Correlation Analysis Between Field Electrical Resistivity Value (ERV) and Basic Geotechnical Properties (BGP)

Abstract

Past applications of electrical resistivity surveying have particularly focused on areas of subsurface ground investigations to locate boulder, bedrock, water table, etc. Traditionally, electrical resistivity surveys were directed by an expert geophysicist for data acquisition, processing and interpretation. The final outcome from the electrical resistivity technique was an anomaly image that helped describe and demarcate zones of challenging ground conditions. The anomalies highlighted uncertain geotechnical conditions that were often irregular and dependent on individual site condition, yielding a site-dependent electrical resistivity value (ERV) for the ground. This study therefore identifies co-relationships between ERV and some basic geotechnical properties (BGP) such as soil moisture content, grain size of geomaterial, density, porosity, void ratio, and Atterberg limit. Different soil samples were collected and tested under both field and laboratory conditions. Basic geotechnical properties of the samples were obtained immediately after the electrical resistivity measurements were made. It was shown that the electrical resistivity value was greatly influenced by the geotechnical properties, and thus the resistivity surveying technique is applicable to support and enhance the conventional stand-alone anomaly outcome that is traditionally used in ground investigation interpretation.