Capabilities of SAR interferometry (InSAR) were demonstrated to the Czech Road and Motorway Directorate on multiple highway bridges in the Czech Republic. Pilots have been conducted in the framework of applied research project funded by the BETA Programme of Public procurement in research, experimental development and innovation for the government and the pre-operational feasibility studies were funded by the Czech Road and Motorway Directorate.
Mr. Jan Kolomaznik, project manager of GISAT, takes the Best Czech Applied Research Project Award from Mr. Andrej Babis, the Czech Prime Minister (right), and Mr. Petr Konvalinka, the Chairperson of the Technology Agency of the Czech Republic (left).
Interferometric deformation model considered complex construction behaviour assuming both linear displacements and cyclic thermal dilations as a result of temperature fluctuations. Various deformation behaviours were detected for different bridges and parts of their construction as a result of variability of bridge constructions, structural stability and orientation. The most notable deformations were detected especially in areas of bridge closures, which generally suffer from high subsidence rates resulting from compaction of subsoil material. These deformations affect adjoining parts of bridge construction and require regular monitoring followed by corrective measures (e.g. rectifications). Furthermore, it has been proved that both these subsidence and uplift deformations resulting from subsoil swelling can be also monitored indirectly by detecting displacements of supporting walls and noise barriers attached to the road body.
Cross-validation of InSAR results obtained by analysis of Sentinel-1 (left) and VHR SAR (right). D1-433 bridge, Czech Republic
Apart from demonstration cases comprehensive methodology for feasibility assessment of transport infrastructure InSAR based monitoring was prepared. In addition, suitable Artificial Corner Reflectors (ACRs) were designed, manufactured and installed as the attachment to bridge construction in compliance to requirements of the Directorate and applicable legal scope.
In the frame of this research project Gisat has introduced the methodology aiming at provision of common framework for selection of interferometric data and methods in support of subsidence and deformation risk monitoring within the transportation sector by means of persistent scatterers interferometry. Development of sustainable services based on InSAR approach shall provide temporally-rich information and cost-effective tools supporting early detection of potential risks and threads related to operation of transportation infrastructure in the Czech Republic.
Gisat provides wide range of geoinformation services based on Earth Observation technology. It focuses on operational application of satellite mapping to monitor various aspects of our environment and development of dedicated web based platforms for geoinformation analysis and assessment.
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