The effect of soil stiffness on the undrained bearing capacity of a footing on a layered clay deposit

The bearing capacity of footings on layered clays has been studied previously, but with the clays assumed as rigid plastic materials. In this study a circular footing was penetrated into a stiff-over-soft clay deposit in a centrifuge. It was found that, within a small displacement range (i.e. ~ 15% of footing diameter), the footing capacity did not reach its limit, as predicted by the rigid plastic analysis. Both small strain and large penetration finite element (FE) analyses were performed. The centrifuge test data were compared with the FE results from small strain and large penetration analyses. It was observed that the footing capacity on the layered clay surface is dependent on the soil stiffness.