Monitoring deformations of bridge portfolios using satellite MTInSAR

Andrea Nettis¹, Vincenzo Massimi², Raffaele Nutricato³, Davide Oscar Nitti³, Sergio Samarelli², Giuseppina Uva¹

¹ Dipartimento di Ingegneria Civile, Ambientale, Territoriale, Edile e di Chimica, Politecnico di Bari, Bari, Italy

² PLANETEK ITALIA s.r.l., Bari, Italy

³ Geophysical Applications Processing s.r.l, Bari, Italy

Abstract. Managing transportation network authorities need to address targeted monitoring and structural assessment on appropriately selected critical bridges to improve the serviceability and safety of the network optimising the involved financial budgets and resources. The multi-temporal satellite-based differential interferometry, commonly referred to as MTInSAR, is a remote-sensing technique aimed at detecting displacements of coherent scatterers on the terrestrial surface with centimetre- to millimetre-level accuracy. Several recent literature studies [1]-[4] discuss the potential of MTInSAR for structural monitoring with the aim to promote the practical and daily application of this technique by transportation authorities' operators. This paper applies an MTInSAR-based methodology for the portfolio-scale evaluation of deformation phenomena on bridges, suitable for addressing targeted sensor-based monitoring or on-site inspection plans. Within the proposed methodology, the displacement time-series associated with persistent scatterers on the investigated bridges are used to supply a geoprocessing chain, implemented in geographical information systems, leading to the automatic interpretation of bridge-specific deformation scenarios and the definition of monitoring/assessment priority classes. The methodology is applied to two highway networks in Roma and Bari (Italy). The suitability of Sentinel-1 (C-band) and COSMO-SkyMed (X-band) satellite datasets is discussed. Although most of the bridges can be assumed stable, a relevant number of bridges affected by ongoing deformation phenomena are observed and associated with high inspection priority. The MTInSAR products and the deformation scenarios related to some specific test bridges subjected to subsidence phenomena are analysed and described in detail.

Keywords. Structural health monitoring, MTInSAR, satellite interferometry, persistent scatterer, structural deformations

References.

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[3]         D. A. Talledo et al., "Satellite radar interferometry: Potential and limitations for structural assessment and monitoring," J. Build. Eng., 2022, doi: 10.1016/j.jobe.2021.103756.

[4]         E. Farneti et al., "A method for structural monitoring of multispan bridges using satellite InSAR data with uncertainty quantification and its pre-collapse application to the Albiano-Magra Bridge in Italy," Struct. Heal. Monit., 2022, doi: 10.1177/14759217221083609.