The Leaning Tower of Pisa is in danger of collapsing.

Scientists say that the Leaning Tower of Pisa is very likely to collapse, even though it has defied time after 840 years. Although the tilt of the tower is quite large, it is still considered one of the favorite structures and attracts many tourists to the city of Pisa.

It started leaning when it was built in 1173. The builders only managed to build up to the third floor of the planned eight floors because they discovered that the ground was too sandy, muddy, and clay-based to support the tower. At this point, the tower was leaning to the south. To counteract this tilt, the designers tried to build higher columns and domes on the north side. Later, due to political instability, they had to temporarily stop building the fourth floor.



Leaning Tower of Pisa continues to sink

For nearly 100 years, the tower remained unfinished. The ground beneath the foundations continued to sink. By 1272, construction was resumed, but the tilt to the south continued as it does today. Engineers continued to attempt to correct the tilt, but with little success. Unfortunately, in 1278, the project was again halted after only seven floors had been completed.

Sadly, the building continued to sink to an alarming rate. The tilt became most apparent in the early 14th century, but this did not stop the authorities from continuing construction. Eventually, the building was completed. They tried to keep the tower balanced by placing the bell tower on the 8th floor, which leaned more towards the north.

Italian physicist Galileo Galilei once conducted an experiment on falling objects on the Leaning Tower of Pisa. The time when this scientist conducted the experiment was also the time when scientists believed that the tower was leaning about 3⁰. However, it was not until 1911 that actual measurements of the tilt of the Tower of Pisa were made. According to these results, the top of the tower tilted by 1.2mm every year.

In 1935, engineers expressed concern that the water level under the foundation was too high, which would weaken the foundation and accelerate the tilt of the Tower of Pisa. To prevent this, they decided to drill a network of holes under the base of the tower and fill them with cement.

However, this only made matters worse. The tower leaned even more than before. The government and authorities also set up teams of conservation engineers, who studied and proposed solutions to stabilize the structure. However, none of the solutions were effective and the tower continued to lean over time. By that time, the Pisa Tower was leaning 5.5⁰. Many people expressed deep concern about the existence of this structure when in 1989, a structure with a similar structure to the Leaning Tower of Pisa - the Pavia Bell Tower in Northern Italy suddenly collapsed.

After the collapse of the Pavia Bell Tower, the authorities decided to close the Pisa Tower for maintenance. A year later, many experts were invited to find effective measures to stop the leaning of the Pisa Tower.

John Burland, a soil scientist at Imperial College London, suggested that reducing the amount of soil on the northern base of the tower might allow the tower to return to vertical. To test this hypothesis, he and his colleagues designed a computer simulation to see if the plan could be implemented. After analyzing the data, they agreed that the plan was feasible.

Thanks to this plan, by 2011, the tilt of the tower had decreased by 44 cm, enough for the authorities to reopen the tower to the public. As of May 2008, the sensors had not detected any further movement of the tower.

In theory, the efforts of John Burland and his team could permanently stabilize the structure. But the real threat to the tower’s survival comes from its foundation, specifically the materials used to build its lower floors. If the foundation were to fail, the entire tower would collapse. Even a small earthquake could leave Pisa in ruins.

Despite the potential dangers the tower faces, scientists and conservationists hope that the structure will survive for at least another 200 years. By then, other measures may have to be taken, but with ever-evolving technology, most people hope that in 800 years the tower will still be standing as it is now.

According to zing.vn - vp