Study of failure patterns of foundation under combined loading

Based on the limit equilibrium method, the failure patterns of undrained saturated foundation under combined loading are investigated by virtue of the finite element software ABAQUS in detail. The conclusion shows that the vertical loading V can control the extent of depth of the sliding surface, the horizontal loading H and the moment loading M make the failure envelope of foundation asymmetry; the forward-tilted scoop failure mode and the backward-tilted scoop failure mode, which are given in this paper, can interpret properly the asymmetry of failure envelope in H-M loading space. Finally, the relationship between the different failure patterns and the loading compound modes in H-M loading space is given; moreover, the discrimination equation of appearance of maximum moment Mmax is given.