Investigation of Geotechnical Factors Affecting Electrical Resistivity of Soil

Abstract

The use of electrical resistivity (ER) in subsurface investigation has increased in recent years. Resistivity imaging (RI) is a non-destructive method and provides a continuous image of the subsurface. However, only, qualitative evaluation of the subsurface can be obtained from RI. The correlations between ER results and geotechnical engineering properties of soils have become important for site investigation using this method. The primary objective of the current study was to determine the geotechnical parameters affecting electrical resistivity of compacted clays. Understanding the influential factors will be helpful in determining the correlations between RI results and geotechnical properties of soil. The geotechnical properties of soil obtained from laboratory tests such as oven dry test and standard proctor compaction test. The effects of moisture content, unit weight, and degree of saturation on soil resistivity were investigated. Resistivity tests were conducted on the actual field on composite soil at varying moisture contents, temperature, and unit weights. The field results reveal that a higher degree of saturation results in a lower electrical resistivity. The electrical resistivity increases gradually with increasing dry unit weight of soil.