Monitoring of long-span bridges in Japan

Japan currently has 15 suspension bridges, three cable-stayed bridges and a truss bridge with spans over 500 m. Given the country’s exposure to earthquakes and typhoons, structural behaviour during seismic and wind loading are major concerns, so many of the bridges have been instrumented and continuously monitored since completion. This paper provides an overview of the development of monitoring of long-span bridges in Japan, with examples of effective utilisation of the monitored data. These include using data to verify design assumptions, update specifications for construction, enable active vibration control and evaluate performance and damage of structures during extreme events. Research is currently under way on how to extend the application of monitoring data for operation and maintenance.