Monitoring of a multi‐span prestressed concrete bridge using satellite interferometric data and comparison with on‐site sensor results

Satellite-based Synthetic Aperture Radar Interferometry (InSAR) represents a promising supplement to traditional Structural Health Monitoring (SHM) methods, offering a non-invasive solution that eliminates the need for sensor installations and provides extensive spatial coverage. The European Ground Motion Service (EGMS), developed by the European Space Agency under the Copernicus program, marks a significant advancement in monitoring capabilities. EGMS utilizes data from Sentinel-1 satellites and employs InSAR techniques to generate displacement maps covering the European territory. This paper aims to investigate the behavior of the Schottwien Viaduct on the S6 Semmering motorway in Austria, using EGMS data. This multi-span viaduct, measuring 632 m in length, stands as one of the longest prestressed concrete beam bridges in Austria. Environmental factors, such as temperature, are analyzed alongside satellite data to evaluate their influence on bridge displacements. The findings indicate consistent displacement patterns associated with temperature, enabling the estimation of thermal expansion coefficients that align with expected values for concrete. Two distinct InSAR data processing methods are applied, both producing comparable outcomes. Additionally, the reconstructed structural displacements closely match those obtained from an on-site static monitoring system. These findings highlight the potential of InSAR data for SHM purposes.