Abstract
This paper proposes a new quasi-three dimensional (3D) stability analysis method for landslides in which the quasi-3D safety factor is the weighted average of the two dimensional safety factors of longitudinal cross sections using the driving forces of longitudinal segments as the weight. The reason to use the driving forces as the weight was explained. The quasi-3D safety factors calculated by different quasi-3D stability analysis methods were compared for seven cases. The difference between the quasi-3D safety factors of the proposed method and Lambe-Whitman’s method was smaller than 2% for six cases; however, for one case, the difference was large up to 5-8%.
