Slope Stability Analysis Based on Experimental Design

In this paper, the authors propose an analytical model for the prediction of the slope safety factor as a function of basic geometrical parameters (slope height H and slope angle β) and soil factors (bulk density γ, cohesion c, angle of internal friction φ, and pore water pressure coefficient ru). Research was performed by applying the statistical technique of experimental design, for which the input data were provided by stability analyses of different homogeneous slopes with a circular slip surface using the Spencer limit equilibrium method. The proposed model represents a nonlinear equation of a simpler form and higher prediction accuracy than those of the existing mathematical expressions, with predominant linear effect of the individual factors and significant influence of the two-factor interactions. Linear terms in a derived equation indicate a positive effect of c or φ and a negative effect of H, β, γ, or ru on slope stability. Because of two-factor interactions, the effect of c is highly dependent on H, β, γ, and φ, whereas the influence of φ is predetermined by the values of β and ru.