Harnessing AI to revolutionise bridge condition assessments

Purewa Bridge, in Ōrākei, is a 100-year-old concrete bridge that connects Auckland’s Eastern suburbs to the central city and carries more than 20,000 vehicles per day. Using AI to inspect the bridge was a game-changer.

In 2023, Auckland Transport identified a requirement for a preliminary condition assessment of the Purewa Bridge to establish the scope of repairs needed.

Traditionally, bridge inspections are manual, time-consuming and disruptive to traffic. But our Transport & Infrastructure team recommended trialling an AI technology solution which, in comparison, is safer, faster, more accurate, more economical, and less disruptive.

This revolutionary new process utilised AI-enabled drones fitted with high-definition cameras to capture high-resolution images and then used AI software to automatically identify and quantify defects such as cracks, spalls and honeycombing, including those that are incredibly small. In total, 15,000 photos and acoustic soundings, from multiple angles and heights, were taken from the bridge piers, underdeck and longitudinal beams. The AI tools and software used to assess and quantify defects were provided by Niricson.

As a result, the digital condition assessment, including 3D modelling, was able to be delivered to Auckland Transport in a much shorter time frame and with greater accuracy than previously, with no traffic disruption.  

With over 20,000 concrete bridges across New Zealand, AI has the potential to be a game changer for bridge inspections and repairs.