3D Effect Analysis of Geometrically Complicated High-Filled Slope Stability

Strength reduction method is frequently used to evaluate the slope stability in 2D FEM. Stability factors of embankment's cross section at the gully bottom and of the whole embankment are obtained by 2D and 3D FEM respectively in this study. It is found that the stability factor obtained by 2D analysis is smaller than that of 3D. The instable surface of the embankment obtained by 3D technique is approximately spherical or elliptical, obviously different in shape from the cylindrical surface plotted by 2D, which shows significant 3D effect in the geometrically complicated high-filled embankment at complicated terrain. Further 3D FEM to evaluate the stability of the embankment with varied gully-bank gradients demonstrates that the stability of the embankment decreases with the reduction of gully-bank gradients. Hence, 3D effect should be taken into account in the geometrically complicated high-filled embankment, and the results gained by 2D FEM should be modified.