Laboratory Studies Using Electrical Resistivity Tomography and Fiber Optic Techniques to Detect Seepage Zones in River Embankments

Abstract

We present the results of laboratory experiments on a down-scaled river levee constructed with clayey material collected from a river embankment where a permanent resistivity instrument has operated since 2015. To create potential seepages through the levee, two zones (5 × 4 cm and 10 × 2 cm) were filled with sand during the levee construction. Electrical resistivity tomography (ERT) technique and Fiber Bragg Grating (FBG) technology were used to study time-lapse variations due to seepage. The ERT profile was spread on the levee crest and the Wenner array with unit electrode spacing a = 3 cm was used. Six organic modified ceramics (ORMOCER) coated 250 μm-diameter fibers were deployed in different parts of the levee. Time-lapse measurements were performed for both techniques from the beginning of each experiment when water was added to the river side until the water was continuously exiting from the seepage zones. The results showed that ERT images could detect seepages from the early stages. Although with a short delay compared to ERT, fiber optic sensors also showed their ability to detect water infiltrations by measuring temperature changes. Both technologies being successful, a discussion about respective peculiarities and pros and cons is proposed to suggest some criteria in choosing the proper technique according to the specific needs.

Towards a decentralized solution for sewer leakage detection – a review

“…Although the authors were able to successfully monitor the leakage from the tank, it is stated that results are significantly influenced with metal presence. Within a more recent study, Hojat et al (2021) demonstrated the seepage from a river levee in a laboratory experiment implemented with ERT during two stages of leakage (Figure 4) and concluded that ERT is capable to detect the seepage in early stages.…”

Application of Electrical Tomography Imaging Using Machine Learning Methods for the Monitoring of Flood Embankments Leaks

“…A possible regularisation method is an elastic net, defined as a linear mixture of a Selection Operator (LASSO), Least Absolute Shrinkage and ridge regression, which is called Tikhonov regularisation [52,53]. Instead of the solution of classical task (5), which is connected with an estimation of unknown parameters in the logistic regression model, we optimise the objective function (6) whilst taking the penalty into account. In order to do this, we need to solve the following equation:…”

“…This solution determines changes in the physical parameters of the tested object (resistivity). Finally, electrical resistivity tomography (ERT) [4][5][6] is used to study shafts. The resistivity tomography method consists of placing the measuring electrodes along the profile line at equal distances.…”

Integrated high-resolution electrical tomography and drilling cascading investigation of earth-rock dam leakage in a siltstone region: A case study of the Maoshan Reservoir, China

“…These methods are widely utilized due to their rapid speed and cost effectiveness [9]. They have been extensively applied in the leakage investigations and analyses of various engineering structures, such as dams, levees, and tailings dams [10][11][12][13][14]. Additionally, they have been applied in geological environmental analyses of features, such as karst, culverts, and other geological structures [15][16][17][18].…”