Leaning Tower of Pisa — The Physics Behind Its Leaning Tower

Written by Fabio Lucas Carvalho

Published on 21/12/2024 at 00:11

Foto: Reprodução

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The Famous Lean of the Leaning Tower of Pisa Is Supported by an Equilibrium Between Gravitational Force, The Clay Soil of The Region and Engineering Interventions, Challenging The Laws of Physics for Centuries.

The Leaning Tower of Pisa, an unmistakable symbol of Italy, has maintained its unstable position for over 650 years. But its lean hasn’t always been the same. In the 1990s, for example, the tower reached its peak in drama, leaning at 5.5 degrees.

At that time, it was closed to the public due to the risk of collapse. This fear was heightened by the collapse of the Civic Tower of Pavia in 1989.

The disaster raised an unavoidable question: was it possible to save the Leaning Tower of Pisa from a similar fate?

ARTICLE CONTINUES BELOW

The Beginning of The Lean: A Soil Mistake

The construction of the tower began in the 12th century, but soon encountered problems due to the soft soil. The structure began to lean even before it was completed.

It took nearly 200 years to finalize the project, which faced a long pause during a tumultuous period in the Republic of Pisa. Ironically, this pause allowed the soil to settle, preventing the tower from completely collapsing.

By the end of the 13th century, the solution found for the problem was ingenious and peculiar: to build the upper floors with a curved shape to compensate for the lean. This adjustment gave the tower its unique appearance, which today delights millions of tourists annually.

Frustrated Correction Attempts

Over the centuries, engineers have tried everything to straighten the tower, but the results were disastrous. In 1934, Benito Mussolini ordered the injection of concrete into the foundation, believing this would solve the problem.

The effect was the opposite: the lean increased even further. Only in the second half of the 20th century, with advances in technology, was it possible to study the soil and the structure precisely.

Finally, an effective solution was implemented in the 1990s. Part of the soil under the higher side of the tower was removed with an inclined drill, which reduced the lean to about four degrees — an angle similar to what was recorded two centuries earlier.

After the stabilization process, experts assured that the tower would remain safe for at least another 200 years.

A Structural Enigma

The question that intrigues many is: how has the Leaning Tower of Pisa never been toppled by an earthquake? The answer lies precisely in the soil that caused its lean.

Studies show that the soft ground acts as a cushion against seismic vibrations. In short, the same element that threatens the stability of the tower protects it from earthquakes, an irony that reinforces its worldwide fame.

What started as an apparent engineering disaster has turned into one of Italy’s greatest prides. The Leaning Tower of Pisa, with its history of challenges and triumphs, is now a living example of how human ingenuity and natural peculiarities can create something truly unique.

Technical Data of The Leaning Tower of Pisa

Feature	Detail
Official Name	Leaning Tower of Pisa (Torre Pendente di Pisa)
Location	Pisa, Italy
Start Date of Construction	August 9, 1173
Completion Date	1372
Current Age	851 years since the start of construction; 652 years since completion
Height	55.86 meters on the highest side; 56.67 meters on the lowest side
Current Lean	Approximately 4 degrees (after stabilization corrections)
Base Diameter	15.484 meters
Total Weight	Approximately 14,500 tons
Main Material	White Marble
Number of Stories	8 (including the base)
Original Function	Bell Tower of the Cathedral of Pisa (Duomo di Pisa)
Architect	Bonanno Pisano (attributed, though not historically confirmed)
Architectural Style	Romanesque
Correction of Lean	Stabilization projects carried out between 1990 and 2001
World Heritage	Declared by UNESCO in 1987

Leaning Tower of Pisa — The Physics Behind Its Leaning Tower

The Famous Lean of the Leaning Tower of Pisa Is Supported by an Equilibrium Between Gravitational Force, The Clay Soil of The Region and Engineering Interventions, Challenging The Laws of Physics for Centuries.

The Beginning of The Lean: A Soil Mistake

Frustrated Correction Attempts

A Structural Enigma

Technical Data of The Leaning Tower of Pisa

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Leaning Tower of Pisa — The Physics Behind Its Leaning Tower

The Famous Lean of the Leaning Tower of Pisa Is Supported by an Equilibrium Between Gravitational Force, The Clay Soil of The Region and Engineering Interventions, Challenging The Laws of Physics for Centuries.

The Beginning of The Lean: A Soil Mistake

Frustrated Correction Attempts

A Structural Enigma

Technical Data of The Leaning Tower of Pisa

The Soviet Union spent 22 years drilling into the Earth’s crust and reached a depth of 12,262 meters — they found water where it was thought impossible, hydrogen bubbling from the rock, granite that is 2.7 billion years old, and temperatures of 180 degrees that melted the drill bits.

Egypt wants to draw 10 million cubic meters of water from the Nile per day into the desert, irrigate a new agricultural frontier, and build a city where there is currently only sand.

Ethiopia has banned gasoline and diesel cars, placed over a hundred silent electric buses on the streets of Addis Ababa, and now aims for half a million electric vehicles by 2030, all powered by Africa’s largest dam and a courage that few countries have shown.

Norway is drilling 27 kilometers of rock 392 meters below the bottom of a fjord to build the world’s largest and deepest underwater road tunnel — when completed, a 21-hour journey will be reduced to 10.

An astronaut spent 340 days in space while his twin brother stayed on Earth, and NASA found a “rejuvenating” effect, genes, microbiome, cognition, and immune system that revealed the biological cost of living outside the planet.

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