Seismic Characterization of Historical Buildings in San Marino Republic From Ambient Vibration Monitoring

Dott. Giacomo Peruzzi, Dott. Ing. Davide Forcellini, Dott.ssa Karen Venturini, Prof. Dario Albarello

San Marino Historic Centre town was included in UNESCO world heritage list in 2008. The site is located in a region characterized by medium seismic hazard levels. Therefore, preventing earthquake damages is an important goal for conservation of historical buildings. From an economic point of view, this issue is fundamental in order to sustain tourism, a relevant source for the local incomes. However, effective retrofitting interventions require a reliable assessment of seismic vulnerability of single historic buildings, that is a quite complex task when old non-engineered structures are of concern. A first step in this direction is the evaluation of dynamic response to seismic loads at least in the domain of small strain levels corresponding to the beginning of damage. As several recent studies demonstrate, this task can be achieved in an efficient way by using suitable single station asynchronous ambient vibration measurements. This technique has been applied to the three middle-age towers located in San Marino and allowed identifying fundamental (elastic) resonance frequency, a key parameter for assessing seismic behaviour of historical buildings.