The Behaviour of the Leaning Tower of Pisa in the Period 1993–1995

This paper deals with the analysis of the results obtained from three years of geodetic controls of the Leaning Tower of Pisa; during the last three years, 1993–1995, an International Multidisciplinary Commission, appointed by the Italian Government, has planned important works in order to stabilise the Tower. The studies presented in this paper try to understand the Tower behaviour and the deformations of its foundations due to a lead counterweight placed on the North external side of the Tower base, in order to decrease the Tower leaning towards South.Finally three methods to evaluate the Tower tilt in the North-South direction are described and compared. The deformation axes of the graphics here presented are not scaled and only few deformation data shown. This is because the results of the control are still under the study of the International Commission and for this reason, at the moment, cannot be published.