Why Does the Leaning Tower of Pisa Tilt?

Structural problems of inclination of Pisa tower of Italy

The exceptional inclination of the Tower generates a dangerous concentration of vertical compression forces in the lower masonry. The situation is particularly un-favorable in the 1st arcade, where:

• The door to the loggia and the passage to the helical staircase reduces the resistance of the region;
• The interruption of the marble facing (which continues around the opening) induces stress concentrations in the weak masonry filling underneath;
• Numerous scaffolding holes reduce the resistance of the region;
• Radial tension has already cracked the steps and the ceiling of the spiral staircase.
• Restoration of the masonry and of the connections between wall facings and infill by way of the injection of a specially formulated grout composed of a special cement.
• Radial pre-compression of the wall with 16mm stainless steel bars, to ensure linkage between facings and filling.
• Concentration of vertical compression forces in the 1st loggia. and also it has been constructed on very softy soil having maximum concentration of sand.also it is just 6 feet above the sea level.

Remedies

How to reduce the rate of leaning of the leaning tower of Pisa?

Its inclination is inch / 20 years if it is going on same rate after 300 years it will become plane with ground because up to 300 years it may remain safe. Some efforts were made by different engineers in different period of time some of them are given below:

Temporary geo-technical intervention

This consists in the application of forces which diminish the capsizing action of the Tower's weight and inclination. The forces can be vertical (ingots of lead, anchorage) or horizontal stays.

Stays

This system provides a means of countering potential unforeseen occurrences during future interventions on the Tower.

Anchorage

Hypothesis for a medium term intervention intended to substitute the weights, reducing unsightliness of counter-weighting.