Shallow subsurface rail track imaging from train noise recorded at existing distributed acoustic sensing (DAS) installations

We demonstrate the practical feasibility of shallow shear wave velocity imaging based on ‘dark fiber’ – DAS recordings using trains as sources. Results from a case study in Europe allow for the interpretation of potential geologic hazards and other features relevant for assessing the geotechnical integrity of the rail infrastructure. This approach does not require dedicated field measurements or interruption of the train schedule, and therefore represents a cost-effective and robust method for different application scenarios.