The Leaning Tower of Pisa, in Italy, is the bell tower of Pisa Cathedral and has a tilt of 3.97 degrees. The tower began to lean at the start of its construction.
The Leaning Tower of Pisa was designed to be completely vertical, but it began to lean shortly after construction began, because The ground on which it stands is unstable., consists of sand and clay.
In addition, the The foundations of this structure are only 3 meters deep, which were not strong enough for a structure 55 meters tall. All of this caused the tower to lean first toward the north and then toward the south.
The Leaning Tower of Pisa was closed to the public in 1990 because the structure was tilting at a rate of up to 3 millimeters per year.
The Leaning Tower of Pisa: Monitoring Its Behavior
A few years ago, a team of experts managed to to stop the tower from leaning, using a complex system of reinforcement and ground leveling. In addition, a monitoring device was installed that allows for millimeter-precise observation of the structure's behavior. The tower has now been reopened to the public.
Thanks to this work, the slope’s angle was also corrected by half a degree, using 38 cubic meters of soil.
Construction of this tower, which is about 14,700 metric tons, began in August 1173, and their Construction took nearly 200 years and was divided into three phases: a first phase, during which the first three stories were built (1173–1178), a second phase, during which construction continued up to the seventh floor (1272–1278); and the final phase, during which construction was completed (1360–1370).
Currently, the Leaning Tower of Pisa It has become one of the most visited places on the entire planet.
