Analysis of seismic soil – structure interaction for a high monumental tower in Naples (Italy) under a historical earthquake

The paper examines the effects of soil-structure interaction on the dynamic behavior of the historical Carmine bell tower in Naples, damaged by the Sannio earthquake in 1456. The brickwork structure is 68m tall, endowed with direct foundations on a deformable deposit of man-made ground and alluvial sands, overlying volcanic tuff. The structural model was calibrated on existing data, the foundation and the geotechnical subsoil model were reconstructed according to recent investigations. Soil-structure interaction was simulated by simplified and advanced approaches, considering the input motion determined through seismic response analyses. The seismic action on the rock outcrop was defined, simulating the 1456 earthquake. Comparing the results of the analyses on the fixed based structure with those of soil–structure system, the effects of the interaction was recognized in terms of elongation of the period, reduction of the damping and increase of structural displacements due to the rigid rotation of the base.