Tower of Pisa
Construction of the tower occurred in three stages over 199 years.
The tower began to sink after construction had progressed to the second floor in 1178. This was due to a mere three-meter foundation, set in weak, unstable subsoil, a design that was flawed from the beginning. Construction was subsequently halted for almost a century, as the Republic of Pisa was almost continuously engaged in battles with Genoa, Lucca, and Florence. This allowed time for the underlying soil to settle. Otherwise, the tower would almost certainly have toppled.The seventh floor was completed in 1319. The bell-chamber was finally added in 1372. It was built by Tommaso di Andrea Pisano, who succeeded in harmonizing the Gothic elements of the belfry with the Romanesque style of the tower. There are seven bells, one for each note of the musical major scale. The largest one was installed in 1655.
At least four strong earthquakes hit the region since 1280, but the apparently vulnerable Tower survived. The reason was not understood until a research group of 16 engineers investigated. The researchers concluded that the Tower was able to withstand the tremors because of dynamic soil-structure interaction (DSSI): the height and stiffness of the Tower, together with the softness of the foundation soil, influences the vibrational characteristics of the structure in such a way that the Tower does not resonate with earthquake ground motion. The same soft soil that caused the leaning and brought the Tower to the verge of collapse helped it survive.
Properties of the tower
The original height of the tower of pisa is 60 m but because it is crooked the actual height is 58.67.
The tower during the second world war .
The tower during the war served as observation to the Germans.
The Americans wanted to bomb the tower, but Eventually they didn’t.
Guinness World Records
Two German churches have challenged the tower’s status as the world’s most lop-sided building: the 15th-century square Leaning Tower of Suurhusen and the 14th-century bell tower in the town of Bad Frankenhausen. Guinness World Records measured the Pisa and Suurhusen towers, finding the former’s tilt to be 3.97 degrees. In June 2010, Guinness World Records certified the Capital Gate building in Abu Dhabi, UAE as the “World’s Furthest Leaning Man-made Tower” it has an 18-degree slope, almost five times more than the Pisa Tower, but was deliberately engineered to slant.
To sum up, the tower of pisa is a very special place
with a lot of history. we recommend you to
come and visit.