Experimental Study on the Mechanical Properties of Deep Granite under Gradient-Confining Pressure

In deep layers, the complex geological environment is characterized by high temperature and high stress which causes marked differences in the mechanical properties of granite compared to those of granite in shallow areas. To investigate the mechanical properties of deep granite, this paper utilizes conventional triaxial compression tests to determine the various mechanical properties and failure modes of deep granite under different confining pressures. The findings indicate that the elastic modulus, Poisson's ratio, and peak strength of deep granite display greater dispersion than those of shallow granite under the influence of confining pressure. Based on the stress-strain curve, various characteristic stresses of deep granite under different confining pressures are calculated, and a distinct exponential function relationship exists between the characteristic stresses and the confining pressure. Furthermore, the finite element numerical simulation software Abaqus is employed to simulate the conventional triaxial compression of granite under different confining pressures, thereby revealing the stress and deformation evolution process of granite during the compression process. This research unveils the mechanical properties of deep granite under gradient-confining pressure, which can offer crucial theoretical evidence and data to support engineering applications in relevant fields.