Distributed fiber optic temperature sensors for leakage detection hydraulic structures
Résumé
Structural health monitoring of civil engineering infrastructures like dams and dikes is a vital issue because of their harsh working environments. It is inevitable to detect all kind of anomalous behavior in order to take preventive measures well in advance. Most of the failures in the embankment dams are attributed to internal erosion, the movement of soil particles under the influence of significant water flow thorough the structures. This significant flow in turn brings about a change in temperature of the structure thus making temperature a very useful measurand, containing information about leakages. The conventional techniques for surveillance of dikes are comprised of visual inspections and local measurements carried out punctually. However, subject to the constraint that these structures are spread over large distances (several tens of kilometers), semi-autonomous methods have to be employed. Distributed temperature sensors based on optical fibers present an economically viable solution in this regard. The low-cost telecommunication fiber, serving as an intrinsic sensor, is probed to obtain temperature profiles with high spatial (1 m) and temperature resolutions (0.01 to 0.1 °C). The raw temperature data being not immediately interpretable in terms of leakage detection, requires subsequent intervention of analysis techniques. In this paper, we would present the analysis methods based on advanced signal processing techniques such as source separation as well as several case studies on real experimental sites of EDF (major dam owner in France) which have successfully allowed water leakage detection
Origine : Fichiers produits par l'(les) auteur(s)
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