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Abu Dhabi, UAESaturday 15 December 2018

Italy bridge designer warned in 1979 of risk of corrosion

A preliminary survey suggests a number of possible causes and not just a simple collapse of the bridge support

A section of the partially collapsed Morandi Bridge in Genoa. EPA
A section of the partially collapsed Morandi Bridge in Genoa. EPA

The Italian engineer who designed the Genoa bridge that crumbled to the ground killing 42 people had warned in 1979 of the need for constant maintenance due to pollution by a nearby steel plant, a report penned by him shows.

Riccardo Morandi, an Italian engineer renowned for his innovative use of reinforced concrete, had inaugurated the bridge in 1967. Twelve years later, he drafted a report in which he described his “perplexity” at the level of corrosion that was taking place in the Italian coastal town – a phenomenon he described as unlike any similar structures in different environments.

“Sooner or later, maybe in a few years, it will be necessary to resort to a treatment consisting of the removal of all traces of rust on the exposure of the reinforcements, to fill in the patches,” Mr Morandi wrote in the report.

While a nearby steel plant, as well as the sea air and the pollution levels, may have been responsible for accelerating the decay, engineers had called Mr Morandi’s design into question long before a stretch of its roadbed came tumbling down, pulling over 30 vehicles into the void.

Antonio Brencich, a specialist in reinforced concrete at the University of Genoa and one of six engineers appointed by the government to determine the causes of the collapse, told The National that maintenance work had been hampered by the nature of Mr Morandi’s design.

“Maintenance was taking place, but the bridge is designed in such a way that maintenance in certain parts is not possible,” Mr Brencich said.

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He pointed out that “fundamental parts” of the bridge could not be reached because of the way it had been built. “To access them you’d have to demolish part of the bridge. If you cannot access them, maintenance work cannot take place.”

Morandi had defended the soundness of his concrete bridge, despite highlighting a “well-known loss of superficial chemical resistance of the concrete.”

According to Mr Brencich, Morandi had used a technology he had patented for reinforced concrete but this was not used for other bridges as it was “a failure”.

A second bridge in Libya designed by the civil engineer is also thought to be currently at risk of collapse.

A week prior to the events in Genoa, the mayor of the Libyan town of Beida wrote to Tripoli’s government to denounce the imminent risk posed by the Wadi al-Kuf bridge, known as the “twin” of the Genoa bridge.

The commission of engineers tasked with examining the rubble will investigate the cause of the structural failure, including its design and the extent of maintenance works carried out by the motorway’s operator, Autostrade per L’Italia.

What is clear is that large amounts of money had already been invested on maintenance, which also meant that the motorway had to be closed to traffic during the night to allow for the work to take place. By the late 1990s, the amount spent on maintenance had already reached 80 per cent of the original construction cost.

A stretch of the Morandi Bridge stands as a woman pauses beside tributes left for the victims of those killed when a section of the bridge collapsed. Getty Images 
A stretch of the Morandi Bridge stands as a woman pauses beside tributes left for the victims of those killed when a section of the bridge collapsed. Getty

In a 2016 interview, Mr Brencich had warned that the bridge would not be economically sustainable and that it would be more convenient “to demolish the bridge and rebuild it.”

Despite its many problems, this stretch of the A10 motorway carried on functioning as the main route to France and to Milan, as well as a connecting bridge between the eastern and western parts of Genoa.

Plans to build a second motorway – which would have diverted part of the traffic, allowing for heftier maintenance to take place – was shelved partly owing to the political opposition of the Five Star Movement.

Its founder, the comedian Beppe Grillo, in 2009 sided with local residents who opposed big infrastructure projects in their neighbourhoods.

In a post to the M5S website – which was taken down after the tragedy – Grillo dismissed concerns that the bridge could give way, calling these warnings a “fairytale.”

A February 1 meeting of experts held earlier this year had also highlighted the advanced state of corrosion on the key bridge support. Roberto Ferrazza, the head of the government’s commission, had taken part in the meeting, after which experts had recommended that the supports be reinforced due to the “trend of degradation.”

Bidding opened in April for the 20 million-euro (Dh 84 million) public works contract to do the work, according to Italian media.

Engineers have long been concerns about its unusual concrete-encased stay cables, which Morandi used in several of his bridge designs instead of the more common steel cables.

Giovanni Castellucci, CEO of Autostrade per l'Italia, told reporters it has a plan to demolish what's left of the largely concrete 51-year-old Morandi Bridge and build a "less imposing" steel one in the next eight months.

Italy's president demanded guarantees Saturday that all the nation's roads are safe following the Genoa highway bridge collapse, after he hugged and comforted mourners at a state funeral in the grieving port city.

According to Mr Brencich, what happened in Genoa is a unique case and "should not be taken as a symbol of the state of Italian infrastructure."