Mechanical properties and stability analysis of surrounding rock of underground cavern under various stress loading paths

Abstract

Under the influence of geological tectonic movement and human engineering activities, the geological environment of rock mass is often very complex, and its stress state is also complex and constantly changing. During the excavation of underground caverns, the stress of surrounding rock will be redistributed, and its radial stress and tangential stress are constantly changing and adjusting. From this point of view, the excavation of underground chamber causes strong stress differentiation in surrounding rock, and the experimental study under simple stress path cannot fully reflect the actual state of rock engineering. In order to comprehensively understand the damage mechanism of rock under complex stress paths, this paper takes the granite of an underground powerhouse of a power plant as the research object, designs and carries out a variety of laboratory tests such as conventional triaxial test, unloading test and creep test, and obtains the deformation and failure characteristics of granite under different stress loading paths. Based on the laboratory results, it puts forward specific surrounding rock support recommendations. This study can provide more targeted supporting measures for surrounding rock under different stress states, which is of practical significance to maintain stability of surrounding rock in the factory area.