Numerical evaluation of existing p-y models for the laterally loaded pile in clay

This is the authors' abstract. We don't add key points for this paper.

This paper presents a numerical investigation of the lateral response of single piles in undrained clay, commonly used as foundations for oil and gas platforms and offshore wind farms. The study compares the p-y model in the current API code with two newly proposed models intended for the updated API code, using a series of two-dimensional finite element simulations. The results show that the new p-y models offer excellent descriptions of the load transfer curve, while the current API model provides good predictions when the correct ultimate soil resistance is applied. Additionally, 108 three-dimensional simulations were performed on piles with varying aspect ratios and soil conditions to further evaluate the new models. The findings indicate that p-y curves are influenced by the failure mechanism around the pile, particularly for piles with large stiffness and low aspect ratios, where rotational failure leads to decreased resistance. Quantitative analysis reveals that while the prediction error for p-y models is typically under 10%, it increases significantly with pile-soil stiffness. For short, rigid piles, ignoring the failure mechanism and additional resistance can result in up to 50% underestimation of pile response.