Effects of Slope Angle on Toppling Deformation of Anti-Dip Layered Rock Slopes: A Centrifuge Study

To reveal the impact of slope angle change on toppling deformation, this paper takes the dam toppling deformation of Gushui Hydropower Station based at Lancang River as an example, based on which three groups of models with different slope angles are conceptualized and designed. Through the centrifuge test, the evolution of toppling deformation of a counter-tilt layered slope under different slope angles was simulated. The research results show that: (1) The steeper the slope angle, the shorter the cumulative time required for such deformation is, the larger the toppling deformation will be, and it is more likely that multi-stage fracture zones will occur during the toppling process. (2) The toppling deformation process can be summarized as four stages. (3) The toppling deformation mainly occurs above the datum surface of the toppling fracture; the angle between the datum surface and the normal of the layer is between 12° to 16°. This value shall not change as the slope angle changes. (4) The lesser the slope angle is, the more likely the toppling deformed slope will be experience overall slipping instability. while the steeper the slope angle is, the greater the possibility of collapse after the rock mass falls.