BRIDGE THE GAP: UPGRADING THE BRIDGE HEALTH MONITORING WITH SYNTHETIC APERTURE RADAR DATA PROCESSING DRIVEN BY STRUCTURAL MODELLING
Progetto On December 2021, the European Commission launched the Global
Gateway strategy to boost smart, clean and secure links in
digital, energy and transport sectors. Transport networks (TN) are
recognized as critical enablers of prosperous economies and
societies because their security underpins the resilience of the global
economy and supply chains. The security of TN is a current
priority and it strongly relies on the security of its components. Among
others, bridges can be considered as the TN weakest-link, due
to their high vulnerability to natural and man-made hazards and deterioration
rate over time. Indeed, the infrastructure managers
are putting huge efforts in the Structural Health Monitoring (SHM) of
bridges, with the aim of supporting their safety level.
SHM may benefit from the massive use of space technology, in particular of
Synthetic Aperture Radar (SAR) for high-resolution
monitoring of structures from satellite platforms by exploiting the multipass
Differential Interferometry techniques and specifically
focusing on SAR Tomography. This technique allows implementing a fine
beam radar scanner from space to accurately inspect in 3D
and monitor the surface of infrastructures up to the finest details; the
advantage over standard interferometric approaches is in
terms of higher accuracy and density of monitored points.
Among others, bridges still represent a critical scenario for the deployment
of SAR based techniques. Decades of processing of very high-resolution data
stressed that these approaches fail to ensure optimal coverage as the bridge
length increases and some gaps
arise in the spatial coverage.
Indeed, the deformation of long-span bridges is significantly affected by the
structural configuration (bridge typology, boundary
conditions, end-support, material, geometry, etc) and by external actions
(traffic loads, temperature variation and wind).
Deformation models exploited in SAR interferometric processing, actually
do not incorporate the specific bridge characteristics,
whereas their consideration could provide an enhanced prediction and a
better detection and interpretation of measured
displacement trends.
At the light of these considerations, the main goal of this proposal is to
develop a coupled integrated approach, between SAR signal
processing and structural engineering, to include the information provided
by a numerical structural modeling in the SAR
Tomography phase models. The focus is on long-span and multi-span
bridges. A set of bridges has been pre-selected considering
both the availability of long-term very high resolution COSMO-SkyMED
SAR archives and the suitability of the structural typology.
Detailed analyses over two case studies will be firstly addressed. Then a
blind prediction over other bridges will be performed, to
evaluate the portability of the research findings over large areas.