Numerical study of spudcan penetration in loose sand overlying clay

Spudcan installation in sand overlying clay carries a risk of potential punch-through failure. This paper investigates the penetration resistance of spudcans on loose sand overlying clay soils using large deformation finite element analysis. Comparison with existing experimental results shows that the Mohr–Coulomb yield criterion with unchanging shear strength parameters simulates well the behaviour of loose sand, for which strain softening is not significant. The paper quantifies the effects on the punch-through behaviour of the spudcan of the main input parameters, including the undrained shear strength of the underlying clay, and the thickness, friction angle and stiffness of the upper sand. The current design guideline, SNAME [2], significantly underestimates the peak bearing capacity of the spudcan in comparison with the numerical results.