THE DYNAMIC PROPERTIES OF THE ASINELLI TOWER IN BOLOGNA

The Asinelli Tower, built at the end of the 12th century, is one the main symbol of the town of Bologna and a valuable historical heritage of the Medieval age of the entire Italy. For its struc-tural configuration, the tower appears prone to seismic damages and, therefore, an assessment of its dynamic properties is of primary importance in order to predict the tower seismic re-sponse. In the present paper, based on the results of limited material tests, the mechanical and dynamic properties of the tower are analysed through the development of models of increasing complexity. First, models for the evaluation of the main mechanical properties of the masonry (such as the elastic modulus, the Poisson's coefficient, the compressive and shear strengths) are compared in order to validate the experimental results. Then, different structural models of the tower (from simple continuum analytical models to more complex finite element models) are developed. The analytical and numerical results obtained from the different models are finally compared to some recent experimental measurements of the free vibration response of the tow-er conducted by the INGV (the italian National Institute of Geophysics and Volcanology). The preliminary results indicate that the experimental frequencies are in good agreement with the values obtained from the models.