Abstract
Composite ground which is improved by sand piles such as the sand compaction pile method is deformed three-dimensionally under any loading condition, approximated analysis by two-dimensional methods are performed usually. In this paper, composite grounds are analyzed by the two-dimensional FEM and the quasi-three-dimensional FEM with the special element called ‘Multi-link element’ which takes account of three-dimensional deformation between soils and piles. As a result, the two-dimensional FEM cannot express strength of composite ground well. Then various composite grounds under undrained conditon are calculated with ‘Multi-link element’. Consequently, interesting characteristics for failure pattern and stress share are obtained.
