Definition of seismic input for structural safety evaluation : two case studies: seismic response of concrete dams; dynamic soil-structure interaction of the Leaning Tower of Pisa

The definition of the seismic input is an essential step for the evaluation of the dynamic response of structures. Strategic structures like dams or monumental buildings which are part of the architectural heritage require a specific study in order to evaluate the seismic input, especially in a country with medium-high seismicity like Italy. This work uses a hybrid approach for the evaluation of the seismic hazard, by matching the probabilistic and deterministic methods in order to obtain a controlling earthquake. The geophysical parameters of this event are then used for the selection and adjustment of spectrum-compatible accelerograms. The procedure is applied to two case studies: the first is represented by two concrete dams, for which the dynamic response is evaluated through a step-by-step method: starting from simplified analyses to obtain dam base sliding to more accurate analyses which can allow an estimate of the expected damage on the structure. The second case study the dynamic response of the Leaning Tower of Pisa is assessed, first through an identification of the critical issues in the existing studies on the topic, then by defining the seismic input considering soil-structure interaction and the recent geophysical tests performed in the Square of Miracles.