循环荷载下粉土中吸力基础承载特性试验研究

Experimental Study on Bearing Capacity Behavior of Suction Caisson Subjected to Cyclic Loading in Silt

摘要:

针对我国东海海域的粉土海床工况，基于模型试验，研究了循环荷载下吸力基础的荷载-水平转角响应规律，分析了吸力基础水平刚度与水平转角的相关特性，并建立了海上风力发电机使用寿命中吸力基础累积转角与循环次数的关系式。结果表明：循环荷载下吸力基础周围粉土的变形呈增加趋势，刚度随循环次数的增加而减小；加载或卸载过程中，吸力基础转动中心均呈明显的上移趋势，这将加速吸力基础的倾覆；卸载刚度与循环次数遵循对数增加关系。

Abstract:

A series of model tests was carried out on silt in the East China Sea to study the load-lateral rotation response charateristics and analyze the relationship between lateral stiffness and lateral rotation of a suction caisson subjected to cyclic loading. The accumulated rotation variation of the suction caisson with the number of loading cycles during the service life of offshore wind turbines was discussed. The test results show that the deformation of the silt around the suction caisson has an increasing trend under cyclic loading and its stiffness decreases with the increase of the number of cycles. The rotation point has an obvious upward trend whether the suction caisson is subjected to loading or unloading， which will accelerate the overturning of the suction caisson. The relationship between the unloading stiffness and the number of cycles follows a logarithmic increase.