Ground condition evaluation based on electrical resistivity survey and basic geotechnical properties of Jahangirnagar University Model Town area, Savar, Dhaka, Bangladesh

Abstract

 The electrical resistivity methods are widely used for identifying the complex subsurface lithology and delineating the characteristics of the aquifer. A field data acquisition system has been performed to enable an electrical image to be produced for a site located at Jahangirnagar Model town adjacent to Islamnagar Bazar area, Savar, Dhaka, Bangladesh. A 100 m electrical sounding image line have been constructed following the Wenner array with 4 m electrode spacing revealed the shallow subsurface lithological variations. A borehole location was selected along the image line and subsoil samples were collected every 1.52 m (5 ft) intervals using a light cable percussion drilling technique. Some geotechnical parameters such as moisture content, specific gravity, grain size distribution, liquid limit, plastic limit, plasticity index were measured in the laboratory. The obtained basic engineering properties are compared with the electrical resistivity of the soil in order to evaluate the shallow subsurface geology of the study area. It is found that the electrical resistivity significantly influenced by the variation of basic soil properties. The geotechnical results also confirmed the significance of the recorded image constructed by the measured electrical resistivity values.