Abstract
Summary Recently, the use of electrical prospecting with high spatial density of electrodes has increased and is being applied to underground investigations for mineral exploration and other civil engineering purposes. In order to characterize rock mass using the resistivity distribution of ground, which is obtained from these investigations, it is important to understand the relationship between the electrical resistivity and physical properties of rocks. In this paper, the resistivity of various types of rocks is measured to elucidate the effect of the physical properties of rock on resistivity. The resistivity of rocks has a tendency to decrease with increasing porosity. However, the resistivity does not always correspond to porosity even in the same type of rock, because of different mineral compositions and pore geometries. The resistivity of the rocks increases with the increase in the pore fluid resistivity, regardless of the rock types. However, between 20 and 100 ohm-m, which is the available groundwater resistivity in rock masses, the resistivity of pore fluids had a little effect on the rock resistivity. The resistivity of the rocks decreases with increasing water saturation up to a certain point, beyond which the degree of this drop becomes insignificant. Further, the resistivity of unsaturated rocks exponentially increases with the decrease in the water saturation of 20% or less.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call