Study on the energy characteristics of rocks under cyclic loading and unloading

The deep-buried rock masses influenced by prolonged geological processes have accumulated vast amounts of energy. This stored energy is released due to disturbances in the external environment, a series of geological disasters is triggered. In this study, triaxial cyclic loading tests were carried out on sandstone and granite at different strain amplitudes to investigate the variation of rock internal energy. Stress–strain curves were recorded under various amplitudes. The calculation model of dissipated energy, elastic energy and plastic energy was established. Energy variations are analyzed to explore the dissipation mechanism of internal energy in rocks. The results show that with the increase of strain ratio, the dissipated energy, elastic energy and plastic energy all increase. When the strain ratio reaches a certain range, the slope of energy increase exhibits a sudden change. The study of the rock failure mechanism from the perspective of energy offers practical and guiding significance for the safety assessment and stability prediction of various geological disasters.