Estimation of spudcan penetration in variable sand deposits with the Arbitrary Lagrangian Eulerian Finite Element Method

Offshore jack-up rigs are most commonly founded on large-diameter conical spudcan foundations, which are frequently designed using traditional analytical methods for shallow footings. This paper presents the design of a spudcan installed off the coast of Tunisia. The maximum penetration depth of the footing under the available preload is predicted by a combination of analytical techniques, 2-dimensional axisymmetric modelling and 3 -dimensional Finite Element Methods (FEM) using large strain arbitrary Lagrangian-Eulerian (ALE) techniques. Spudcan penetration based on FEM simulation of CPT soil profiles forms the basis of a comparison with results from the Society of Naval Architects and Marine Engineers (SNAME) guidelines. Particular attention is given to model calibration using the limited site investigation data available. Results are presented for the effect of penetrating footings on the behaviour of neighbouring footings, showing good agreement with conventional prediction methods.

Automated summary

This paper presents the design of a spudcan foundation installed off the coast of Tunisia, using traditional analytical methods. A combination of analytical techniques, 2-dimensional axisymmetric modeling, and 3-dimensional Finite Element Methods (FEM) with ALE techniques is used to predict the maximum penetration depth of the footing under the available preload. The comparison between FEM simulation results and SNAME guidelines is based on the spudcan penetration determined from CPT soil profiles simulated by FEM.