Performance monitoring of assembled beam bridges using displacement spectrum similarity measure.

This article focuses on the development and validation of the Displacement Spectrum Similarity Measure (DSSM) index for continuous condition assessment of transverse connections in assembled beam bridges. DSSM, defined as the correlation coefficient of displacement spectra between adjacent precast beams, has been shown through numerical simulations and real-world application to be robust against measurement errors (modeled as Gaussian white noise) and insensitive to deck pavement damage, while remaining sensitive to changes in transverse connection stiffness. The index was implemented on the Tongji Road Viaduct in Shanghai, where its damage diagnosis closely matched on-site visual inspections, demonstrating its effectiveness for long-term, real-time structural health monitoring with minimal manual intervention. Limitations include dependence on traffic flow stationarity for convergence and potential insensitivity to damage distant from sensor locations, suggesting that combining DSSM with other methods or increasing sensor deployment could enhance diagnostic comprehensiveness.