The Genoa Bridge Collapse 2018 (Documentary)

The Genoa Bridge Collapse 2018 (Documentary)
The in-depth story of the Genoa Bridge Collapse 2018. The Morandi Bridge is bustling with traffic. It carries the A10 motorway, the transport artery of the northern Italian riviera that also links Italy with France. Thousands of passengers are crossing the bridge..

Ferragosto – the day when Italy stops. On this public holiday, Italians take
a rest from their work and everyday routine. It’s August 14, 2018, the day before the holiday,
and the weather is all but sunny in Genoa. A torrential rainstorm hits the city.
But locals don’t let the superstorm stop them from heading toward the beautiful holiday
centres along the coast of the Ligurian Sea. The Morandi Bridge is bustling with traffic.
It carries the A10 motorway, the transport artery of the northern Italian riviera
that also links Italy with France. Thousands of passengers are crossing the bridge
One of them is truck driver Luigi Fiorillo in his blue and green Volvo FM 300. It’s raining cats and
dogs, but Fiorillo has a delivery to make. A bolt of lightning strikes one of the bridge towers as
he approaches it. Seconds later, through the heavy mist of rain, Fiorillo notices a vehicle
disappearing through the asphalt. Suddenly, he realizes the bridge is collapsing in front of him.
He pushes the brakes as hard as he can and nails his truck just a few yards from the abyss.
Luigi stands on the verge of death but manages to run away from his vehicle.
He runs and doesn’t look back. Not until he reaches solid ground. While the rain pours
on him, he sees the bridge and is overcome with disbelief, realizing what a disaster he survived.
The Morandi Bridge was one of Genoa’s landmarks. Popularly known as the “Brooklyn Bridge,”
the multi-span cable-stayed bridge vaguely resembled the famous construction in New York.
It had a length of 3,878 feet (1,182m), crossing the Polcevera River valley at the height of
148 feet (45m) {at road level}. The bridge was supported by reinforced concrete piers and three
inverted-V-shaped 300-feet-tall pylons. Each tower supported four cable-stays stretching to both
sides of the bridge’s deck. The Polcevera Viaduct, as it was called officially, was built in 1960,
the golden age of the Italian economy, to bypass the traffic-congested downtown Genoa.
Better connectivity became necessary as the country’s trade and living standards increased.
Italians began building motorways. Genoa became a crossroads connecting the Ligurian Riviera
with southern France and the northern Italian cities of Turin and Milan.
The bridge, which was actually a viaduct, was designed by the famous Italian engineer Riccardo
Morandi, after whom it was named. It took four years to build, from 1963 to 1967, when Italian
President Giuseppe Saragat inaugurated it. The Morandi Bridge was yet another of the
engineer’s successful accomplishments after he became famous for building the “General Rafael
Urdaneta Bridge” in Venezuela. Despite being much longer, the Venezuelan bridge was similar in its
basic design. They were both cable-stayed bridges built using reinforced and prestressed concrete.
Riccardo Morandi was the pioneer of using prestressed concrete in engineering.
As the word itself says, this type of concrete is being stressed during production. Namely,
high-strength “tendons” within the concrete volume are being tensioned before the
concrete solidifies. Once the concrete becomes solid, the tendons are released,
thus applying compressive stress to the concrete structure. In this manner, the stress of the
tendons counteracts the compression forces of the load applied to the concrete structure.
Compared to reinforced concrete structures, prestressed concrete
is much stronger. Engineers use it to build strong constructions with less structural thickness and
fewer supporting elements. It goes without saying that this technique saves money. For this reason,
the prestressed concrete greatly benefited the rising Italian post-war economy.
While the industry lacked steel to build with, the country was abundant in concrete-making materials.
Morandi became the construction guru, and his technique became a symbol of Italian architecture,
applied by engineers across the country. Thousands of viaducts,
bridges, tunnels and other constructions were built using prestressed concrete.
One of them was the Morandi Bridge in Genoa. The deck and most of the structure was made of
reinforced concrete. However, prestressed concrete was used for the cable-stays, which was quite
unusual at the time. Most suspended bridges had steel cable-stays, but the Morandi Bridge had them
housed inside the prestressed concrete box, thus reducing the use of steel in its construction.
