Helical piles are a common foundation type for offshore wind turbines (OWT), widely utilized because of their low construction costs and straightforward design. However, the response of helical piles subject to combined loading is highly complex, and related research is relatively limited. In this paper, the coupled Eulerian-Lagrangian (CEL) analysis is employed to model the ultimate limit states of a typical HELICAL PILES subject to combined loading and quantify its load-bearing capacity. A series of CEL analyses of the helical piles was employed to provide insight into the impacts of the embedment depth ratio, helix diameter ratio, and soil strength ratio on the loading behavior of helical piles subject to combined loading. Based on the parametric study results, a set of closed-form expressions was used to estimate the uniaxial bearing capacity coefficient, V-H, V-M, H-M, and V-H-M failure envelopes of the helical piles were established, and an example problem was presented to illustrate the applicability of the developed design procedure. The findings from this study are highly valuable for understanding the load characteristics of helical piles subject to uniaxial and combined loading, contributing to improving the safety design level of the OWT foundation.
Liu et al. (Tue,) studied this question.