Abstract
After years of research and development, the structural health monitoring system for the Seohae Bridge was installed in 2000 in South Korea. This steel–concrete composite cable-stayed bridge has a main span of 470 m. To monitor the long-term structural behavior and anomalies of the bridge, the system was composed of hundreds of sensors, including accelerometers, anemometers, and strain gauges. These sensors were installed on critical elements of the bridge, such as the stay cables, a stiffening girder, and the main pylons. After the development and stabilization phase, which lasted almost a year, the system has been successfully operated and has helped in understanding the structural characteristics and long-term behavior of the bridge. After more than 9 years of operation, however, the system started to show signs of aging and deterioration. Some gauges and sensors have worn out and have become malfunctioning. To fix these problems and upgrade the system, the renovation work was planned and carried out with a budget estimated at US$2 million. The main goals of the renovation work were to optimize sensor deployments, improve graphical user interfaces, and deploy state-of-the-art sensors and technologies. Although the number and types of sensors were minimized, a monitoring system based on a global navigational satellite system was newly installed to monitor deformation and geometry change of the bridge.