Abstract: A large number of cyclic UU triaxial tests of the soft clay were conducted,showing that the failure of the soft clay with static and cyclic loads obeyed Mises criterion by analysis of test results.The cyclic strength of soil element in general stress states could be determined according to Mises criterion and cyclic triaxial test results.A method evaluating cyclic bearing capacity of foundation based on cyclic strength of soil element was further suggested,with consideration of effect of different cyclic strengths of element in different static stresses on the cyclic bearing capacity.The cyclic bearing capacity of a single bucket foundation was then evaluated using it.Results show that the vertical and horizontal cyclic failure loads depended on static loads.When the vertical static load was 0.3 times of the static bearing capacity,the maximum vertical cyclic failure load was 0.43 times of vertical static bearing capacity.When the vertical static load was 0.5 times of the static bearing capacity,the maximum horizontal cyclic failure load was 0.79 times of horizontal static bearing capacity.