Apply Forward Simulations in 2D ERT Monitoring Program of a New Embankment Dam

Abstract

Resistivity method is generally considered suitable for investigation of seepage problems in earthen embankments. Construction of a large embankment dam in Taiwan was recently completed, providing a good opportunity for ERT monitoring of the entire water filling process and future performance. The proposed monitoring program consists of longitudinal ERT survey lines on the crest and downstream shell. One transverse survey line was added to study the seepage behavior during water filling. 2D ERT investigation on many geo-engineering structures, such as dikes or dams, violates the 2D assumption due to the 3D topology and internal zonation, leading to potential artifacts in the inverted 2D resistivity section. The monitoring survey lines are primarily in the longitudinal direction. The resistivity of neighboring zone of different material and the topology change on the two sides of the survey line may cause 3D effects on the 2D inverted resistivity section right beneath the line. This presentation introducesforwardmodel simulationsfor planning of the survey and evaluating potential problems of 2D ERT investigation on embankments.