Bridge health monitoring is a method of evaluating the ability of a bridge to perform its required task (also called fitness for purpose) by monitoring the response of the bridge to the traffic loads it has to withstand.
This research project, carried out in 1998–1999, is part of stage 2 of the short-term health monitoring and 'fitness for purpose' assessment of 10 bridges on New Zealand highways, in order to develop and evaluate the methodology. The Waipara Bridge, on State Highway 1S, crosses the Waipara River about 60 km north of Christchurch, Canterbury region, South Island. It was selected as one of these 10 because it is a prestressed concrete structure, with a conventional strength evaluation that indicates adequate strength. It has been in service since 1971, and is typical of a large population of prestressed concrete bridges in New Zealand. It has a significant replacement value as part of New Zealand’s transport infrastructure. The fitness for purpose evaluation indicates that web shear capacity of the main girders governs the capacity of the bridge.