Methods to know and preserve a heritage of the Italian historical theatres: the wooden stage

The work treats the refurbishment of a critical part of an historical theatre: the wooden stage. An opera house is characterized by the consistent use of perishable materials, such as the wooden floor, which is at the same time structural and acoustic element. On one hand the theatre geome- try and materials are the characteristic heritage of each theatres, on the other hand the utilization of theaters changes over time and therefore modifications are unavoidable. An Italian opera house has been used as a case study: the Alighieri theatre in Ravenna, designed by Tomaso Meduna and his brother (the former architect of La Fenice theatre in Venice). In 2015 the theatre wooden stage was replaced and the authors of this work were asked to study the influence of the wood ageing. A sample of the stage wood has been analyzed using vibro–acoustic techniques in laboratory and the stage has been qualified using musical instruments (cellos, double basses) and measurements. Finally, a model has been proposed in order to quantify the stage radiation.