Earthquake-Induced Damage Localization and Quantification in Historic Masonry Towers Using OMA and IDA

In the context of relevant seismic events that recently hit Italy, like L’Aquila 2009, Emilia 2012 and the Central Italy seismic sequence 2016, there has been an increasing scientific interest on Cultural Heritage buildings’ assessment, with key concepts like the preventive conservation and condition-based maintenance. In this regards, low-cost and non-destructive vibration-based Structural Health Monitoring systems can provide very useful information on the global dynamic and structural behavior, enabling detection of small structural damages that occurred during earthquakes, even far-field ones of moderate intensity. This paper presents a methodology aimed at addressing the rapid post-earthquake damage localization and quantification tasks in historic masonry structures, based on Operational Modal Analysis (OMA) and non-linear Incremental Dynamic Analysis (IDA). While the OMA-based damage detection approach was already presented in previous work by the authors, this paper focuses on the IDA-based part of the methodology. Validation is presented through application to a medieval masonry structure: the bell tower of the Basilica of San Pietro located in Perugia, Italy. It is a monumental Cultural Heritage (CH) building permanently monitored since December 2014. The numerical FEM model together with experimental continuous vibration data and those recorded during the 2016 Central Italy seismic events are successfully exploited for earthquake damage localization and quantification.