Effect of Pore-Water Salinity on the Electrical Resistivity of Partially Saturated Compacted Clay Liners

Abstract

The aim of this paper is to investigate the effect of pore-water salinity on the electrical resistivity (ER) of different compacted clay liners (CCLs) in terms of its mineralogical composition. For this purpose, an experimental programme was conducted where ERs of different kaolin-dominant CCL specimens, reconstituted using water having different concentrations of NaCl (0 M, 0.5 M, and 1.0 M), were measured. The kaolin-dominant CCL specimens tested in this study include pure kaolin, three different kaolin-bentonite mixtures, and three different kaolin-sand mixtures. The experimental results show that the ERs of CCL specimens decrease as the salt concentrations in pore water, moisture content, and dry density increase. At constant density and moisture content, the test results also indicate that increasing the sand content in kaolin-dominant CCL specimens increases its ER regardless of the water salinity level. This behaviour could be attributed to the lower surface conduction of sand compared to kaolin. However, at constant density and moisture content, increasing the bentonite content in kaolin-dominant CCL specimens decreases its ER in the distilled water environment as surface conduction of bentonite is higher compared to that of kaolin. On the contrary, in saltwater environments, ER increases as the bentonite content increases. This behaviour could be explained in terms of the expected aggregated microstructure of bentonite in the saltwater environment that could reduce the number and area of interparticle contacts, and consequently, increase the ER of CCL specimens.

An unconventional method for calculating porosity of marine clay deposits using the 2D resistivity method

“…2018; Lu et al . 2019). The lowered values do not accurately represent F i values, which should not have any influence on surface conduction; therefore, the latter is designated as the apparent resistivity formation factor, F a , as shown in equation (3) (Glover 2016; Yue 2019): …”

“…The presence of the fine grains lowers ρ o values and thus also ρo ρw values, as fine grains induce surface conduction that alters the electricity flow (e.g. Al Rashid et al 2018;Lu et al 2019). The lowered ρo ρw values do not accurately represent F i values, which should not have any influence on surface conduction; therefore, the latter is designated as the apparent resistivity formation factor, F a , as shown in equation 3) (Glover 2016; Yue 2019:…”

Effect of Temperature and Water Salinity on Electrical Surface Conduction of Clay Particles

“…Temperature has a significant impact on the physico-chemical properties of soils. Electrical conductivity (EC) is one of the properties of soils which is influenced by temperature [1,2], as well as pore water salinity [3][4][5][6], soil mineralogy [7], moisture content [8,9], porosity [10,11], and soil anisotropy [12,13], to name a few. The advantage of using EC in geotechnical engineering has been widely discussed, and this approach is favoured, particularly in the investigation of subsurface ground [14][15][16][17].…”

Identification of Breaches in a Regional Confining Unit Using Electrical Resistivity Methods in Southwestern Tennessee, USA

“…The resistivity of the soil decreases with increasing soil water saturation and pore-fluid salinity. However, the salinity of the pore-fluid affects soil resistivity more than the saturation [20][21][22][23]. Previous studies have highlighted the significance of considering factors such as soil saturation, pore-fluid salinity, and landscape characteristics when analyzing ER data [24][25][26][27][28][29].…”