Abstract
Because the traditional limit equilibrium method of 3D stability analysis assumes moving body of a landslide as rigid mass, it ignores horizontal ground pressure exerted on a slip surface. However, frictional resistance exerted by horizontal earth pressure on the flanks of a slide is believed to be greatly influential to 3D stability analysis, hence the authors examined to include horizontal earth pressure in the limit equilibrium method of the analysis. Furthermore, the authors built equations reflecting this alternative method applied in the Janbu methods of the two-dimensional stability analysis as well as of the three-dimensional simplified analysis. In this paper, calculation results of the equations applied to data samples from actual landslide areas are presented in detail. Safety factor was 1 to 4% higher with the two-dimensional analysis and 3 to 16% higher with the three-dimensional analysis both compared to the traditional methods.
