Structural characterization of an arch bridge in Italy using wave propagation analysis

In this study, the main structural characteristics of an arch bridge have been identified using the ambient noise deconvolution interferometry (ANDI), based on wave propagation analysis. The proposed approach has been applied to the 'Langer' Gravina Bridge located in Matera (Southern Italy). The ‘Gravina’ is a 144 m long bow-string arch bridge with a base isolation system constructed on outcropping calcarenites. Two ambient vibration measurement campaigns were performed to characterise the dynamic behaviour of the road infrastructure. First, a brief structural description of the bridge and the experimental setup is provided and, second, the results are presented and discussed. Modal analysis has been carried out using the Frequency Domain Decomposition (FDD) method, a non-parametric identification technique to estimate the modal properties (eigenfrequencies and mode shapes). The deconvolved wavefields and the wave propagation velocities are determined by an interferometric approach along the main bridge axes. The interpretation of the deconvolved wavefield is facilitated using the results obtained from FDD.