吸力式基础是海洋平台的一种新型基础形式，具有承载力高、成本低、可重复使用和适应各种复杂的海洋荷载环境等优点，在近海滩涂和深海石油开发中有广泛的应用。针对中国近海地质条件和海洋环境开展吸力式基础承载特性的研究，研制了离心机上电磁式、长历时、大负载、宽频率范围激振器，实现了对结构施加循环水平动荷载。进行了一系列海洋平台吸力式基础离心模型试验，揭示了结构振动荷载作用下基础变形失稳机理，得到了荷载强度和结构刚度对基础稳定性的影响。提出了能够考虑竖向荷载、水平荷载和弯矩联合作用、基于塑性力学上限定理的桶基-地基的三维极限分析方法。

The paper presents the results of centrifuge model tests performed to study the failure mechanism of suction bucket foundation of offshore platform under cyclic lateral vibration loads. Electromagnetic actuator with wide frequency range and heavy load used in the tests was developed in light of China’s offshore geological conditions and ocean environments. Two failure modes might happen: liquefaction in the early excitation and settlement-induced problem after long-term excitation. However, with increased stiffness of the large diameter cylinders, the pore pressures and the induced settlement decrease. A three dimensional limit analysis method by which the joint effect of lateral load, horizontal load and bending moment could be considered was proposed based on upper boundary theorem of plastic mechanics to simulate the soil-foundation system. The results of numerical analysis were basically in agreement with the centrifuge modeling results.