THERMAL-HYDRAULIC-MECHANICAL COUPLING MECHANICAL BEHAVIOR AND ACOUSTIC EMISSION CHARACTERISTICS OF DEEP SANDSTONE

Based on the deep in situ mining environments with "three high", a triaxial compression experiment of water-saturated sandstone under the conditions of 150 degrees C, 110 MPa confining stress and 105 MPa pore water stress was carried out. The results show that the creep deformation stage produces a surge in acoustic emission energy when the radial deformation of sandstone changes from expansion to rapid compression, and the sandstone is sheared by a single crack when it is damaged. From deformation monitoring and acoustic emission energy analysis, the thermal-hydraulic-mechanical (THM) coupling environment will cause irreversible changes to the internal stress distribution, pore structure and mineral framework of sandstone. In the THM coupling experiment, the irreversible impact of the rock sample due to the long-term simulation of the "three high" environment and the difference caused by the impact on the final experimental results should be considered.