Abstract: Based on the mesh regeneration and mapping of field variables, a large deformation finite element model was developed. The uplift capacities of circular plate anchors in immediate break away case and no break away case were investigated using this model. It is assumed the anchors are buried horizontally in uniform clay. Compared with small strain finite element calculation, large deformation analysis overcomes the severe mesh distortion of soils around the plate anchor, which makes it possible to describe the variation of uplift capacity during the whole pulling-up process. According to several numerical examples under immediate break away condition, the effects of anchor roughness and overburden pressure on uplift capacity are studied. It is found as considering soil weight, uplift capacity of deep anchor is lower than the sum of corresponding capacity in weightless soil and the overburden pressure, and the upper limit is the capacity under no break away condition. It is shown that the soil weight puts slight effect on no-break away-capacity. The relationship between no-break away-capacity and initial embedment of anchor is offered.

Key words: finite element methods, large deformation, clay, bearing capacity, plate anchor