Infrastructure2023
Bridge Substructure Condition Assessment
South Brisbane
Overview
Condition assessment of reinforced concrete bridge substructure elements including piers, headstocks, and abutments. The bridge was approaching its 40-year design life and required assessment for life extension. Half-cell potential mapping identified active corrosion zones concentrated on the tidal splash zone of piers. Chloride profiling and durability modelling predicted remaining service life for each element, informing a prioritised maintenance programme.
Challenges
- 01Access to substructure elements required under-bridge inspection units
- 02Tidal zone access limited to specific tide windows
- 03Testing programme needed to cover 24 pier elements across 6 spans
- 04Results required for asset management budget submission within 8 weeks
Outcomes
- 01Remaining service life estimated at 15 to 25 years for most elements
- 024 pier elements required priority cathodic protection within 2 years
- 03Provided 20-year maintenance cost forecast for asset planning
- 04Enabled life extension decision avoiding early replacement at $40M+ saving