A review of the research on physical and mechanical properties and constitutive model of rock under THMC multi-field coupling

The study of multi-field coupling of rocks has been carried out for decades, including the effects of single physical field, two-field coupling, and three-field coupling of rocks. However, the occurrence environment of rock mass in deep mining of mineral resources and underground space development is very complex. Thermal–hydrological–mechanical–chemical (THMC) multi-field coupling effect will occur in rock mass under high temperature, high osmotic pressure, high stress, and complex hydrochemical environment. The multi-field coupling of rocks is not the simple superposition of multiple physical fields, but the mutual influence and action of each physical field. The research on fracture evolution, deformation mechanics mechanism, mechanical constitutive and coupling model construction was comprehensively analyzed. Based on the analysis of rock strength theory, the development of a rock multi-field coupling constitutive model and a rock creep constitutive model were obtained. There are some differences in the research focus of multi-field coupling of rocks for different industries. The multi-field coupling of rocks not only involves the development of mineral resources, oil and gas fields, geothermal resources and other resources and energy fields, but also water conservancy and hydropower engineering, alpine engineering, underground engineering, underground nuclear waste disposal, and deep buried energy storage. Under the action of high stress, seepage, high temperature and chemical action, not only will the coupling effect occur, but the physical and mechanical properties of rock itself will be affected. It is of great practical significance to analyze and study the mechanical properties of rocks under the action of multi-field coupling for preventing accidents and ensuring engineering safety. Finally, the key and difficult points of rock multi field coupling research and the direction of future research were discussed, which provides a reference for engineering practice and related problems.