PREDICTIONS ON THE SEISMIC RESPONSE OF MONUMENTAL TOWERS ON SOFT SOIL

After the damages to the cultural heritage caused by the most recent earthquakes, the protection of ancient buildings is an urgent and relevant theme in Europe, especially in the Mediterranean countries, characterized by high seismic hazard. The fine tuning of the seismic protection requires analyses on refined models in order to catch the dynamic behaviour of the soil–foundation– structure system in a lifelike way. Neglecting soil structure interaction effects, in fact, may be conservative or not, depending on the structural pattern and the nature of the subsoil. Focusing on the historical towers, the most symbolic building among monuments, a method is here proposed for preliminary predictions on the variation of natural period and damping ratio due to the dynamic interaction between soil and structure. The simplified approach is then applied to three cases of monumental towers on soft soil, located in three European cities, characterized by high seismic hazard.