The Bergsøysund Bridge, built in 1992, is a 931 m long floating bridge located on the northwestern coast of Norway. The steel truss bridge, which is supported by 7 discretely distributed concrete pontoons, crosses the strait between the two islands Bergsøya and Aspøya. It is one of the longest end-supported floating bridges in the world without mooring, which makes it an interesting case study.

The main objective with the monitoring project is to study the dynamic behaviour of the floating bridge, especially the wind- and wave-induced vibrations. All data generated by the extensive measuring system will contribute to fulfil the mail goal of the research; to get a better understanding of the dynamic behaviour of different types of bridges subjected to extreme environmental loads. 

Figure 1: The Bergsøysund Bridge. Photography by K.A. Kvåle. Reproduced with permission from copyright holder, from [1].

The monitoring system consists of the following sensors (illustrated in Figures 2 and 3):

• 14 triaxial accelerometers
• 5 anemometers
• 6 wave radars
• 1 GNSS displacement sensor

Figure 2: Illustration of the top view of the Bergsøysund Bridge showing pontoons and accelerometer positions. Illustration by NTNU/ K. A. Kvåle.

Figure 3: Illustration of the front view of the Bergsøysund Bridge showing anemometer, GNSS and wave radar positions. Illustration by NTNU/ K. A. Kvåle.

The Bergsøysund Bridge monitoring project is mainly connected to the floating bridge research programme.