An Analytical Solution for the Stability Evaluation of Anti-Dip Layered Rock Slopes Under Water-Level Fluctuations in Reservoirs

Significant fluctuations in reservoir water levels occur seasonally during the flood period, adversely affecting the stability of bank slopes. In this paper, a modified mechanical model for the flexural toppling of anti-dip rock slopes under water level fluctuations is established, and an actual deflection equation for rock slabs is derived. The critical length for the flexural toppling failure of rock slabs is calculated, which can be used to evaluate slope stability. Multiple linear regression analysis reveals the relative degree of the influence of each parameter (such as rock slab thickness, rock layer dip angle, water level height, etc.) on the critical length. The results indicate that rock slab thickness plays a controlling role in slope stability. The failure mechanisms of the slope under the influence of water level fluctuations are revealed through fluid–solid coupling numerical simulations. The results indicate that the rise in water level reduces the strength of the rock mass in the submerged zone and generates significant water pressure on the rock mass at the slope toe, leading to its cracking. A rapid drop in water level generates seepage forces detrimental to slope stability and carries away fractured rock particles at the slope toe, ultimately causing slope failure. Finally, the reliability and applicability of the proposed method are validated through numerical simulations, case studies, and comparisons with existing analytical solutions.