Stability analysis of a ground-sheet pile system on the soft ground

In this paper, the stability of a ground-sheet pile system was quantitatively evaluated using the elasto-plastic finite element method. First, on the case in which plastic deformation was generated in the outside of sheet pile, the sensitivity analyses about the effect of the FEM analysis conditions on safety factor were carried out. The analytical results of FEM were compared with the conventional slip circle methods of slices. As the result, the safety factor of FEM was greatly changed with the finite element mesh size and the friction assumption between the sheet pile and the ground. Second, on the case in which the slip surface passes the inside of sheet pile since the bending rigidity of sheet pile is relatively smaller than the rigidity of the ground, the applicability of FEM was examined. It was proven that the bending rigidity of sheet pile greatly affected the stability of this system and the elastic modulus of the ground had to be appropriately given in order to evaluate the safety factor quantitatively.