Use of Ground-Based Interferometric Radars (GB-InRa) for Remote Real-Time Structural Health Monitoring of Civil Engineering Structures

Ageing of existing infrastructure, man-made intervention and increasing effects of climate change are prognosed to intensify the pressure on Critical Infrastructure, including natural environment, thus requiring more effective and accurate monitoring campaigns aimed to provide a continuous real-time alerting in case of potential failures. To date, monitoring activities still rely on the deployment of several contact sensors, each providing a single point measurement and requiring access to the asset to be monitored with impacts on safety and on operations. Ground-based Interferometric Radars (GB-InRa) provide remote sensing capability allowing to monitor wide areas or structures in their entirety and without the need to place any contact sensors; thanks to its intrinsic characteristics, Radar Interferometry can be a fundamental asset to guarantee a 24/7 accurate monitoring of critical infrastructures, having continuous information on failure precursors; in addition, GB-InRa is able to detect even the smallest vibrations of the structure, providing real-time information on natural frequencies, Structural Health Monitoring and Operational Modal Analysis. This article is aimed to provide a series of case studies in which InRa technology proved its effectiveness, with a specific focus on bridge monitoring.