Finite Element Analysis Of Suction Anchors

In recent years, the exploitation of offshore oil went from shallow sea to deep-sea with the increasing demand of energy sources. Anchoring technology was one of the key technologies in deep sea platforms. Suction anchors, taking for the new anchoring foundation forms, had been greatly developed and gained wider application in this process. So the numerical analysis of suction anchors was helpful to understand it’s working mechanism and guide engineering practice.Based on the total stress method, this paper presented a two-dimensional FEM numerical model which studied on the penetration of suction anchors and a three-dimensional FEM numerical model which researched on suction caissons under the loading effect, by use of the finite element analysis software ABAQUS. Both were assumed in saturated soft clay. The two-dimensional model calculated the penetrated resistance and the height of soil plug. Also, the results were compared with the relative empirical formula and model test.The three-dimensional model calculated the bearing capacity of suction anchors in different loading angles and was verified by the laboratory test results. In the numerical analysis, the load-bearing characteristics, failure mechanism and the envelope diagram on the optimal mooring point were investigated. By fitting analysis of the numerical results, a simplified method for the estimation of the uplift capacity for suction caissons is described. The expressions developed in this paper take into account the influence of the aspect ratio of the caisson, angle of inclination of the loading and the undrained shear strength of the soil. At last, the influence of different parameters on the numerical results was studied by the method of changing parameters.