Monopiles are the most commonly used foundation type in offshore wind power, and pile-soil interaction is a key factor in pile foundation design. The recommended formulas in existing design specifications apply only to the two extreme soil types—sand and clay. However, transition soils with both sandy and clay-like properties (non-zero cohesion and non-zero friction angle)—silty soils—are widely distributed worldwide. Considering only a single property may lead to uneconomical and unreliable pile foundation designs. In addition, conventional p?y models are developed for monopiles with a single length-diameter ratio, while studies on generalized p?y models that account for varying length-diameter ratios are limited. In this study, a finite element model of monopile-soil interaction is established using ABAQUS. A calculation formula for the horizontal ultimate bearing capacity of silty soil is derived, while the influence of varying length-diameter ratios parameters are also considered, the influence of horizontal ultimate bearing capacity and monopile lengh-diameter ratios on the lateral load-displacement response of monopiles is quantified , furthermore, a p?y model for monopiles with different length-diameter ratios in silty soil is proposed. Finally, the model's accuracy and applicability are verified through comparative analysis of pile foundation cases.
