Soft rock rheological similarity criterion under thermal-mechanical effects—a research and its application

Abstract

Abstract The similarity criterion of soft rock in both the linear elastic deformation range and the rheological process are systematically studied in this paper by using the equation derivation method and the dimensional analysis method under the effects of temperature and pressure. A brief analysis is performed and COMSOL is used to verify the deduced similarity criterion numerically. A shale-like material with paraffin wax as the binder and river sand as the main aggregate is then prepared by following the similarity criterion, including compressive strength, tensile strength, elastic modulus, Poisson’s ratio, and thermal conductivity. The mechanical parameters and thermal conductivity of the fabricated shale-like material are measured, and the result shows that the shale-like material has a high similarity with the shale prototype material by comparing the experimental data with the calculated data based on the similarity criterion. This reveals the significance of the similarity criterion for developing model experiments. Thus, this research has enriched the rheological similarity principle system of soft rock and has an important practical value in deep soft rock excavation and support engineering.