Updated CPT-based p–y formulation for laterally loaded piles in cohesionless soil under static loading

The p–y method is currently the most popular design method to predict the response of piles to lateral load. The authors had previously used numerical methods to develop a cone penetration test (CPT)-based p–y formulation for piles in sand and this has subsequently been shown by independent verification to show considerable promise. This paper addresses some of the uncertainties associated with the original p–y formulation by examining the influence of pile bending stiffness, the presence of a water table, the cross-sectional shape of the pile and soil non-homogeneities. Numerical experiments are presented examining these four effects and lead to an updated proposal for a CPT-based p–y formulation. This formulation, which is consistent with the original proposal, is validated against three-dimensional finite-element calculations and data obtained from a full-scale offshore monopile foundation supporting a wind turbine.