Research Progress on Shear Mechanical Properties of Deep High−temperature and High−pressure Rock Mass

As a clean and renewable dominant resource for power generation in the geothermal field, deep dry hot rock is a premium−quality geothermal rock mass with high−temperature and high−pressure, low porosity and low permeability, it is necessary to carry out seepage−increasing mining through thermal storage water fracturing technology. In the process of hydraulic fracturing and reservoir construction, low−pressure water injection induces shear slip of fracture network or primary fracture, which promotes the fracture to realize dislocation support under its rough surface. It is one of the main technical methods of thermal reservoir permeability enhancement. Its theoretical basis is the shear mechanical properties of high−temperature and high−pressure rock mass. In order to spectify the research progress of shear mechanical behavior of high−temperature and high−pressure rock mass, based on the conventional shear mechanics theory and laboratory test methods, we generalize the research status of shear theoretical model of high temperature and pressure rock mass, introduce the progress of shear test equipment of high temperature and pressure rock mass, comprehensively review the shear physical and mechanical propertie, deformation and failure laws of high−temperature and high−pressure rock mass, summarize and discusse the influence mechanism of thermal stress and thermal shock effect on rock microstructure.