Assessment of the seismic vulnerability of medieval defensive walls toward out-of-plane mechanisms

Medieval defensive walls characterize many Italian historical towns. These structures, representing an important part of the cultural heritage, are frequently affected by damages (cracks, settlements or out-of-plumb) that could particularly compromise their structural safety level, especially in case of the occurrence of seismic events. The preservation of these structures is then a topic of particular relevance. The paper presents a study concerning the assessment of the capacity of medieval defensive walls toward seismic actions with reference to the possible occurrence of out-of-plane mechanisms. To this end, a preliminary exam concerning the common typologies of defensive walls and, more in detail, the main parameters influencing their response toward seismic actions, is carried out. Then, the application of the kinematic analysis is applied to defensive walls by specifically considering the presence of damage scenarios mainly consisting of out-of-plumb configurations.