| 13 Feb 2026
Modeling and Experimental Validation of Rock Resistivity Evolution During Deformation up to Failure
Abstract. Modeling the evolution of rock resistivity during deformation up to failure is important for using resistivity to evaluate rock engineering properties related to rupture. In this paper, pores are classified into three types—elastic, perpendicular plastic, and parallel plastic pores—based on the evolution of pore geometry characteristics during rock fracture and the differing contributions of pore morphology to rock conductivity. In addition, a three-porosity rock resistivity model was established by incorporating Archie’s formula. Based on the changing characteristics of the three types of rock pores under loading conditions, a pore volume evolution model under triaxial loading was derived using statistical damage theory. By combining the pore volume evolution model with the three-porosity rock resistivity model, a model for the evolution of rock resistivity during the triaxial loading rupture process was developed. Finally, the validity of the model was verified through experimental tests, and the influence of confining pressure on the model parameters was analyzed according to the test results.
(1) The authors' description of the experimental conditions lacks physical images. It is recommended to include photographs of the experimental system and samples, as well as to present and analyze the macroscopic characteristics of the samples at different loading stages. In fact, if the article aims to further explain the mechanisms underlying the observed behavior, microscopic or CT structural testing is also necessary.
(2) The representation in Figure 4 is somewhat confusing. If the pore compression is a positive value, then the axis label should indicate compression amount or compression ratio. It is suggested that the authors revise the representation in Figure 4.
(3) In the theoretical analysis and modeling, the authors considered different crack types, but in the experimental data shown in Figure 4, only the confining pressure was varied. What is the correspondence between the experiments and the theory?
(4) The article states: “During the experiment, the pore pressure was kept constant, and changes in the pore volume of the specimen were measured by recording the volume change in the pore pressure pump.” Even if water is injected around the sample, it may not fully enter the void spaces within the fractures. Therefore, measuring pore volume by recording the volume of expelled fluid may not be accurate. Conventional tests typically use mercury intrusion porosimetry, and the accuracy of the authors' experimental method is not high.
(5) Regarding the measurement of pore volume, the description in Figure 3 is unclear. It is recommended that the authors provide a detailed explanation and, if necessary, use a schematic diagram for illustration.
(6) The electrical resistivity response of fractured rock under loading differs from that of water-saturated rock. This difference is related to the wettability of the rock by water and the electrical conductivity of water.
(7) Generally, during rock loading, fractures tend to close due to compression (as also demonstrated in Figure 4 of the manuscript), and resistivity should decrease. However, in Figure 5, the resistivity increases during the initial stage. What is the reason for this? Alternatively, do the authors' testing conditions differ from conventional testing methods?
(8) The triaxial resistivity evolution model established in this paper is based on statistical results. What is its significance? Given that different rock types and loading conditions would require new statistical analyses, the authors are advised to provide a detailed analysis of the physical meaning underlying the statistical model.
(9) The overall workload of this paper appears relatively low, making it more akin to a short communication. It is recommended to increase the depth of data analysis or to include control experiments.
(10) The analysis of the rock conductivity mechanism lacks support from experimental or numerical simulation data. It is difficult to understand why the authors concluded that “This model effectively captures the morphological and volumetric changes in pores and fractures during the triaxial loading rupture process, as well as the conductive mechanisms of saturated rock.”
(11) There is a lack of comparison with conclusions from previous experimental studies, and the novelty of the article is not clearly articulated.
(12) There are too many outdated references.