<p>Bridges and viaducts are exposed to a variety of threats that can affect their operations and structural integrity [1]. Recent unexpected collapses and failures of bridges underline the need for effective structural monitoring, particularly for reinforced concrete structures. In fact, once distress mechanisms are triggered, these can deteriorate faster than the time required for rehabilitation, strengthening, or replacement.</p><p>To this extent, it is evident that the monitoring of the actual health conditions of the existing bridges is a priority for asset operators in order to guarantee the structural integrity, the safety of the operations and preventing irreversible damages or even structural collapses.</p><p>Within this context, Non-Destructive Testing (NDT) methods such as Ground Penetrating Radar (GPR) and Terrestrial Laser Scanner (TLS) amongst many others have been used for the assessing and monitoring such structures in the past few years[2]. However, topic-related studies [3-4] have demonstrated that stand-alone use of ground-based techniques may not represent a definitive solution to particular major structural issues, such as scour and differential settlements, as these require continuous monitoring and data collection on long-term bases . To that extent, the use of satellite-based remote sensing techniques, such as Synthetic Aperture Radar Interferometry (InSAR), have proven to be effective in detecting displacements with a millimetre accuracy along with transport infrastructures [3-5] and natural terrain considering long periods of observation.</p><p>Accordingly, this research aims to present a novel integrated monitoring approach including the use of ground-based technologies (GPR, TLS) and the InSAR techniques over a Maillart arch type bridge: the Viadotto Olivieri in Salerno, (in the South of Italy).</p><p>Main objectives of the research &#160;are: (1) to prove the viability of low-frequency and high-frequency GPR systems in providing structural detailing of the bridge-deck at different depths and resolutions; (2) to measure seasonal structural displacements with a millimetre accuracy to detect potential critical issues of the bridge.</p><p>The outcomes of this study, under the National Project &#8220;EXTRA TN&#8221;, PRIN 2017- Prot. 20179BP4SM, demonstrate how multi-temporal InSAR remote sensing techniques can be synergistically applied to complement the traditional ground-based surveys.</p><p>&#160;</p><p>References</p><p>[1] Hosseini Nourzad, S. H. and Pradhan, A. Vulnerability of Infrastructure Systems: Macroscopic Analysis of Critical Disruptions on Road Networks. Journal of Infrastructure Systems, 22(1), 04015014. 2016</p><p>[2] D&#8217;Aranno, P., Di Benedetto, A., Fiani, M., and Marsella, M.: Remote Sensing Technologies For Linear Infrastructure Monitoring, Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-2/W11, 461&#8211;468, https://doi.org/10.5194/isprs-archives-XLII-2-W11-461-2019, 2019.</p><p>[3] Bianchini Ciampoli, L., Gagliardi, V., Clementini, et al., Transport Infrastructure Monitoring by InSAR and GPR Data Fusion. Surv Geophys 41, 371&#8211;394 (2020). https://doi.org/10.1007/s10712-019-09563-7</p><p>[4] Gagliardi V., Benedetto A., Bianchini Ciampoli L., D&#8217;Amico F., Alani A., Tosti F., 2020. Health monitoring approach for transport infrastructure and bridges by satellite remote sensing Persistent Scatterer Interferometry (PSI). Proc.SPIE 11534. https://doi.org/10.1117/12.2572395</p><p>[5] Bianchini Ciampoli L., Gagliardi V., Calvi A., D&#8217;Amico F., Tosti F., Automatic network-level bridge monitoring by integration of InSAR and GIS catalogues. Proceedings of SPIE - The International Society for Optical Engineering, 11059, (2019). DOI: 10.1117/12.2527299</p>
The VEI 2 Christmas 2018 Etna Eruption: A Small But Intense Eruptive Event or the Starting Phase of a Larger One?
