Embedded steel ring (ESR)–foundation connections are widely used in onshore wind turbines (WTs) to transfer the loads from the tower to the foundation. The load-bearing behaviour of the ESR–foundation connection greatly impacts on the structural integrity of onshore WTs under ultimate loads. The complex geometry, load-bearing mechanism and composite behaviour of the ESR–foundation connection present significant challenges for the optimal design of the connection. This paper proposes analytical equations to estimate the ultimate moment capacity of the ESR–foundation connection of onshore WTs. The load-bearing behaviour of the ESR–foundation connection was investigated through experiments on a small–scale model and numerical simulation on a large–scale model of the connection. A series of parametric studies were conducted to investigate the impact of key design parameters on the load-bearing behaviour of the ESR–foundation connection. The ultimate moment capacity, uplift resistance and extent of damage to the foundation were evaluated with respect to each parameter. The embedment depth of the steel ring was found to be the most significant parameter that impacts on the load-bearing behaviour of the ESR–foundation connection. About 90% of the bending loads are borne by the base flange-concrete and ESR wall–concrete contact surfaces. Based on the observed stress distributions and failure modes under ultimate loads, analytical expressions were proposed to estimate the ultimate moment capacity of the ESR-foundation connection.

嵌入式钢环 (ESR)-基础连接广泛用于陆上风力涡轮机 (WT)，以将载荷从塔架转移到基础。ESR-基础连接的承载行为极大地影响陆上WTs 在极限载荷下的结构完整性。ESR-基础连接的复杂几何形状、承载机制和复合行为对连接的优化设计提出了重大挑战。本文提出了用于估计陆上 WT 的 ESR-基础连接的极限弯矩容量的解析方程。ESR-基础连接的承载行为通过小比例模型的实验和大比例模型的数值模拟进行了研究。进行了一系列参数研究，以研究关键设计参数对 ESR 地基连接承载性能的影响。对每个参数的极限弯矩承载力、抗拔力和基础损坏程度进行了评估。发现钢环的嵌入深度是影响 ESR-基础连接承载性能的最重要参数。大约 90% 的弯曲载荷由基础法兰-混凝土和 ESR 墙-混凝土接触面承担。基于观察到的极限载荷下的应力分布和破坏模式，提出了解析表达式来估计 ESR-基础连接的极限弯矩能力。对每个参数的极限弯矩承载力、抗拔力和基础损坏程度进行了评估。发现钢环的嵌入深度是影响 ESR-基础连接承载性能的最重要参数。大约 90% 的弯曲载荷由基础法兰-混凝土和 ESR 墙-混凝土接触面承担。基于观察到的极限载荷下的应力分布和破坏模式，提出了解析表达式来估计 ESR 基础连接的极限弯矩能力。对每个参数的极限弯矩承载力、抗拔力和基础损坏程度进行了评估。发现钢环的嵌入深度是影响 ESR-基础连接承载性能的最重要参数。大约 90% 的弯曲载荷由基础法兰-混凝土和 ESR 墙-混凝土接触面承担。基于观察到的极限载荷下的应力分布和破坏模式，提出了解析表达式来估计 ESR-基础连接的极限弯矩能力。发现钢环的嵌入深度是影响 ESR-基础连接承载性能的最重要参数。大约 90% 的弯曲载荷由基础法兰-混凝土和 ESR 墙-混凝土接触面承担。基于观察到的极限载荷下的应力分布和破坏模式，提出了解析表达式来估计 ESR-基础连接的极限弯矩能力。发现钢环的嵌入深度是影响 ESR-基础连接承载性能的最重要参数。大约 90% 的弯曲载荷由基础法兰-混凝土和 ESR 墙-混凝土接触面承担。基于观察到的极限载荷下的应力分布和破坏模式，提出了解析表达式来估计 ESR-基础连接的极限弯矩能力。