Monitoring the Sunshine Skyway Bridge

Carrying I-275 over Tampa Bay, the Bob Graham Sunshine Skyway Bridge is a cable-stayed structure that plays a vital role in Florida’s transportation network. To support long-term performance monitoring and asset management, the Florida Department of Transportation (FDOT) contracted BDI to install a structural health monitoring system focused on capturing vibration behavior of the bridge.

BDI instrumented one fan of stay cables, the adjacent tower, and the bridge deck with triaxial accelerometers to provide insight into the response of the bridge. To complement structural instrumentation, environmental sensors including an anemometer, temperature and humidity probe, and a ‘tipping bucket’ rain gauge were deployed to correlate collected data with weather conditions.

All instrumentation equipment was specified in accordance with FDOT contract requirements and configured to operate remotely. BDI developed specialized processing software to store only the frequency content of the acceleration data instead of full time-histories in order to reduce the data volumes and facilitate data management. The system automatically records, processes, and transmits collected data, allowing FDOT access to view, download, and analyze measurements as needed.

This monitoring setup provides FDOT engineers with the data needed to periodically perform cable force calculations to assess the performance of stay-cable components. Additionally, the system plays a vital role during hurricanes, providing real-time structural and environmental data to help FDOT make informed decisions about bridge closures and reopening.