Genoa San Giorgio Bridge Genoa, Italy

GENOA SAN GIORGIO BRIDGE

The highly-anticipated motorway bridge in Genoa finally opened to regular traffic, nearly two years after the collapse of its predecessor, Ponte Morandi.

The Viadotto Genova-San Giorgio, also known as Genoa San Giorgio Bridge, is now opened to regular traffic.

Designed by renowned Italian architect Renzo Piano, the 1,100-metre-long concrete and steel viaduct carries four lanes of the A10 motorway across the Polcevera River in the northwestern city of Genoa. The Genoa San Giorgio Bridge is the replacement for its predecessor, Ponte Morandi, which collapsed during a heavy rainstorm on 14 August 2018. The tragedy, one of the worst infrastructural failures in modern Italian history, claimed 43 lives, injured more than a dozen, and left hundreds homeless.

The design and build of the new US$220 million replacement bridge over the Polcevera River and the area of Val Polcevera was completed in less than two years following round-the-clock construction.

“Its rapid reconstruction aims to become a model for the renovation and adaptation of Italian infrastructure with a high social, economic and strategic significance,” said Piano’s studio Renzo Piano Building Workshop.

Described by the studio as an “urban bridge”, the bridge’s deck is supported by 18 slender reinforced concrete piers spaced 50 metres apart except in the central section where they are separated by 100 metres.

Each of the piers has an elliptical section designed to allow the light to “slip” on the surface and help mitigate the impact on the neighbourhood below. The piers support a steel and concrete deck that is isolated by a system of support devices that are designed to protect the structure from seismic activity.

According to Piano’s studio, the underside of the deck is curved to be reminiscent of the form of a ship. “From an architectural point of view, the form described by the deck, which

A rendering of the Saint George Bridge in Genoa, Italy.

(Source: Renzo Piano Building Workshop)

(Source: Shunji Ishida)

(Source: italymagazine.com)

recalls the hull of a ship, is of great importance,” said the studio.

The studio also added: “The gradual reduction of the section towards the ends of the bridge attenuates the visual impact of the new infrastructure. In addition, the use of a light colour for the coating of the steel elements makes the bridge bright, harmonising its presence in the landscape.”

Along the sides of the bridge deck are a series of metal fins that extend from the bridge’s steel structure along with rows of photovoltaic panels that will power its lighting and a 2.5-metrehigh protective glass barrier.

“The transparency of the glass and, consequently, the extreme visual permeability that derives from it, makes it possible to observe the surrounding landscape by crossing the new bridge, as well as lightening its presence in the valley for those who will live it from the city,” said the studio.

Described as an “intelligent instrument” by the studio the bridge will be continuously monitored using a system of internal sensors including accelerometers, extensometers, velocimeters, inclinometers and detectors for joint expansion. These sensors will be supplemented by robots, which runs along the rails on the bridge’s edge to monitor the superstructure externally and will also clean the photovoltaic panels.

The Genoa San Giorgio Bridge replaces the Ponte Morandi, a cable-stayed bridge that was erected in 1967. Nicknamed in tribute to its famed structural engineer, Riccardo Morandi, the busy viaduct served as both a crucial transportation link in the Liguria region and an enduring architectural landmark for Genoa, Italy’s sixth most populous city. Considered a marvel of modern engineering, the bridge was a soaring point of pride, literally, for Genoa. The Ponte Morandi was fully demolished in June 2019. As part of the plan to rejuvenate of the area under the collapsed bridge, Milan-based architect and urban planner Stefano Boeri has designed elevated walkway as part of the Polcevera Park and The Red Circle masterplan.