The paper presents the development of a three-dimensional finite-element model for pile tests in dense Dunkirk sand, conducted as part of the PISA project. The project was aimed at developing improved design methods for laterally loaded piles, as used in offshore wind turbine foundations. The importance of the consistent and integrated interpretation of the soil data from laboratory and field investigations is particularly emphasised. The chosen constitutive model for sand is an enhanced version of the state parameter-based bounding surface plasticity model, which, crucially, is able to reproduce the dependency of sand behaviour on void ratio and stress level. The predictions from three-dimensional finite-element analyses, performed before the field tests, show good agreement with the measured behaviour, proving the adequacy of the developed numerical model and the calibration process for the constitutive model. This numerical model directly facilitated the development of new soil reaction curves for use in Winkler-type design models for laterally loaded piles in natural marine sands.

中文翻译：

---

敦刻尔克密集海沙中侧向荷载桩的有限元模拟

本文介绍了在Punk项目中进行的三维有限元模型在稠密敦刻尔克沙中的桩试验的开发。该项目旨在开发用于海上风力发电机基础的侧向受力桩的改进设计方法。特别强调了对来自实验室和现场调查的土壤数据进行一致和综合解释的重要性。选择的砂土本构模型是基于状态参数的边界表面可塑性模型的增强版本，该模型至关重要地能够再现砂土行为对空隙率和应力水平的依赖性。在实地测试之前进行的三维有限元分析预测表明，该行为与测得的行为非常吻合，证明了开发的数值模型和本构模型的标定过程的适当性。这个数值模型直接促进了新的土壤反应曲线的开发，该曲线用于Winkler型天然海洋砂土中横向加载桩的设计模型。