A study on altered granite meso-damage mechanisms due to water invasion-water loss cycles

Water-level variations of tailings ponds can result in slope rocks being in a state of water invasion-water loss which can lead to irreversible damage to the rock meso-structure. This study combines qualitative analysis and quantitative characterization to investigate rock meso-structure damage due to water invasion-water loss cycles by analyzing the variations of rock meso-structures using a scanning electron microscope (SEM). Results from this analysis identified four stages in the variations of rock meso-structure under the action of water invasion-water loss cycles: overall homogeneity and compactness stage, primary pore expansion stage, porous flocculation stage, and a pore and fracture development stage. According to the fractal dimension in SEM test results, we can define rock meso-damage variable D_f (which attained a maximum of 33.57%), thus realizing the quantitative characterization of rock damage under the action of water invasion-water loss cycles. After demonstrating that the evolutionary relationship between fractal dimension/damage variable and cycle number conforms to exponential function change, we also explored rock meso-damage mechanisms under the action of water invasion-water loss cycles.