Recently, the Dalian Zhuanghe V Offshore Wind Farm project successfully completed the precise penetration installation of two new-type foundations—monopile-friction bucket foundations. The project is invested and constructed by China Three Gorges Renewables, with survey and design undertaken by CTG Shanghai Investigation, Design & Research Institute (Shanghai Institute).

The monopile of this foundation has a diameter of 8 meters, and the friction bucket has a diameter of 24 meters. By combining a large-diameter monopile foundation with a suction bucket foundation through grouting, this represents an innovation by the Shanghai Institute over conventional monopile and suction bucket foundations, addressing issues in the Zhuanghe sea area such as thick silt layers and highly undulating rock surfaces.

Under seabed conditions of deep weathered rock strata and medium-buried bedrock, conventional monopile foundations cannot obtain sufficient bearing capacity from the upper overburden soil and must be embedded into the underlying "bedrock." Rock-socketed construction requires large drilling rigs and related auxiliary equipment, entails long offshore construction cycles, and faces associated safety risks such as borehole collapse, greatly affecting project development and construction.

The monopile-friction bucket foundation improves the overall stiffness and horizontal bearing performance of the bucket body,overcomes the shortcomings of conventional foundations, can adapt to complex geology, saves engineering quantities, and reduces construction costs. It is suitable for areas in China with appropriate water depth and geological conditions, and has good prospects for engineering application.

Currently, the project is steadily advancing wind turbine hoisting and grid-connection commissioning, striving to achieve full-capacity grid connection within the year. The Shanghai Institute will firmly grasp the development direction of "one think tank and three highlands," continue to deepen the R&D and application of new offshore wind structures, promote cost reduction and efficiency improvement in the industry, and provide technical support for the large-scale, high-quality development of China's offshore wind power.