The Leaning Tower of Pisa is in good health And it will also be monitored from above
A check on the state of health 23 years after the last operation is in order, especially if the patient is a solid 850-year-old lady and the best-known symbol of Italy in the world. The Leaning Tower of Pisa is doing well – explains Nunziante Squeglia, professor of geotechnics at the University of Pisa – indeed, it is better than we expected. What happened in these 23 years? The well-known bell tower of Piazza dei Miracoli straightened, gaining a degree of upright position, about 4 centimeters since the international committee coordinated by Michele Jamiolkowski, which included Salvatore Settis, Carlo Viggiani and of which Squeglia was the operational arm, dug under the north side to avoid its collapse.
If we look at the data on the course of inclination over time – continues Squeglia – we discover that the bell tower has continued to straighten itself with a very slow and progressively slower motion. The intervention of the committee had reduced the overhang by about 40 centimetres, to which another 4 centimetres, approximately, were gradually added. Currently out of plumb by about 5 meters and with a collapse of more than 3, the tower is therefore struggling daily against the force of gravity, a struggle which, however, does not seem destined to end anytime soon: If it continued to straighten itself at this rate, it would straight in about 4 thousand years. I remember when the brilliant solution adopted for stabilization was severely criticized at the time of its construction – to conclude – the monitoring of the bell tower played an important role both in identifying the causes of the slope and in defining the countermeasures aimed at stabilizing the monument. Monitoring that will also have eyes from the sky thanks to an agreement reached between the Opera Primaziale and the Ministry of Culture. These are measures for controlling the inclination and for forecasting the future trend of the phenomenon, also in view of safeguarding against structural problems – comments Marica Mercalli, director general of Heritage Security at the Ministry of Culture – a series of new and different techniques such as ground-based radar interferometer and imaging techniques with very high resolution cameras. We are currently carrying out some installations that will allow this comparison to be made in real time. The memory of that 6 January 1990 – concludes Piefrancesco Pacini, president of the primatial Opera – the day in which the bell tower was closed, today appears distant for the past time and because now every day, hundreds of tourists climb the three hundred steps that lead from the base up to at the top of the belfry. this therefore the occasion, almost a year in advance, to begin the celebrations of the 850th anniversary of the laying of the first stone which took place on 9 August 1173.
December 1, 2022 | 09:22
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