Non-linear dynamic and static analyses on eight historical masonry towers in the North-East of Italy

• Numerical study on the seismic behavior of masonry towers.
• Non-linear dynamic and pushover analyses on detailed 3D FEM models.
• Critical insight into the results obtained and comparison on active failure mechanisms found.
• Sophisticated masonry model with distinct damage parameters in tension and compression.

The behavior of eight historical masonry towers, located in the North-East region of Italy, is analyzed under horizontal loads by means of detailed 3D FE models. The geometry of the towers is deduced from both existing available documentation and in-situ surveys. The towers, albeit unique for geometric and architectural features, show some affinities that justify a comparative analysis, as for instance the location and the similar masonry material. Their structural behavior under horizontal loads is therefore influenced by geometrical issues, such as slenderness, walls thickness, openings, presence of internal vaults and irregularities.Non-linear dynamic analyses are performed on detailed 3D FE models of the towers using a real accelerogram with different peak ground accelerations. A damage plasticity material model, exhibiting softening in both tension and compression, is used for masonry. Non-linear dynamic simulations show the high vulnerability of ancient masonry towers under horizontal loads. Numerical results are then compared with a non-linear static procedure based on pushover analyses in terms of displacement demand and tensile damage distribution. It is found that the results obtained with the non-linear static procedure are in a good agreement with those obtained through more time-consuming non-linear dynamic simulations, with a slight less conservative trend.