Dynamic Characteristics and Rocking Response of a Byzantine Medieval Tower

This investigation deals with the dynamic response of a Byzantine unreinforced masonry tower. The tower is located on Mount Athos and was erected in 1427. It was built to host the bells of Vatopedion Monastery and is 25 m tall. It has suffered several earthquakes during its history, and some restoration interventions have been applied. Firstly, the architectural characteristics are considered in the light of seismic events that hit the monument. Then, the modal characteristics are investigated using a linear analysis. Finally, the limit analysis is adopted to examine the behaviour of the tower up to collapse due to out-of-plane failure. A force-based and a displacement-based method are applied, and the respective capacities are converted into spectral quantities using properties of the first mode. Possible collapse mechanisms are considered in conjunction with the observed after-shock damage. The safety factor is derived comparing the capacity curves with the considered spectra.