Quantitative modeling of rock electrical resistivity under uniaxial loading and unloading

Abstract

In geotechnical engineering practice, studying the characteristics of rock electrical resistivity under different physical and mechanical environments is important for improving the accuracy of unfavorable geological condition detection. In this study, Dali marble and granite were subjected to cyclic loading and unloading at different peak pressures, and the electrical resistivity of the core samples was continuously monitored. The aim was to derive the electrical resistivity variation patterns of two rocks under cyclic loading and unloading. Then, the theoretical models of electrical resistivity for the two rocks were established through theoretical derivation, and the model equations were consistent with the experimental findings. Finally, a MATLAB program was used for nonlinear fitting of the unloading phase electrical resistivity variation patterns of the rocks to reveal the quantified pressure-electrical resistivity patterns of the two rocks with different lithologies. Based on this, well-performing rock pressure-electrical resistivity relationship models were developed with three parameters: pressure, water content and electrical resistivity. The experimental results can significantly improve the accuracy of stratigraphic state inversion and unfavorable body boundary identification by providing realistic electrical resistivity constraints for electrical resistivity tomography.