New Genoa Bridge Deck Placement Begins
Earlier this month, over a year after the collapse of the Morandi Bridge in Genoa, Italy, a section of bridge deck for the new structure was lifted into place, marking the first section to be installed.
According to The Local Italy, the section of bridge was lifted in the air by cranes, and was set across two concrete piles. When the structure is completed, 18 piles will support architect Renzo Piano’s structural vision of the new bridge.
Morandi Bridge Collapse
Late in the morning on Aug. 14, 2018, lightning struck the Morandi Bridge. At the time, 35-mile-per-hour winds were recorded with a thunderstorm moving through the area. A 200-meter (656-foot) section of the prestressed concrete span collapsed, creating a gulf between two sections of the bridge.
The cable-stayed concrete bridge, also known as the Polcevera Viaduct, completed in 1968, was designed by Italian civil engineer Riccardo Morandi. According to the website Retrofutur, the bridge is characterized, as are other Morandi structures, by thin prestressed concrete girders and relatively few stays. Three A-shaped concrete pylons held four prestressed stays apiece. The website has chronicled numerous projects over the years to reinforce the structure, including steel sheaths over the concrete pylons.
'Special day': First part of Genoa's new Renzo Piano bridge goes up https://t.co/C7CBaDi6w9— The Local Italy (@TheLocalItaly) October 1, 2019
While experts believe that structural weakness contributed to the collapse, previous warnings about the condition of the bridge were issued years before disaster struck. For example, in 2012, the leader of Genoa's business federation noted that the bridge could collapse within 10 years. In 2011, a report from Autostrade per l'Italia, the operator of the A10 highway that ran over the bridge, warned of intense decay.
Morandi penned his warning partially due to the perplexity of the degradation problem—the amount of corrosion that the bridge exhibited even early on wasn't seen on similar structures in different environmental circumstances. At the end of last August, Piano offered to help design a replacement structure signifying rebirth and redemption for the affected area.
In late November, testing of bridge debris began, which would help determine what caused the collapse. Demolition began in December. In June, the bridge’s towers were demolished.
The new structure will have a 3,600-foot-long main steel deck running across 20 spans, supported by 19 piers placed at 164-foot increments. It is slated to be open for traffic in April 2020.
Bridge Deck Progress
The section of bridge deck put into place earlier this month was 26 meters wide and 550 tons.
The new bridge will be equipped with a dehumidification system to help prevent salt condensation and corrosion, as well as photovoltaic panels.
“The tragedy stays with you, the victims stay with you, the displaced stay with you,” Piano said. “More than solace, it is moment of redemption.”
Nicola Meistro, CEO of Pergenova, noted that the bridge will have lateral robots to help with basic maintenance, including cleaning, along with cameras to help with visual inspection.
Salini Impregilo’s Pietro Salini also noted that the level of innovation and collaboration going into the project should be a model for the rest of the country.
“We have 36 billion euros in works blocked in Italy—this means having jobs, development, growth of young people blocked as well,” said Salini. “Yet, this work shows that infrastructures can be built in Italy. And that they can be done quickly and transparently, while maintaining a very high quality standard.”
As for the legal case surrounding the disaster, 71 people were accused, ranging from managers to civil servants, involving more than 100 lawyers, 120 experts and 75 witnesses.