Dynamic Test Based Model Calibration of an Existing R.C. School Building

This paper deals with the dynamic tests carried out on a school building seismically retrofitted with an innovative system that uses external steel dissipative towers. Before the retrofitting, ambient vibration tests were carried out with the aim of evaluating the modal parameters of the building including the contribution of nonstructural components to the global dynamic behavior of the structure. In particular, the contribution of non-structural components plays fundamental role in structural design because neglecting the infills in finite element models can produce macroscopic errors that may compromise the capacity of the models to predict the structural response of the structure when used for design purposes, such as for seismic retrofitting projects. In this context, the calibration of the finite element models (f.e. models) through experimental measurements plays a fundamental role in ensuring that the models reproduce with sufficient reliability the real behavior of the structure. After the building retrofitting, ambient vibration measurements were repeated to verify that variations in modal properties of the building, evaluated at very small input energy level, are in accordance with those expected from the numerical model. Furthermore, snap-back tests of the building were performed at different load levels to assess the dissipative capacity of the new structural system at greater input energy level.