Genoa Bridge Aims for Summer Completion
Reported earlier this week, hundreds of construction workers in Genoa, Italy, are working around the clock to ensure that the city’s replacement of the Morandi Bridge is completed by the summer deadline.
“It is the building site that never sleeps,” Nicola Meistro, Operative Director for builder Salini Impregilo.
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.
Engineers working around the clock to complete Genoa bridge by summer https://t.co/eVP8UHWdm6— Andres Guzman (@ingandresguzman) February 12, 2020
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. By the end of 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.
The following month, Genoa Mayor Marco Bucci announced that three Italian firms—construction firm Salini Impregilo, state-run shipbuilder Fincantieri’s infrastructure subsidiary and the Italferr state railway subsidiary—would be handling the replacement of the Morandi Bridge in a joint venture called PERGENOVA. Later that month, demolition began on the 202-million-euro ($229 million) project, and in June 2019, the bridge’s towers were demolished.
Later in the fall, 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.
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.
What’s Happening Now
According to reports, work is now past the halfway mark regarding the completion of the new Morandi Bridge, as 16 of the 18 40-meter-high (131 feet) columns—which are partially sunk 50 meters into the ground—have been constructed and seven out of 19 deck sections have been laid.
“We are convinced that this can mark the beginning of a turning point for our sector, a turning point for the country,” Meistro said.
Salini Impregilo has been the entity building the reinforced concrete piers and will also be responsible for the paving of the road once the bridge has been completed. While the deck sections are being handled by Fincantieri at its plants in Valeggio sul Mincio, Castellammare di Stabia and Sestri Ponente.
Additionally, Reuters adds that some 70,000 cubic meters of concrete has been used in the construction of the viaduct, which extends roughly 1 kilometer across the valley.
Once completed, Salini reports that the bridge will encompass 67,000 cubic metres of concrete, will use solar panels to power lights on the infrastructure, in addition to incorporating sensors and other technologies to provide a constant monitoring of the structure. Robots are also expected to inspect the soundness of the bridge and intend to conduct regular maintenance to the newly constructed infrastructure.
“The bridge is set to be completed before summer 2020 so we are making every possible effort to meet this deadline,” site construction manager Stefano Mosconi said.