It allowed the designer to achieve a distinctive slender design. Each cable-stay was capable of
carrying 33,000 pounds (15,000 kg) of weight, which allowed large spans between pylons.
Morandi was proud of the work he had done, as was the public. The press stated,
“The bridge’s concrete structure won’t need any maintenance, neither will its stayed cables,
which are protected from atmospheric agents by their concrete vest” d. Indeed,
the bridge would carry heavy loads over time. The traffic increased with each year,
reaching over 25 million transits annualy. The summer holiday brings tourists to
the Ligurian Riviera, which naturally increases traffic. On Tuesday, August 14,
2018, it was a busy day at the bridge, as expected. Nothing unusual, one might say.
Then, all of a sudden, at 11:36 am, the deck on both sides of the pylon number nine collapsed at
points where it connected the stays. Like a house of cards, it was followed by the deck in between,
the stays, and ultimately the entire tower fell. It all happened so quickly
that drivers crossing the bridge had no time to react. At the moment of the collapse,
a car traveling westwards flew into the air before the collapsing pylon took it down. A truck driving
in the opposite lane fell down as the deck under its wheels collapsed. Luigi Fiorillo’s
blue and green Volvo FM 300 stopped just a few feet before the edge of the collapsed bridge.
It later became the symbol of the disaster. Between 30 and 35 cars and three heavy vehicles
fell from the bridge. The drivers on both sides of the collapse halted their vehicles and began
to flee, fearing that the rest of the bridge would follow suit. In the end, only a part
650 feet (200 m) in length held by the ninth pylon cable stays collapsed. It fell on the
Polcevera riverbed, railway tracks, and some of the structures landed on warehouses belonging to a
power engineering company. Luckily, the facility was almost empty due to the upcoming holiday.
The collapse produced a thunderous sound, deceiving the nearby building’s residents
into believing an earthquake had occurred. But, to their surprise,
they saw that an entire section of the bridge was missing. A heap of concrete was all that was left.
The accident raised the alarm throughout the city. Medics and firefighters from all
hospitals and stations raced to the scene. There was little they could do, however,
as the chunks of the bridge were too heavy to be lifted without special machinery. To make
matters worse, heavy rain kept falling. The news of the disaster spread quickly.
Over 250 firefighters from across Italy gathered at the scene to help recover the
people trapped underneath the rubble. They had to use climbing equipment and sniffer
dogs to find survivors and locate victims. Rescue workers carefully searched for survivors
for two days, clearing the pile piece by piece. Although time was of the essence for those trapped
beneath tons of concrete, speeding up the clearing process would only have made matters worse.
After the collapse, large chunks of concrete created pockets in which people were trapped.
Sudden movements of these parts risked collapsing the pockets. When rescuers located the survivors,
they carefully removed layers of debris on top of them using heavy cranes.
More than 400 residents from the buildings underneath the bridge
were evacuated due to fears that other parts of the bridge might collapse.
The railway traffic was also suspended for the same reason.
The disaster was terrifying. The fact that sixteen people survived was deemed a miracle.
A driver whose car fell off the bridge escaped without a scratch.
Even though it toppled from the height of 148 feet (45m) along with tons of concrete, the car didn’t
smash, and the driver walked away unharmed. Unfortunately, 43 other people didn’t survive
the bridge collapse. Their bodies were recovered and taken to a hospital for identification.
Eighteen of them were buried in a state funeral on August 18.
Italy was shocked at the news that the Morandi Bridge had collapsed out of the blue.
The experts, however, weren’t as surprised. They knew the collapse was inevitable.
Morandi Bridge suffered from serious structural problems, one of which surfaced in the very first
year after its completion. It became clear that engineers miscalculated the creep of the concrete.
As a result, concrete undulated in all three dimensions, resulting in a bumpy
deck. The problem was finally fixed in the mid-1980s after a series of structural repairs.
Another problem was the aging of the bridge. During the construction, prestressed concrete
elements were exposed to compressive pressure of only ten megapascals, making them susceptible to
premature cracks. Generally, 32 megapascals are considered high-strength concrete and are used
to construct structural elements such as bridges. It allowed water to intrude and cause corrosion of
steel elements inside. Even Morandi was surprised at how fast his bridge was deteriorating.
In 1979, he compiled a detailed report on the condition of the bridge,
recommending the authorities remove all traces of rust on the exposure of the reinforcements,
fill the patches with epoxy resin, and cover everything with elastomer of very high chemical
resistance. This would then prevent further corrosion and deterioration of the structure.
Despite all the improvements and redesigns, the bridge continued to deteriorate at a fast pace.
In the 1990s, the condition of the cable-stays was alarming. About 30% of
the stays on pylon number eleven had corroded away, reducing the load per stay by half.
The company that maintained the bridge, Autostrade S.p.A, was forced to make serious improvements to
the structure. Stays at pylon eleven were reinforced using external steel cables.
On pylon number 10, stays were strengthened with steel sheathing at the top. However,
the ninth pylon had no reinforcements installed. As years passed, the bridge’s condition didn’t
improve and began causing concerns. In 2016, two years before the disaster, Antonio Brencich,
an expert in reinforced-concrete construction and professor at the University of Genoa,
pointed out what other experts had been claiming for years – the Morandi Bridge was “a failure of
engineering” and needed to be replaced. By that time, the cost of the improvements made
on the bridge surpassed the eventual cost of tearing it down and building a new one.
That same year, Senator Maurizio Rossi filed a question to the Ministry of Infrastructure
on the condition of the road network in Genoa. Senator Rossi claimed, “The bridge has been the
subject of a worrying failure of the joints which made it necessary to carry out an extraordinary
maintenance work without which there is a real risk of its closure” and asked if Morandi Bridge
should have been closed to heavy traffic. In October 2017, Professor Carmelo Gentile
of the prestigious Politecnico di Milano conducted specific measurements of the acoustic properties
of the bridge’s structure. In Professor Gentile’s report, significant anomalies were noted in the
stays of pylon nine. For that reason, he suggested installing a monitoring system in order to take
timely measures before something serious happened. But unfortunately, neither Autostrade management
nor the authorities paid attention to the report. In April 2018, the Autostrade company finally
decided to upgrade the bridge structure with an accent on nine and ten pylons. A tender was issued
for 21.4 million dollars (20.15 million euros). Work was scheduled to begin in autumn 2018,
roughly six months later, and last for five years. Before work began, Autostrade workers upgraded
safety by installing concrete Jersey barriers. The result was an increased load
on the already weakened bridge. On August 14, the bridge structure finally gave in.
According to the report by the commission formed by the Ministry of Infrastructure published in
September 2018, the cause of the collapse was not the breakage of stays but of other structural
elements like edge beams of buffer decks or caisson decks conditioned by advanced corrosion.
The commission also noted that the lack of care during the bridge’s
construction contributed to its collapse. In the end, the report blamed the Autostrade
management for “underestimating the unequivocal warning signal, minimizing or concealing the
seriousness of the situation to the Ministry of Infrastructure, and not adopting any precautionary
measures to protect users.” Clearly, the company in charge of maintaining the bridge
was aware of all the deficiencies but was reluctant to spend funds on repairing it.
Unfortunately, 43 lives had to be lost for those responsible to take action.
Italian Prime Minister Giuseppe Conte visited Genoa to inspect the disaster site personally.
During a cabinet meeting he held in the city, a decision was made to declare a state of emergency
for 12 months in Liguria and to release 5 million euros to help with immediate needs.
The government was about to regain control over the Autostrade company – which was
privatized – in charge of infrastructure. As for the bridge, the government decided
there would be no further improvements. It was to be demolished and replaced with a new bridge.
On June 28, 2019, the remaining pylons number ten and eleven were razed to the ground with a tonne
of explosives. Three days earlier, construction on a replacement bridge, Genoa-Saint George Bridge,
began. The inauguration of the new bridge over the Polcevera valley took place on August 3, 2020.
Ferragosto 2018 was indeed the day when the whole of Italy stopped, but to mourn the
compatriots who lost lives in an engineering disaster that could have been easily avoided.
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