CONTINUOUS OMA FOR DAMAGE DETECTION AND LOCALIZATION IN THE SCIRI TOWER IN PERUGIA, ITALY

摘要

This paper presents a methodology for earthquake-induced damage detection and localization in masonry towers using long-term vibration monitoring data. An inverse calibration problem is solved to evaluate the evolution in time of the damage-dependent structural parameters, by using a surrogate quadratic model of natural frequencies and modal shapes. An historic civic tower, named Sciri Tower and located in Perugia, Italy, continuously monitored since December 2016, is selected as the case study. The validation of the procedure is carried out through nonlinear dynamic analyses exploiting a finite element model of the tower and of the surrounding building aggregate calibrated on the basis of data from ambient vibration tests. Accelerograms measured during real earthquakes, occurred during the monitoring period, are adopted for the simulations. The results demonstrate that the proposed procedure is capable of correctly detecting and localizing earthquake-induced damages, even in the case of small-intensity earthquakes where no significant changes in structural conditions are detected from visual inspections.