Bridges

Many bridges in Australia are over 50 years old, surpassing their original design life. Increased heavy vehicle loads and higher traffic volumes have stressed these ageing structures. Additionally, modern codes of practice have become more stringent, and the materials used in these bridges have deteriorated over time, posing risks due to increased transport demand. Assessment challenges arise from simplified theoretical assessments, often resulting in poor load ratings and plausibility gaps. Balancing productivity with safety risks and asset consumption is crucial in managing these ageing infrastructures.

This paper introduces an advanced bridge monitoring solution integrating real-time measurements and cloud-based data platform. A real-life case study on a bridge constructed in the late 1960s, originally designed for H20-S16-44 (33-tonne) trucks under the Highway Bridge Design Specification, is presented. Currently, it is gazetted to carry 68.5-tonne B-doubles, raising concerns about its structural capacity. A higher-tier assessment of the superstructure for the 68-tonne B-double live load was conducted per AS 5100.7 - 2017. The real-time bridge monitoring system was implemented to assist in model calibration through control load tests (44-tonne truck and 72-tonne crane) and to understand the bridge's specific loading characteristics. Long-term monitoring provided data on axle configuration, gross vehicle mass, dynamic amplification, and the bridge's response over time. An automated overloading trigger was set to indicate acceptable structural response, with automatic alerts sent to the asset owner when exceeded. Real-time monitoring insights were invaluable for understanding critical loading events, associated bridge responses, and compliance with load restrictions, aiding risk-informed asset management.