Non-linear analysis of the Carmine bell tower under seismic actions accounting for soil–foundation–structure interaction

The paper discusses the effect of the soil–foundation–structure interaction on the seismic assessment of the tallest monumental tower in Napoli under the historical earthquake which severely damaged the structure in 1456. To this aim, a detailed characterization of the soil, the foundation and the structure and an accurate definition of synthetic and recorded input motions were carried out. The effects on the non-linear response of the structure due to the soil compliance and the lateral restraint exerted by the surrounding buildings were firstly evaluated through non-linear static (push-over) analyses. The resulting capacity displacements were compared to the demand associated to the historical earthquake and computed through one dimensional seismic response analyses. A beneficial effect of the soil is shown on the seismic performance, when the lateral restraint is neglected. Non-linear dynamic analyses were later carried out on the complete soil–foundation–structural model, leading to the same failure mechanisms for the structure observed in the push-over analysis and, in some cases, the collapse of the foundation and the soil. Furthermore, an amplification of the acceleration was recognized below the foundation with respect to the free-field conditions. The results give the chance to compare the non-linear static and dynamic analyses taking into account the soil–foundation–structure interaction.