D-Lux: A New Way to Assess the Safety of Embankment by 3D Electrical Survey

Abstract

A new array, D-Lux, for effective safety assessment of embankment by electrical resistivity survey was proposed and an applied field case was presented. In the D-Lux array, a positive line source is placed on the upstream reservoir along the embankment and a negative line source is located at downstream, expecting the electric current would flow through the embankment in the perpendicular way and its equipotential lines are parallel to the embankment if the material is in normal state. The use of line source clearly brought out the horizontal variation of the material. Any anomalous region is displayed by modified tomography map measured between potential poles crossing the embankment. This approach provided an electric potential map by forward modeling that fitted the observed tomography map and may be converted into resistivity map for quantitative interpretation. In the field case, the qualitative potential map showed to infer the dominant flow of electric current and the quantitative resistivity map displayed the state of the core material