海上风电大直径宽浅式筒型基础抗弯特性分析

风机属于高耸结构物，承受巨大的弯矩是海上风电基础区别于其他常见结构基础的重要特征．大直径宽浅式筒型基础是适应海上风电特征荷载作用的新型基础型式．筒型基础的直径、入土深度、顸盖及侧壁厚度是控制其抗弯能力的重要技术参数．结合某海上风电工程实例，采用数值分析方法，系统研究了不同尺寸特征参数对筒型基础传递及抵抗弯矩荷载的影响，揭示了弯矩荷载作用下宽浅式筒型基础的失效模式及基础转动点位置；研究了地基承载力设计中等效均质算法的合理性．研究表明：基础抗弯承载能力随筒型基础的直径及入土深度的增加而显著增长；在弯矩荷载作用下，筒周围土体出现贯通的弧形破坏面而在基础下方土体中存在曲边三角形的稳定区；对于实际工程中的上软下硬成层土地基，经等效均质化后，将导致计算得到的基础抗弯极限承栽力明显偏高．

Resisting Moment Behavior of Large Diameter and Shallow Buried Bucket Foundation for Offshore Wind Turbine

The wind turbine belongs to high-rise structure. The foundation of wind turbine must bear huge moment, which is different from other common structure foundations. The large diameter and shallow buried bucket foundation is a new foundation type which meets the requirement of the characteristic load of offshore wind turbine. The impor- tant technological parameters of bucket foundation for resisting moment are diameter, embedded depth, upper wall and lateral thickness. An offshore wind power project is taken as an example, and the impacts of the characteristic pa- rameters of different size on bucket foundation transferring and resisting moment load are systematically studied by numerical simulation. The failure mechanisms and rotating point position of bucket foundation are revealed under moment load. The rationality of equivalent homogeneous algorithm is studied in designing the bearing capacity of the foundation. Research shows that the bearing capacity of resisting moment increases significantly with the in- crease of diameter and embedded depth. Under the moment loads, arc failure surface occurs in the surrounding soils of bucket foundation, and the curved edge triangle stability region is found under the foundation soil. In practical engineering, the bearing capacity of resisting moment is obviously improved after the equivalent homogenization of the stratified foundation soil which contains the soft layer on top of the hard layer.