Dynamic Response and Energy Characterisation of High-Strength Sandstone under Progressive Cyclic Loading Based on Sustainable Mining

In the research on sustainable mining and environmental preservation, understanding the dynamic behaviour of rock formations in deep, high-stress mining environments is essential. In order to acquire the laws of rock dynamic disaster generation from mining in deep, high-stress environments, this research adopts a multistage and multi-cycle triaxial cyclic loading test to obtain the stress–strain curves and macroscopic deformation characteristics of hard sandstone under different surrounding pressures. The results show that the cumulative damage displacement of hard sandstone under cyclic loading at a certain stress level for the first 3–4 cycles is half of the total damage displacement at that cycle stage, and its peak volumetric strain will increase with the increase. The elastic energy density ratio and dissipation energy density ratio of hard sandstone under cyclic loading show a sinusoidal fluctuation trend, and the fluctuation gradually decreases with the increase in the number of cycles and the increase in the cyclic stress level. Under the cyclic loading of different surrounding pressures, the hard sandstone shows brittle damage characteristics, where the damage form is mainly shear damage with a small amount of tensile damage in low surrounding pressure and the damage form is mainly shear damage, tensile damage, and local compression damage in high surrounding pressure. The study reveals the deformation and damage law, energy evolution, and dissipation characteristics of high-strength hard sandstone. It is essential for the development of mining strategies that minimize the impact on the environment, reduce the dynamic hazards generated by mining, and maximize the efficiency of resource extraction