Structure and History of the Leaning Tower of Pisa

The Leaning Tower of Pisa began leaning in 1178 due to inadequate foundations. Construction paused for nearly 100 years due to wars, allowing the ground to settle. Resumed in 1272, the tower was completed in 1372, leaning at 4 degrees. Over 600 years, the lean increased, prompting stabilization efforts in 1964. Engineers used lead weights and soil extraction to reduce the lean, ensuring stability for another 200 years.

What was the primary reason the Leaning Tower of Pisa did not collapse during its initial construction phase?

• The builders corrected the lean immediately.

• The tower was built on solid ground.

• The foundation was reinforced immediately.

• Construction was paused due to wars.

How did the builders compensate for the lean when the belfry was added in 1372?

• They added extra weight to the base.

• They used a counterweight system.

• They reinforced the foundation with concrete.

• They adjusted the construction to balance the lean.

What was the angle of the tower's lean when it was completed in 1372?

• 3 degrees

• 2 degrees

• 4 degrees

• 5 degrees

What temporary measure was taken in 1964 to prevent the tower from falling?

• The tower was straightened using jacks.

• 900 tonnes of lead was added to the base.

• A steel frame was built around the tower.

• The foundation was completely rebuilt.

What modern technique was used to reduce the tower's lean by half a degree?

• Using hydraulic jacks to lift the tower

• Extracting soil from beneath the high side

• Rebuilding the foundation

• Adding more lead weights