Monitoring the Vibration Response of the School of Engineering Main Building at University of Naples “Federico II” to an “Earthquake of Joy"

TheSchoolofEngineeringMainBuildingoftheUniversityofNaples “Federico II” has been for years the core of an experimental research in the area of the structural monitoring aimed at the seismic risk mitigation and management. It is a relevant scientific and technical problem still of current interest, especially because it is a building characterized by a relevant architectural value located nearby the Campi Flegrei, a large and active volcanic area. It is also located nearby the Diego Armando Maradona Stadium, the home stadium of the S.S.C. Napoli football team. During one of the key events of the Serie A season, a monitoring system was installed aimed at analyzing the vibration response of the building under the excitation of about hundred thousand people inside and outside the Maradona Stadium. Data have been processed according to different approaches to put in evidence the amount and variety of information that can be obtained from a vibration-based structural and seismic monitoring system. The results show that the response amplitude is influenced by the operational loading caused by the supporters of the local football team when approaching the stadium and during the match. Such a loading shows characters common to an input ground motion but with a significant influence of the random excitation due to the surrounding environment. In fact, the input due to the supporters jumping in the stadium is characterized by a dominant frequency component and some directionality, but with a significant random response superimposed to it. The vibrations at the ground of the building as well as those measured at the upper floors have been therefore processed to characterize the input as well as structural response in these unique operational conditions.