Cyclic Drying–Wetting Effect on Shear Behaviors of Red Sandstone Fracture

Excerpt

To maintain sustainable development in society and the economy, large water projects have been built or being built in the mountainous areas of P.R. China, such as the Three Gorges Reservoir (completed) and the Middle-Yunnan Water Diversion Project (under construction). Changes in hydrogeological conditions may cause instability in the reservoir areas, including landslides, rock avalanches, debris flows, ground fissures, and ground subsidence (Li et al. 2019; Tang et al. 2019a, b). From construction to operation, periodic water-level fluctuation can affect the deformation and stability of rock slopes. Based on a purely mechanical perspective, the water–rock interaction induced by the fluctuation of reservoir water level may be an adverse factor causing rock landslides. In terms of the physical impact of such water–rock interaction, the rock masses in the reservoir area are subjected to cyclic drying–wetting due to the periodic changes in groundwater levels. In practice, the deterioration in the physical and mechanical properties of the rock masses is usually related to water (Wong et al. 2016); however, the influence of cyclic drying–wetting on the issue is still poorly understood (Zhao et al. 2017a). As such, a better understanding of the physical and mechanical properties of rock subjected to cyclic drying–wetting is an ongoing research issue, particularly to analyze the stability of rock slopes located in reservoir areas in P.R. China. In addition, wave propagation in rock masses is influenced by the drying–wetting process, and studying the interaction of stress waves and rock fractures is crucial for evaluating the stability of rock engineering structures, such as tunnels, foundations, and rock slopes under dynamic loading (Li et al. 2014a, b; Chen et al. 2015; Li et al. 2015, 2017). …