Correlation of Electrical Resistivity Test with the Geotechnical Parameters of Sandy Soil

Abstract

Non-destructive tests (NDTs) are the most economical and easy to use techniques to determine different soil properties. They expedite the process of determining sub-surface characteristics. These include Ground Penetrating Radars (GPRs), Seismographs, Shear Wave Velocity (SWV) and Electrical Resistivity Test (ERT) etc. ERT is nowadays getting worldwide popularity for determining the sub-surface geology in geotechnical engineering, as it does not require extensive testing. This research aimed at developing empirical correlations of ERT with different soil parameters by performing extensive conventional laboratory tests in order to get all the required soil parameters by just performing ERT in the future, which otherwise require great time and effort to be determined by the conventional laboratory tests. The developed correlations include relationship of resistivity value obtained in the field with the internal friction angle (r² = 0.964), cohesion (r² = 0.946) and the bearing capacity of shallow foundation (r² = 0.90) for depth to width ratios of 0.5 and 1.0 respectively. The regression coefficients obtained ensured the development of quite good correlation for the sandy-clayey soil.