A New Calculation Method to Flexural Toppling Failure of Anti-dipped Rock Slope

By using Aydan's idea in this paper, the basal failure plane of anti-dipped rock slope will be regarded as a linear type plane. However, we consider that there is an angle (also called failure angle) between the basal failure plane and plane normal to the discontinuities, and the value of the failure angle is determined by the stress state of the rock stratums. Based on the principle of the minimum factor of safety, we suppose that the best failure angle is the one with the minimum factor of safety, and a new method to search for the best failure angle is introduced in this paper. The scope of slope failure angle will be in zero to theta(0) (the difference between face slope angle and plane normal to the discontinuities). By changing the failure angle constantly, a series of slope safety factors can be obtained through the limit equilibrium method. The minimum one is defined as the final safety factor and the failure angle corresponding to the final safety factor is the final failure angle. The linear type failure plane corresponding to the final safety factor is the basal failure plane of slope. Taking Galandrood highway slope as a numerical example, the result shows that the obtained safety factor is smaller than that obtained by Aydan's method.