Utilisation de la fibre optique comme capteur géophysique – Applications ferroviaires

The quality of the railway platform is crucial for operational performance, particularly in terms of safety and efficiency. It provides the infrastructure with a foundation whose stability ensures the maintenance of track geometry for suitable operating speeds. The quality of the platform depends on the mechanical properties of the materials used and the associated processes. It also relies on the properties of the surrounding soils. During the design phase, these characteristics are controlled, but they may degrade over time due to the stresses incurred by passing trains, weather conditions, or climate change.

To monitor these elements, the infrastructure manager has various human, technical, and experimental means at their disposal. However, this monitoring is a significant challenge as it requires substantial resource mobilization. To enhance this surveillance, Distributed Acoustic Sensing (DAS) has proven to be a highly promising tool, as a single interrogator can gather information over 50-100km of cable. The primary objective is to develop and adapt methodologies that utilize surface waves generated by passing trains and DAS to monitor the mechanical properties of the subsoil beneath the tracks.