Abstract Manager

In collaboration with the Ministry of Infrastructure and Transportation of Manitoba, this study presents a novel structural health monitoring (SHM) strategy that utilizes ambient vibration testing (AVT) to evaluate bridge integrity. Despite the proven efficacy of Dynamic SHM over traditional methods, limitations persist in the ability of current approaches to localize and quantify damage or map dynamic anomalies to the physical structure. By comparing detailed measured 3D mode shapes with expected mode shapes from a database of AVTs across all bridge types, the framework in this study establishes a non-intrusive method to enable damage detection and quantification.

Ambient vibration data was collected via wireless, high-resolution sensors at 132 locations on the PR204 Red River Selkirk Bridge (a 1935 steel structure) to extract its dynamic properties. Results demonstrated that the extracted 3D mode shapes can successfully locate and quantify structural anomalies within key components, including piers, trussing members, bearings, and deck members. The effect of repair was also captured in the dynamic properties extracted before and after the rehabilitation process for a specific component, the south bottom chord of span 4.

Conducting periodic one-day AVTs enables the tracking of structural deterioration rates over time. This provides bridge owners with data-driven insights to effectively plan for future rehabilitation or replacement. Distinguished from traditional inspections and permanent SHM systems, this approach offers a robust, scalable solution that eliminates the need for long-term installations or existing structural drawings. Ultimately, the proposed approach supports targeted maintenance and performance-based asset management, helping to extend service life and improve decision-making in bridge infrastructure management.

Keywords: Ambient vibration testing, bridge health monitoring, measured mode shapes, periodic testing, dynamic stiffness evaluation