Protecting Pietà Rondanini against Environmental Vibrations with Structural Restoration Works

Michelangelo Buonarroti devoted the last years of his life to work on Pietà Rondanini. The statue reached Milano in the ‘50s and it became one of the most important pieces of the Castello Sforzesco collections. In view of Expo 2015, Ospedale Spagnolo was chosen as the new exposition space for the artwork. Subway lines under the new space was recognized as source of vibrations, not present to the same extent in the previous location. Since there is no consolidated knowledge about the effects of low and continuous vibrations on ancient marble, this type of excitation is discussed in this work, together with the peak vibration levels usually considered in scientific literature. In the case study of this work a conservative approach has been applied, reducing as much as possible both peak and mean excitation levels. This goal was achieved in the ambit of the restoration works with a proper selection of construction materials, a proper structural design and the selection of the best position of the statue relying on local vibration characteristics. The Pietà Rondanini project has been an important occasion to deal with both general problem of environmental vibrations in museum rooms and one possible way to solve it.