Abstract: Current studies of flexural toppling failure rarely involve earthquake loading,and the influence laws of earthquake load on the stability of anaclinal layered rock slopes subjected to flexural toppling is unclear.In order to solve the above problems,we present a limit equilibrium method to evaluate the stability of anaclinal layered rock slopes subjected to flexural toppling under earthquake load.We consider that once the overall failure of a slope occurred,the stress of the slope reached the limit equilibrium state,i.e.,the residual sliding force (toppling force) of slope toe calculated along the failure surface was zero.Based on the idea of static equivalent substitution,the calculation formula of the non-dimensional height of the point of application of normal force was derived.The stable zone,potential failure zone and the failure modes of potential failed strata were determined via strict mechanical derivation,and the residual sliding force (toppling force) of slope toe was obtained with step by step analysis method.The calculation results for a slate slope in South Anhui as an engineering example demonstrate that the slope failure plane and the safety factor of the stability of the slope are credible.Through the sensitivity analysis of seismic coefficient,we found that with the increase of seismic coefficient,the residual sliding force of slope toe increase while the safety factor of the stability of the slope decrease,and consequently,the slope is subjected to shallow damage and becomes more unstable.

Key words: slope engineering, flexural toppling, earthquake load, stability analysis, limit equilibrium method, failure plane, residual sliding force