Overview of integrated health monitoring system installed on cable-stayed bridge and preliminary analysis of results

The Junshan Yangtze River Bridge, built in Wuhan, China in 2001, is a steel box girder cable-stayed bridge with a main span of 460m. Due to decades of service, the bridge suffered gradual degradation and some damage. Structural health monitoring has attracted worldwide attention due to its capacity of monitoring structural damage, assisting maintenance and management, and ensuring safe operation of bridges. To monitor the performance status of bridges and generate a timely safety alarm, an integrated health monitoring system has been designed and implemented on bridges. This paper provides a thorough account of the monitoring system used at the Junshan Yangtze River Bridge. It mainly focuses on the selection of monitoring variables and arrangement of sensor points, the data collection and transmission system, the data storage and management strategy, and the user interface system. All kinds of monitoring data collected under daily operation, such as vehicle load, deflection, displacement, and cable tension, are analysed. Monitoring data for an extreme condition, which involves two heavy trucks of 178 tons moving across the bridge, are also analysed. The results indicate that the monitoring system works well and that some local welded joints may experience fatigue damage.