DefinePK

Abstract

Geo-electrical survey is an alluring tool for defining subsurface properties without upsetting soil. A systematic investigation of amalgamating geophysical and geotechnical engineering parameters for subsoil evaluation is adopted at Wattar area near Nowshera, Khyber Pakhtunkhwa, Pakistan, in order to figure the shallow subsurface. A field electrical resistivity survey of 52 m is conducted using Schlumberger configuration. Soil samples are collected from the available exposure for conducting geotechnical investigation in the laboratory. Sieve analysis, Hydrometer analysis, moisture content, Atterberg's laboratory tests (liquid and plastic limits) are performed on these soil samples. Correlation between lithology of layers and electrical resistivity is resolved by correlating the apparent resistivity values with the accepted defined values of resistivity. From the data investigation, momentous correlations have been obtained for electrical resistivity with moisture content, lithology and thickness of a layer. The field observations show that the top and bottom layer in the area is dominated by gravely sand and clayey sand respectively. The results of sieve analysis and vertical electrical sounding also proved these lithologies. The result shows a strong correlation of electrical resistivity with moisture content, lithologies and thickness of a layer. Relationship between moisture content and apparent resistivity values testify non-linear logarithmic correlation. The trend line of the curve between moisture content and apparent resistivity shows an inverse relation.