Study of Stability Influencing Factors of Excavated Anti-Dip Rock Slope

A layered rock slope often forms an anti-dip state due to tectonic movement in the historical past. In the mountainous gorge area of Southwest China, the layered rock slopes are prone to toppling and deformation due to the influence of gravity and in situ stress. The stability of these slopes after excavation is very important. The failure modes and laws of anti-dip slopes are mainly affected by factors such as lithology, dip angle and rock thickness. In this paper, the excavation process of a slope was simulated by the discrete element method, and the stability after slope excavation was analysed by comparison with field monitoring data, taking the high rock slope of a hydropower station as an example. In addition, the influence of different factors on the anti-dip rock slope was analysed by setting different factors in the model. The rock thickness was set to 5, 10, 15, 20, 25, 30 and 35 metres for the same excavated model. The dip angle of the rock was set to 65, 70, 75, 80 and 85 degrees. Two major lithologies, hard rock (sandstone) and soft rock (slate), were considered in this study. The results show that the thickness and dip angle of the rock strata affected the scale of the deformation zone and the stability of the anti-dip stratified slope. However, the lithology of the anti-dip rock slope determined the failure mode of toppling failure.