Surrogate models for earthquake-induced damage detection and localization in historic structures using long-term dynamic monitoring data: Application to a masonry dome

In the last decades, the increasing need of preservation of historical constructions against strong actions and materials ageing (e.g. environmental and weathering actions, earthquakes) have induced to develop new strategies aimed at the detection of possible criticalities which could occur during the life of the constructions. The continuous dynamic monitoring is revealing as an efficient practice able to rapidly identify structural anomalies related to damages suddenly and/or increasingly developed. Within this context, the application of specific procedures for damage detection and localization, especially in the cases of historical constructions, such as palaces and churches, is still a challenge owing to the computational burden for the management of complex numerical models. The use of surrogate models calibrated on more refined numerical ones allows to overcome this computational issue and to process the monitoring data in a more efficient way. The aim of this work is to define accurate surrogate models calibrated on a more refined Finite Element Model of the Basilica of Santa Maria degli Angeli in Assisi, able to reproduce its main modal parameters as functions of the equivalent elastic constants of macro-regions of the structure. Moreover, the results obtained by the installation of a long-term dynamic monitoring system in the same monumental Basilica are used to investigate the effectiveness of damage localization procedures when applied to the data recorded during the Central Italy seismic sequence of 2016-2017. In particular, the results highlight a good agreement between the estimated damage and the outcomes of visual inspections made on site after seismic events.