An integrated experimental and numeric approach to investigate the structural dynamics of the Segesta Temple, Sicily

The Temple of Segesta, one of the oldest and best-preserved Doric temples in the Mediterranean, offers a unique case for studying the dynamic behavior of ancient masonry structures in a moderate seismic zone. This paper presents the stages leading to its dynamic characterization. A laser-scan-based geometric survey and previous investigations supported the development of a preliminary numerical model, which guided sensor placement for an extensive ambient vibration measurement campaign using twelve three-component seismic nodes across 63 positions as the basis for an Operational Modal Analysis. Twelve global vibration modes and several local modes were identified and used to calibrate finite-element models. The calibration revealed changes in elastic properties caused by degradation and past reinforcement interventions. Recordings of a teleseismic event further validated the calibrated model. The study demonstrates the value of vibration-based model updating for the non-invasive assessment of heritage structures and for future archaeoseismic investigations.