Experimental study on the mechanical properties and energy evolution of hard rock during water immersion

Water is an important factor affecting rock properties. In this paper, through uniaxial compression experiments on marble, granite, and sandstone with different water immersion times, the difference in the failure mechanism and time effect of three types of hard rock during water immersion condition were studied. The results indicate that different rock components have different sensitivities to water immersion. Under loading, with increasing water immersion time, the failure mode of marble and granite gradually transitions from tensile failure to shear failure, while the failure mode of sandstone transitions from tensile-shear composite failure to tensile-dominated failure. For marble, water reduces the probability of rockburst to some extent, but it has little influence on the intensity. The accumulated strain energy of granite decreases slightly, which may limit the intensity of potential rockburst. The strain energy storage capacity of sandstone significantly reduces, resulting in a significant decrease in the potential failure intensity. Most studies are limited to the mechanical properties of a single rock type before and after immersion, but difference analysis and comparison of the mechanical properties and energy evolution of different hard rock types after different periods of water immersion are rarely reported. The research results are of theoretical value to the in-depth study of the mechanism of water–rock interaction and have practical guiding significance for the practice of controlling rockburst with water treatments in engineering applications.