Structural and Seismic Monitoring of a Monumental Building: the Case Study of the Royal Castle of Racconigi

Abstract

Abstract. The stability of an arch as a structural element in the thermal bath of King Carlo Alberto in the Royal Castle of Racconigi (on the UNESCO World Heritage List since 1997) was assessed by the Acoustic Emission (AE) monitoring technique with application of classical inversion methods to recorded AE data. First, damage source location by means of triangulation techniques and signal frequency analysis were carried out. Then, the recently introduced method of natural time analysis was preliminarily applied to the AE time series in order to reveal possible entrance point to a critical state of the monitored structural element. Finally, possible influence of the local seismic and micro-seismic activity on the stability of the monitored structure was investigated. The criterion to select relevant earthquakes was based on the estimation of the size of earthquake preparation zones. The presented results suggest the use of AE technique as a tool for detecting both ongoing structural damage processes and micro-seismic activity during preparation stages of seismic events.