Dynamic Characterisation and Seismic Vulnerability Assessment of Existing Masonry Port Structures

This paper focuses on the dynamic identification and the seismic vulnerability assessment of an existing masonry port structure located in Livorno (Italy), which is a former railway station bombed and reconstructed after WWII. To this end, a historical-critical analysis, and an investigation and testing campaign has been carried out, along with a number of Ambient Vibration Tests (AVT). According to the Operational Modal Analysis (OMA), a Frequency Domain Decomposition (FDD) algorithm has been leveraged for dynamic identification. The severe noise around the harbour area and the poor soil quality make it difficult to identify the modal parameters of the structure, even if specific signal processing techniques were applied to remove the interferences. Although a ground sensor is not needed for output-only identification, it has been useful to identify a local phenomenon that it would have been arduous to figure out without its support. The investigations and the test outputs have been the baseline to create a finite element model, although not reproducing the real structural behaviour of some simplifying assumptions. However, the dynamic Structural Health Monitoring (SHM) outcomes have not been leveraged to calibrate it. A Modal Response Spectrum Analysis (MRSA) and a non-linear static (Pushover) analysis (POA) have been carried out to determine the structure capacity, and thus the Seismic Vulnerability Index (SVI) of the simplified model.