Resistivity Response of Thermally Treated Granite During the Compression Test

To determine the stress and damage state of rock mass is important for many geotechnical engineering. To study the feasibility of resistivity measurement in characterizing the damage and stress state, the resistivity measurement, uniaxial compression test, and incremental loading-unloading compression test were carried out on granite samples with different porosities (induced by different treatment temperatures). Results show that the resistivity is very sensitive to thermal damage and mechanical damage during compression. The evolution of resistivity can not only quantify thermal damage but also clearly indicate the critical stress (crack closure stress and crack damage stress) and damage stage during compression. In addition, the resistivity evolution was quite different in the pore closure stage, elastic deformation stage, and unstable cracking stage during the loading-unloading process, which is useful in field stress and damage state identification for field monitoring. The conductive mechanism variation during compression was discussed using the Archie equation considering crack volume strain evolution during the mechanical damage process. Overall, the resistivity measurement holds great potential in geotechnical engineering for field monitoring.