Analysis of Electrical Resistivity Characteristics of Soil-Rock Mixture under Triaxial Condition

In order to further study the electrical resistivity change characteristics of soil-rock mixture, a modified triaxial apparatus was used to conduct consolidated drained test on soil-rock mixture samples, and the changes in resistivity are measured simultaneously to obtain the electrical resistivity variation regularities during the whole consolidation and shear process of soil-rock mixture and the effect of shear strength characteristics on electrical resistivity. The stress-strain curves of soil-rock mixture and the theoretical relationship between electrical resistivity and volume strain are analyzed and established. The results show that: The electrical resistivity of soil-rock mixture in the whole consolidation and shear process is decreasing trend, and its reduction rate is first fast and then slow. Unlike conventional rocks, the stress-strain curve of soil-rock mixture has its own peculiarities. The electrical resistivity of soil-rock mixture is found to decrease with the increase of shear strength, cohesion and internal friction angle. The test confining pressure has an effect on the electrical resistivity. During the triaxial shear process, the electrical resistivity variation regularities show a rapid decrease trend with the increase of axial strain, followed by a slow decrease. Theoretical analysis shows that the change in volume strain leads to the electrical resistivity variation of soil-rock mixture. Changes in microstructure are the fundamental cause of electrical resistivity variations, which is helpful to enhance the understanding of electrical resistivity properties from the meso-level.