Bridge monitoring using multi-GNSS observations with high cutoff elevations: A case study

Bridges are important transport nodes and play a vital role in socio-economic development around the world. However, the extreme loadings, aging and increasing traffic volume are the factors affecting bridge serviceability. Therefore, the establishment of Structural Health Monitoring (SHM) system is extremely important to monitor the performance of bridges and help the bridge owners to make timely and right decisions. In present, Global Positioning System (GPS) technology has been widely applied as an essential part of a SHM system. With the BeiDou Navigation Satellite System (BDS) becoming available and the full operation of the GLONASS (GLObalnaya NAvigazionnaya Sputniovaya Sistema) system, multi-constellation GNSS (Global Navigation Satellite System) tends to be the best choice in the SHM systems. In this study, we propose a multi-GNSS integration processing method and present a case study on bridge monitoring using multi-GNSS observations with high cutoff elevations. Based on the experiments at the Baishazhou Yangtze River Bridge in Wuhan, China, it shows that, with more satellites available and the strongest satellite geometry, the combined GPS/BDS/GLONASS shows the highest precision with 1-2 mm horizontal and 2-5 mm vertical precision. With the integration of GPS/BDS/GLONASS, different cutoff elevations are set in data processing in the application of bridge monitoring. The result demonstrates that the precision in horizontal component can always achieve to 1-2 mm with the cutoff elevation angles rising (from 10 degrees to 40 degrees), even when 40 degrees is selected. Finally, a vibration test was carried out at different cutoff elevations (from 10 degrees to 40 degrees). It shows that the displacement and vibration signals can be extracted extremely well with the integrated GPS/BDS/GLONASS at cutoff elevation of 40 degrees. A high cutoff elevation therefore could be set in bridge monitoring applications to increase the GNSS applicability in constrained environments.

Automated summary

The study demonstrates that integrated GPS/BDS/GLONASS provides the highest precision in bridge monitoring, especially with high cutoff elevations due to the availability of more satellites and strongest satellite geometry. Further experiments conducted show that incorporating GPS/BDS/GLONASS at a cutoff elevation of 40 degrees allows for extremely accurate extraction of displacement and vibration signals in bridge monitoring applications.