Nonlinear 3D FE-Stability analysis of suction pile

Suction piles are used to anchor off-shore constructions (e.g., oil platforms) in the sea ground. For the implementation, an under-pressure is created inside the device. The task is to make sure that the suction pile does not fail due to buckling of the friction skirt. The consideration of possible imperfections in the friction skirt as well as the interaction of the suction pile with the surrounding sea ground is particularly important for this verification. State of the art to calculate the maximum possible suction presser before collapse was to use radial springs with non-linear stiffness to characterize the surrounding soil’s supporting effect. This new approach, using 3D Finite Element Simulation with highly non-linear material behavior representing the soil results in significantly increased working loads and economically improved design or installation options. To further validate the suction pressure capacity obtained with the new methodology, a verification with a series of simulation using different spring stiffnesses was carried out. Based on this, it is concluded that the results obtained by the new methodology are not only economically more valuable but rather also more physically correct.