Application of InSAR deformation monitoring tools to study tailings dam failures

Abstract

Currently, catastrophic failures have occurred in tailings deposits that have demonstrated the importance of continuous monitoring of the constructive and operational status of these structures to improve their understanding and reduce risk. In many cases, dam failures are preceded by a series of anomalies such as: excessive deformation on the surface, the appearance of stress cracks or acceleration trends. If these are captured in time, they can be of great support for early warning systems or for activating risk mitigation procedures, which can ultimately lead to avoiding failures. Synthetic aperture radar differential interferometry (DInSAR) techniques measure surface deformation by processing the radar phase difference of at least two complex SAR images acquired at different times over the same area. These techniques are very useful for measuring deformations in tailings deposits since they provide high-precision periodic information over large areas, and can even be used in adverse weather conditions, unlike optical satellites. This article shows the results of the application of interferometric analysis of surface deformations in tailings dams, which allow the detection of outstanding deformations, acceleration trends and estimates of the moment of failure in its structures. The processing tools are applied by studying some important international failure cases of tailings deposits that have occurred in recent years. Advanced DInSAR techniques of persistent scatterers (PS InSAR) are used for the study. The results obtained are compared with complementary geotechnical studies carried out on these case studies.