The intelligent Distributed Acoustic Sensor (iDAS™) can provide critical information on the health of geotechnical structures such as levees, dams, geothermal reservoirs, pipelines.
Transforming a fibre optic cable into a seismic array of unparalleled density, iDAS allows to monitor both ambient-noise-based and stimulated seismicity.
Deploying a fibre optic cable in a shallow subsurface of any geotechnical structure allows for near surface seismic techniques, such as Multichannel Analysis of Surface Waves (MASW) and ambient noise interferometry, to be applied. The information extracted enables to characterise the top 20-40m from the soil surface at unprecedented spatiotemporal resolution and spatial range, while the high time-lapse repeatability of the iDAS allows to detect the appearance of anomalies.
iDAS can localise areas of relative velocity variations of seismic waves imputable to increase/decrease of fluid saturation of soil, as in the case of liquid spilling out of buried pipes, and seepage variations in dams.
Continuous iDAS monitoring can use ambient-noise to detect early changes from the anticipated response of the geotechnical structure, increasing safety and improving the structure maintenance.