Seismic and Vibration Protection of the Statue "Pieta' Rondanini" By Michelangelo

Abstract eng:
The paper describes the innovative system that protects the statue "Pietà Rondanini" by Michelangelo Buonarroti from both earthquake and traffic-induced vibrations. The marble statue was the last incomplete job by Michelangelo Buonarroti (14751564), housed in the Sforza Castle in Milan. This statue, as many artifacts in our museums, is facing problems related to traffic induced vibrations in cities that are becoming more and more crowded. Italy is a well known seismic-prone country, so this adds the need to protect these artifacts from earthquakes. The relocation of the statue to a new room of the Castle, would have exposed the masterpice to an important vibration dose produced by the underground trains running underneath. Therefore it was decided to develop a base able to protect the statue from traffic vibrations and earthquake, avoiding any possible marble damage. The solution consisted in a special base, equipped with both a seismic isolation device (guides with recirculating steel balls which converts a mechanical linear motion into a rolling motion) and rubber bearings, to reduce the effects of traffic induced vibrations. A steel cylinder has been mounted on the top plate of the isolation base, which hosts an internal safety retaining system to preserve the statue from possible rocking. This system allows the oscillation of the statue when the horizontal actions are above a predetermined threshold. In the case of displacements greater than those anticipated in the design, a stopping system equipped with fuse dissipation devices ensures a base movement limit, due to a progressive energy dissipation. These systems have produced a redundant protection against seismic action and any other exceptional events, in order to ensure a safety level fit for the high "cultural" value of the statue within the Italian and the world heritage. The base isolation system was tested on a shaking table up to twice the code seismic action to verify the protection against the earthquake. The capability to filter lower vibrations produced by traffic was also tested. Shaking table tests were carried out on a copy of the real statue made of marble as the original. Tests were performed on a multi axes shaking table and the tests were: sweep sine tests, tri-axial seismic tests, uniaxial vibration tests, manual impacts. The tests show the effectivness of the designed innovative system that protects the statue "Pietà Rondanini" by Michelangelo Buonarroti from both earthquake and traffic-induced vibrations. The system implements a solution that shifts the natural frequencies of the structure in frequency ranges where the excitation due to underground traffic and earthquakes is the lowest.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket