A Three Dimensional Model for Vulnerability Analyses of Slender Masonry Medieval Towers

A fibre model to describe the global dynamic response of slender masonry towers is presented for use in deterministic vulnerability analysis. The main stresses are axial in this type of structure, and coupling between flexural and axial modes in the inelastic region may be critical. The model accounts for the three-dimensional response of the structure and the relations between coupling effects and masonry characteristics. An exhaustive parametric study revealed that compression strength and height are the most important parameters determining global response to seismic excitation, and that the response is often very sensitive to the vertical component of the ground motion. The combination of flexural and axial vibrations can induce serious additional damage that should be considered in seismic risk analysis.