Abstract: The strength reduction finite element method, the Swedish slices method and Spencer’s generalized procedure of slices are adopted to analyze the global stability of bank slops on high-piled wharves under 108 different conditions. The results are compared to demonstrate the difference and relevance among three methods. The soil strength conditions when different slip arc modes occurred are studied with the strength reduction FEM. Meanwhile, the dependence of the lateral displacement of the feature points on the safety factor is analyzed. It was indicated that there is a difference of -1%~8% between the results of the strength reduction FEM and the Swedish slices method, though the definitions of safety factor of two methods have the same form. It also demonstrated that when the ratio of the soil strength under or behind the slope body to that of the slope is less than a certain critical value usually between 1 and 2, the slip arc will expand to a deeper position or the rear of the wharf, from which we draw a conclusion that when the safety factor comes close to the safety threshold defined by the engineering standard, there will be a drastic change in the lateral displacement. In the end, the conclusion is proved to be reasonable and efficacious by a practical project.

Key words: slope stability, the strength reduction finite element method, slice arc mode, deformation stability