Investigating the effect of NaCl content of pore water on the electrical resistivity of soil samples

Geophysical laboratory measurements are important to provide data base for better interpretation of field surveys as well as developing new applications of these methods. The purpose of this research is to study the effect of NaCl content of pore water on the electrical resistivity of saturated soil samples. To do this, a cylindrical cell was constructed to contain soil and water samples for resistivity measurements. The cell was calibrated using distilled water samples of known resistivities. In the first step of our measurements, water samples of different NaCl content were prepared and their resistivity values were measured. Then, laboratory measurements of electrical resistivity were carried out on saturated sand samples of different grading. The results of all the tests showed that as the salinity of the pore water is increased, the resistivity of the soil samples decreases. Moreover, it was observed that using samples of equal NaCl content, the coarser the soil, the higher resistivity is measured.

Keywords:

electrical resistivity , laboratory measurements , NaCl content , saturated soil