The Duomo of Milan: Some recent interventions on the main spire and on the tiburio vaults

The Duomo of Milan represents one of the most important and magnificent Cathedrals around the world. The construction started in the 14th century and continued until the 18th with the completion of the main spire and the statue of the Madonnina crowning it. This Cathedral is characterized by the use of Candoglia marble, with noteworthy mechanical properties, but sub-jected to physical degradation over time. For this reason, restoration works began from the 19th century and are still going ahead, involving in different periods the main structural and non-structural portions of this Cathedral. In this paper, some recent interventions on the main spire and on the Tiburio vaults supporting it are described. The design of these restoration works has been guided by a synergetic combination of different disciplines: geometrical survey, historical analysis and structural analysis based on simplified approaches as well as on more refined numerical models. This approach has been adopted to guarantee a successful interven-tion in due respect of the structural safety of the Duomo as well as of the preservation of the historic and architectural value of this Cathedral.