By Elton Gomes
The Leaning Tower of Pisa is leaning a little less than it used to. The Italian monument, famous for its tilt, has been improving its posture since 2001, and it has straightened nearly 1.5 inches since then.
According to the tower’s surveillance group (the tower is under constant monitoring by a group of scientists), efforts to reduce the tower’s lean are paying off.
“It’s still straightening,” said engineer Roberto Cela, while gazing at the Leaning Tower of Pisa. “And many years will have to pass before it stops,” as per an AFP report.
Nunziante Squeglia, a professor of geotechnics at the University of Pisa, who works with the surveillance team, added: “What counts the most is the stability of the bell tower, which is better than expected,” as per a report in the BBC.
Why does the tower lean?
According to Phys.org, the Tower of Pisa began to lean almost right from the start. The monument has been leaning for nearly 850 years now – ever since the masons began construction work back in 1173.
The reason for this unexpected twist of events was attributed to the soft ground on the tower’s south side, which caused the monument to lean in that particular direction.
“When they were building it, there were attempts to straighten it (by adding stone on one side), so it has a slight banana shape,” said Roberto Cela, who is also the technical director of the Opera della Primaziale Pisana—which is the organization that has been set up to supervise the construction works of all the monuments in the Piazza dei Miracoli.
Since the tower’s slanting tendency would have eventually resulted in collapse, engineers undertook a restoration project that helped in reducing the monument’s tily. The project lasted for eight years, which was why the tower was closed to visitors.
Why was it closed previously?
In January 1990, The Leaning Tower of Pisa was closed for repairs, because it was leaning too much.
“It took some 200 years to complete the Tower, but there were only about 20 years of actual work. Talk about a nightmare construction project!” Alicia Ault wrote for Smithsonian.
As a result of all this jostling, the tower leaned southward. Over the centuries, despite the efforts of many, it began to lean farther and farther, leading to the closure.
The tower didn’t reopen for 11 years, and even then, it was still slowly tilting.
How have engineers reduced the tilt?
The Tower of Pisa measures a little over 183 feet on its low side and almost 186 feet on its high side. The monument has a base diameter of 50.5 feet and weighs 16,000 tons. Engineers worked hard and had to be very careful while reducing the tilt.
“We installed a number of tubes underground, on the side that the tower leans away from. We removed soil by drilling very carefully. Thanks to this system, we recovered half a degree of lean,” Roberto Cela told Inquisitr.
The laborious restoration work paid off and the Leaning Tower of Pisa began straightening its posture by 17.5 inches in the last 25 years.
Although the tower has been officially re-opened to the public for 17 years, engineers are constantly monitoring its movements, and are taking precise measurements on an hourly basis. This has led to an improved understanding of how the Leaning Tower of Pisa began to lean a little bit less over the years.
“The tower tends to deform and reduce its lean in the summer, when it’s hot, because the tower leans to the south. So, its southern side is warmed and the stone expands. And by expanding, the tower straightens,” said Nunziante Squeglia, a professor of engineering at the University of Pisa, who works with the Surveillance Group, as per the Inquisitr report.
It has been reported that the monument will continue to straighten and it will keep doing so for many years to come, notes Cela. However, the engineer notes that the tower will not likely lose its charm: the Leaning Tower of Pisa “will never be completely straight.”
Elton Gomes is a staff writer at Qrius
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