Dynamic behaviour of a retrofitted school building subjected to the after-shock sequence of the 2016 Central Italy earthquake

This paper deals with the dynamic behaviour of a 1960s school building in Camerino subjected to moderate earthquakes belonging to the after-shock sequence of the 2016 Central Italy earthquake. The school structure, constituted by RC frames, was seismically retrofitted by means of "Dissipative Towers", an innovative system based on the use of external stiff steel truss towers equipped with dissipative dampers. Modal properties of the building after the retrofit have been determined through ambient vibration tests. After the main shock of the 2016 Central Italy earthquake, the building was instrumented with low-noise accelerometers and the dynamic behaviour of the structure during several aftershocks was recorded. Firstly, a numerical finite element model of the building is developed and calibrated on the basis of the ambient vibration measurements; then the registered dynamic response of the structure for the highest aftershock event (among the registered ones) is compared with that obtained numerically with the calibrated model. Results demonstrate the good agreement of the registered and predicted response.