Seepage identification of Sidoarjo mud embankment via 2D resistivity and self-potential methods

Assessment of embankment stability is one of the ways to discover the embankment condition. Several factors can affect the strength of the embankment body including seepage, leakage, deformation (vertical and horizontal), and overtopping. Hence, identification of seepage in the subsurface of the embankment is important to provide early information about the threat of embankment failures. Sidoarjo mud (LUSI) embankment has been collapsed several times since it built in 2006. Most of the failures are mainly caused by the existing water seepage in the subsurface of the embankment. To identify the seepage pathways of the embankment body, two non-destructive geo-electricity methods were applied in the LUSI embankment. Direct current resistivity (DCR) and self-potential (SP) methods were carried out to reconstruct subsurface conditions at lines P76-P79. Therefore, seepage interpretation was conducted to identify the presence of water flows through the embankment body. 2D tomography of resistivity data revealed the indication of water seepage in some measurement areas. This information was strengthened by the numerical interpretation of self-potential data, recognizing water seepage through the embankment body in each line.