Time-lapse electrical resistivity tomography characterization for piping detection in earthen dam model of a sandbox

Early detection of piping in earthen darns is critical in preventing substantial damage due to dam failure. Although it is significantly difficult to directly identify piping caused by subsurface seepage and soil erosion, these subsurface phenomena are indirectly detectable from electrical property changes using the electrical resistivity tomography (ERT) method. We thus demonstrate the applicability of time-lapse ERT measurements for the early detection of dam failure by characterizing temporal changes in subsurface behaviors via sandbox experiments of an earthen dam model. Boundary artifacts caused by the walls of the sandbox can potentially be mitigated by systematic numerical experiments. Time-lapse resistivity models and resistivity change ratio images allow for visualization of water content changes and the occurrence of empty space related to surface behaviors. We believe that the time-lapse ERT method is an effective method for monitoring piping in earthen dams. (C) 2019 Elsevier B.V. All rights reserved.