said.
Italian Transport Minister Danilo Toninelli has called for resignations at the Italian highways agency which operated the bridge. "The top management of Autostrade per l'Italia must step down first of all," he said on Facebook.
There have been four more significant bridge collapses so far this year…
- Chirajara Viaduct in Columbia. 15 Jan 2018.
Cable-stayed bridge.10 Construction Workers killed, about 6 injured. Total collapse of half bridge. Remaining half likely to be demolished. Bridge failure is being investigated by the Mexican company Mexpresa, and American company Modjeski and Masters
- Florida International University pedestrian bridge in Miami, USA. 15 March 2018.
Concrete Pedestrian Bridge. At least 6 dead, 10 others injured. Partially constructed concrete truss bridge with faux cable ties. One of two spans erected without faux cable ties or support tower. Exact cause yet to be investigated.
- Pathein – Chaung Thar Bridge in Myanmar. 1 April 2018.
Concrete Steel Suspension Bridge. Two dead. Built 2004, 60 ton specification was reduced to 20 tons, when a 6 wheels truck crossed at mid-night, 1am the bridge broken half. Suspected steel rode. Exact cause yet to be investigated.
- Zhejiang Bridge. 28 July 2018.
Eight dead. Viaduct incorporating a cable-stayed bridge