Study On Bearing Capacity Of Offshore Wind Power Suction Bucket In Silty Clay

China has already developed a plan to achieve a non-fossil fuel consumption ratio of 25% by 2030.As a type of clean energy,wind power is being comprehensively developed and utilized.Currently,compared to leading foreign countries in offshore wind power construction,China’s offshore wind power construction is relatively lagging behind.Some core and key technologies need to be solved and widely promoted,and ensuring the stability of offshore wind turbines is one of the key technologies.The offshore wind power structure foundation is mainly subject to loads such as wind,waves,ocean currents,and the weight of the upper structure.Currently,the offshore wind power foundations that are widely used are the single-pile foundation in the nearshore areas and the bucket foundation in the slightly further offshore areas.This article compares and analyzes the bearing performance of shallow water single-pile and single-bucket foundations by calculating the wind and wave data monitored in the East China Sea from2010 to 2020 and converting it into wind and wave loads applied on offshore wind power foundations.Furthermore,it also statistically analyzes the bearing performance of the enlarged single-bucket foundation under deep sea wind and wave monitoring data.In addition,this article conducts research on the bearing performance of the four-bucket foundation and provides methods to improve the bearing capacity of the bucket foundation.The main contents of this article are as follows:(1)Dynamic triaxial tests were carried out on the samples of silty clay obtained by seabed drilling.By summarizing the states of large and small strains of soil samples at different depths,the deformation state and dynamic elastic modulus parameters of silty clay at different depths under dynamic cyclic loading were summarized.(2)A numerical model was established using typical single bucket and single pile offshore wind power foundations to compare and analyze the bearing performance of suction bucket and single pile foundations under ultimate loads.Further,the monthly maximum wind wave data for the 11 years from 2010 to 2020 at the shallow water area survey stations were collected,and the wind wave data were converted into wind wave loads and applied to the offshore wind power foundation using an amplitude curve.The bearing performance of the suction bucket foundation and the single pile foundation under extreme wind wave loads was compared and analyzed,and the deformation characteristics of the suction bucket foundation under dynamic limit loads were obtained.(3)The maximum wind speed and wave height of each month from 2010 to 2020 at the deep-sea survey station are calculated,and the wind wave data are converted into wind wave loads and applied to the offshore wind power suction bucket foundation in an amplitude curve.The bearing performance of the suction bucket foundation is analyzed.(4)An improved suction bucket was designed to improve the strength of soil in the bucket by grouting.The effect of increasing the strength of soil in the bucket on the bearing capacity of the suction bucket was studied.(5)The relationship between the bearing capacity and bucket spacing of a four bucket foundation under different directions of load is simulated,and the effect of improving the soil strength in the bucket on the bearing capacity of the four bucket foundation is studied.