ABSTRACT
This study investigates the earthquake-induced peak and residual tilts of the foundation of nine Italian monumental towers founded on soft soil, where a site-specific geotechnical characterization was available, and the fundamental period of the tower was measured through on site surveys. The correlation between the foundation rotation and the spectral acceleration calibrated by de Silva (2020) was exploited to properly combine the expected foundation rotation and the hazard curve at each site. The result is the so-called ‘demand hazard curve’, which allows to individuate the foundation rotation associated to different limit states for a preliminary and expeditious large-scale estimation of the most vulnerable cases. Moreover, the residual rotation expected to occur for the belfry of San Benedetto Church in Ferrara resulted very close to the increase of the tower tilt measured after the 2012 Emilia earthquake.
