Stabilisation of leaning structures: the Tower of Pisa case

The problem of leaning structures or buildings has many examples well known to engineers throughout the world. The tilting of tall buildings on footing foundations is frequently due to consolidation of compressible layers underneath, and is triggered by small geological details, by asymmetry, or by the construction of another structure in close vicinity to the building.

Very often the tilting effect tends to increase with time, owing to unfavourable concentration of stresses under the footings having larger settlements.

The superstructure may eventually collapse, under the action of gravity, owing to increasing secondary stresses induced by the tilted position.

In order...