Propping Up Pisa—Part Two

Abstract

This paper describes some of the engineering aspects of the work of the Italian Prime Minister's Commission for stabilizing the Leaning Tower of Pisa, and is presented in two parts. Part One (Volume 3, Number 2), presented a brief history of the construction and subsequent behaviour of the Tower as deduced from careful measurements made on the masonry courses. The deduced history of inclination of the Tower has been used to calibrate a sophisticated computer model of the Tower and underlying ground. Some surprising findings from recent studies of the motion of the Tower were presented. Part Two of the paper describes how the studies presented in Part One were used in developing the short-term stabilization measures that have been implemented by the Commission. Measurements made on the response of the Tower to these measures are presented. Finally, the work of the Commission in developing a permanent solution is summarized.