Modal Analysis for the Rehabilitation Assessment of the Luiz I Bridge

A recent modal analysis of the Luiz I Bridge, a historic steel-arch bridge in Porto, Portugal, revealed significant changes in its dynamic properties following rehabilitation and strengthening. The study compared ambient vibration data collected before and after construction works, highlighting variations in stiffness and modal parameters. These findings challenge the necessity for mandatory static field testing by demonstrating that dynamic testing alone can effectively assess structural behavior post-rehabilitation. Researchers used experimentally validated 3D finite-element models to simulate both phases, providing insights into how support conditions and deck structures influence bridge dynamics. This dual-testing approach offers a valuable method for verifying predicted behavior during design stages.

Costa, B. J. A., Magalhães, F., Cunha, Á., & Figueiras, J. (2014). Modal Analysis for the Rehabilitation Assessment of the Luiz I Bridge. Journal of Bridge Engineering, 19(12). https://doi.org/10.1061/(asce)be.1943-5592.0000632