A new soil reaction model for large-diameter monopiles in clay

Abstract

Considering the limits of the traditional p-y method and the omission of the non-negligible additional lateral resistance components for large-diameter monopiles, the effects of rotational soil flow and pile tip lateral components on the soil-pile lateral behavior are discussed in detail. A new unified soil reaction model is proposed to obtain a more accurate prediction of the lateral behavior of monopiles supporting offshore wind turbines (OWTs), which consists of the lateral p-y spring, the base moment (Mbase-θ) spring and the base shear (T-u) spring. This model is suitable for cases of slender, semi-rigid and rigid piles, and can be modified to include the effects of different soil flow mechanisms, large diameter and base lateral resistances. From the analysis results, the model proposed in this study provides a better prediction and is more appropriate for the design of OWT foundation. The traditional p-y method underestimates the lateral resistance and stiffness of the soil-pile system, is overly conservative and is not economical for the design of OWT foundations.