Numerical study on soil springs stiffnesses of laterally loaded monopiles

• Published in: Marine georesources & geotechnology Vol. 43; no. 2; pp. 232 - 243
• Main Authors: Wang, Yang, Dai, Guoliang, Zhu, Mingxing, Jia, Zhirong, Wu, Jinbiao, Li, Bangxiang
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 01.02.2025; Taylor & Francis Ltd
• Subjects: Diameters; Dynamic response; Elastic analysis; finite element analysis; Finite element method; Mechanical properties; Modulus of elasticity; Monopile; Offshore; Pile foundations; pile-soil relative stiffness; Piles; Soil; Soil analysis; Soil investigations; Soil modulus; soil spring stiffness; Soils; Springs (elastic); Stiffness; Three dimensional analysis; Turbines; Wind power; Wind turbines
• ISSN: 1064-119X; 1521-0618
• DOI: 10.1080/1064119X.2024.2325540

Unlike traditional pile foundations, monopiles supporting offshore wind turbines usually have the characteristics of large diameter (D) and relatively low length-to-diameter ratio (L m /D). Accurate evaluation of the soil springs stiffnesses around the monopile is crucial for the design requirements and assessment of the dynamic response of offshore wind turbines. Over the past decade, a large number of initial stiffness models of lateral p-y spring have been proposed. However, limited research has been devoted to additional soil reaction springs, namely the rotational m-θ spring and pile base shear Q b -y b spring. Moreover, the contribution of these additional components is closely related to the pile-soil relative stiffness (K R ), and it is a challenge to consider their relationship in the design. In this paper, a three-dimensional finite element analysis of elastic soil is performed to systematically investigate the effects of pile D, L m /D and soil elastic modulus (E s ) on soil spring stiffness, and the effect of non-uniform soil is also discussed. The relationship between the initial load contribution ratio of each spring and the K R is clarified, and a new proposal for the soil springs stiffnesses considering the K R is put forward and verified for reasonableness.