Predicting sandy-clayey soil properties using electrical resistivity testing

Non-destructive tests are economical and easy-to-use techniques to determine different soil properties, which speed up the determination of sub-surface characteristics. They include ground-penetrating radar, seismographs, shear wave velocity and electrical resistivity testing. The latter is gaining worldwide popularity for determining sub-surface geology in geotechnical engineering as it does not require extensive testing. The aim of the study reported in this paper was to develop empirical correlations of electrical resistivity testing with different soil parameters by performing extensive conventional laboratory tests. These correlations would help in computing the required soil parameters by performing solely electrical resistivity testing, saving the time and effort required by conventional tests. The correlations developed included the relationship of resistivity values of soil with the drained angle of internal friction, effective cohesion, Atterberg's limits, maximum dry density, optimum moisture content and bearing capacity of a variety of shallow foundations. The regression coefficients obtained ensured the development of quite a good correlation, such that the result of electrical resistivity testing can be used for reasonably accurate determination of sandy-clayey soil properties.