Application of the GPR and ERT methods for non-invasive examination of a flood dike

Abstract

As part of the NAWA-EMMAT project, geophysical surveys were carried out on selected sites in Poland, i.e. on the flood dike and in the surrounding of the concrete water dam. The goal of the surveys was the non- invasive detection of loose zones in the flood dike and fractured zones located in the subsoil of the water dam. Terrain geophysical measurements were conducted with the use of electrical and electromagnetic methods as well as applying seismic methods. Due to the limitations of the length of this paper, only selected results recorded on the flood dike using selected geophysical methods, i.e. electrical resistivity tomography (ERT) and ground penetrating radar (GPR) are presented. The presence of several higher hydraulic permeability zones in the dike was suggested by the results of the ERT method. The GPR method allowed, due to its high resolution, to identify small leakage zones in the body of the dike. An attempt at a quantitative interpretation of the geophysical data was made; for this purpose, the synthetic results obtained from numerical modelling of electrical and electromagnetic fields were applied. For proper construction of numerical models and further interpretation, the results of geotechnical sounding, geological drilling and the results of petrophysical measurements were also used.

Application of Complex Geophysical Methods for the Detection of Unconsolidated Zones in Flood Dikes

“…In general, there are many geophysical methods that may be applied for the examination of a flood dike and its subsoil; mostly electrical and electromagnetic methods were applied for this purpose, i.e., the standard (i.e., short-offset reflection profiling) ground penetrating radar (GPR) method, which is typically used as a profiling method [2][3][4], or 2 of 24 non-standard GPR surveys [5][6][7][8][9][10][11][12][13], in which the different antenna orientations can be used to provide a more reliable picture of the internal structure of the levee or can to provide the GPR attributes to pick weak zones in the levees. One of the most used methods, in this case, is also electrical resistivity tomography (ERT), also called the resistivity imaging (RI).…”

“…1 (Figure 1C-over leakages no. III, IV, and V); the selected results, obtained at this stage, were presented in various scientific conferences [6,9].…”

“…1 (Figure 1C-over leakages no. I and II); the results of numerical modelling, carried out for the GPR and ERT methods, were presented at a scientific conference [9].…”

Application of Combined Geophysical Methods for the Examination of a Water Dam Subsoil

“…One of the most used methods in this case is also electrical resistivity tomography (ERT) called also the resistivity imaging (RI). In most cases 2D ERT technique was applied [12,13]. It is worth mentioning, the prior mentioned methods are commonly applied techniques and the most effective to study the In the next stage the literature study was performed.…”

Geophysical and Uav-Based Observations Over a Flood Defense Structure: Application to the Polder2c’s Experimental Dike

“…In this context, geophysical methods such as ERT, GPR, Multichannel Analysis of Surface Waves (MASW), seismic refraction, electromagnetic induction (EMI) or Self Potentials (SP) has gained more and more importance to characterize dikes (Fargier et al, 2014;Tomecka-Suchoń, 2019;Niederleithinger et al, 2012;Rahimi et al, 2018;Bolève et al, 2012). Amongst these methods, ERT and GPR are useful and complementary tools, easy to carried out on the field for dike assessment (Golebiowski, Tomislaw et al, 2020). Most of the cases, they are performed both on crest and at toe of dikes and less often transversely to the structures.…”