Numerical Trials for the Soil-Spudcan Interface of Self-Elevating Units

Abstract

Abstract This paper describes the development of a numerical model of a jack-up leg supported on the seabed and the study performed in order to analyze the interaction at the interface between the soil and its spudcan. Self-elevating units or jack-ups are widely used for offshore operations and the strength of their whole structure is to be ensured for the environmental conditions encountered during the operations. This is why the determination of the soil-spudcan interface is a major challenge since it depends on a wide range of factors, such as sea conditions, properties of the soil, geometry and material of the structure, etc. In light of the unpredictable and non-linear behavior of the marine environment and the soil, it is necessary to develop further studies on this subject to reduce uncertainties and to ensure the safety of offshore structures, as most of the failures in the offshore oil platforms are related to foundations. To do so, different approaches have been used: • Abaqus/ Standard and Abaqus/Explicit solvers; • Rigid bodies and deformable bodies afterwards; • Three kind of meshes: ○ Lagrangian mesh; ○ Arbitrary Lagrangian - Eulerian mesh; ○ Coupled Eulerian - Lagrangian mesh. To validate the model and the results obtained numerically in the end of the project, a comparison with an analytical calculation of the spudcan penetration has to be performed, based on the geometry of the structure and the properties of the soil.