To investigate a problem of bearing capacity of a natural clay, a soil-water coupled finite deformation analysis is performed with the elasto-plastic constitutive model that describes the effect of the decay of soil skeleton structure due to plastic deformation. From the computational results the findings are as follows: (1) In a structured clay soil, a load peak phenomenon appears, accompanied by a local circular slip field. (2) In a clay soil possessing anisotropy, this area of failure is more confined, and the peak is lower.