Experimental Research on Scour Protection Range and Protection Effect of Large Diameter Monopile Foundation

[Introduction] Under the wave-current combinations during the service period of offshore wind turbine, local scour inevitably occurs around pile foundation, which threatens the overall stability and safety of offshore wind turbine. [Method] In this paper, the normal physical model test at a scale of 1∶30 was carried out for the wind power foundation with a diameter of 8.0 m to study the scour depth, sand cover, solidified soil protection range, and protection effect. [Result] The results show that due to the good hydrodynamic conditions considered in this test, the maximum scour depth is 0.133 cm. In this case, the 1 cm-thick sand cover with a splicing size of 1.0 m×1.0 m can meet the stability requirements. When solidified soil is adopted for protection, the protection range shall not be less than 5 times the pile diameter, and block stones shall be laid at the edge of solidified soil to avoid scouring at the lower part of solidified soil. [Conclusion] The test results can provide reference for scouring test and engineering design of similar projects.