Updated: Jun 15
Do you know the reason for how the leaning tower of Pisa is standing strong? Are all the interventions in education sector this strong?
It dates back to 1173 (12th century) when the Republic of Pisa set to increase the sizes of the buildings at the central square to make it a magnificent landmark. Originally the tower was built for a shorter structure for which the engineers thought that just a 3 meter foundation would suffice. Unfortunately by the time they constructed the fourth floor, they saw that the southern side of the tower was already underground and there was a halt because of the war in Pisa for over a century. When the construction was resumed on 1272, they tried to compensate by adding more floors to the southern side and again because of more masonry the tower got more tilted by the time they reached seventh floor. There were several attempts to prevent it from tilting further:
In1838, a walkway was dug near the base around the tower to examine but this only worsened and it got tilted further because of removing the supporting sand.
In 1935 mortar was injected to strengthen the base which again tilted it further.
and many more failed attempts. Finally after 6 centuries, further tilt was fixed by doing the following:
Post world war the researchers realised that the soil was marshy (Pisa got its name for the marshy land). And the structure didn't fall initially because of the century long gap during war when the soil got settled.
The trajectory of the tower, centre of gravity and soil stability was calculated and 38 cubic meters of soil was removed from north. It was counter balanced with 600 tonnes of lead ingots and was anchored to the base with steel cables.
It is estimated that the structure will stand strong for atleast 300 years.