Why is it that the leaning tower of Pisa does not fall?

Question

Why is it that the leaning tower of Pisa does not fall?

Answer 1

because though its leaning, its center of gravity doesn't go out of its base...so it's in its best stable position still...but if it leans further due to soil, it may fall for its center of gravity may change and therefore go out of its base...

Answer 2

it actually reached its state of equilibrium..

Answer 3

Two reasons, sort of. One, they shored up the foundations rather extensively over the last several years to correct the soil subsidence problem it always had.

Two, its center of gravity is not outside the center of support, the condition that defines stability. Any increase in the angle of lean would raise the center of gravity, which is another way of saying the same thing.

Answer 4

Even though it leans the center of mass (center of gravity) is still above its base. If the tower leans far enough that its center of mass is outside its base it will fall.

Answer 5

In the 1990's, engineers removed soil from underneath the raised end, straightening the tower by 18 inches. In May 2008, they  removed more soil, announcing the Tower has stabilized and stopped moving for the first time in its history. They stated it would be stable for at least 200 years.

http://en.wikipedia.org/wiki/Leaning_Tow...

Answer 6

It doesn't lean that much and it's very well built.