INFLUENCE OF BEDDING EFFECT ON MECHANICAL CHARACTERISTICS AND ENERGY DISSIPATION IN TRIAXIAL LOADING PROCESS OF BLACK SHALE

In order to explore the influence of black shale bedding on its mechanical characteristics and energy dissipation process,this paper uses the black shale of Longmaxi Formation as the research object,obtains the characteristic stresses,volume strain and crack strain under different confining pressures and bedding dip angles with indoor conventional triaxial compression tests and analyses the crack strain and energy evolution mechanism according to the principle of energy balance. The research shows that the characteristic stress and characteristic stress ratio show a "V"-shaped trend with the increase of the bedding surface inclination under the same confining pressure value. As the confining pressure increases,the energy density of the dissipated energy mutation point gradually increases. The dissipation ratio presents a "V"-shaped trend with the increase of axial crack strain. Before and after the failure of the rock samples,there is a certain conversion relationship between elastic strain energy and dissipation energy with the bedding. The research results provide a reference for further exploring the influence of black shale bedding effects on its mechanical characteristics and energy evolution mechanism.