Application of non-coaxial constitutive model to numerical calculation of bearing capacity of suction bucket

When the suction bucket is subjected to vertical load, it is very easy to induce the integral shear failure of the foundation surrounding the bucket. However, it is not reasonable to ignore the non-coaxial phenomenon, which is caused by the principal stress rotation. Based on the UMAT of FEM software ABAQUS, the non-coaxial model is adopted into the numerical analysis of vertial suction bucket foundation's bearing capacity problem. The results show that the non-coaxial model has little influence on the integral shear failure mechanism of the foundation, but it not only has a visible softening effect on the bearing capacity-settlement curve, but also decreases the vertical ultimate bearing capacity of the foundation. It's safe to take the non-coaxial model into the assessment of the foundation's bearing capacity, which is often determined by the vertical displacement.