Study on scour protection method for offshore wind turbine foundations based on rapid consolidation of in-situ seabed sediments

Abstract

With the growing global demand for clean energy, offshore wind power is rapidly developing as a sustainable and green energy source. However, the action of ocean waves and currents makes the area surrounding monopile foundations highly susceptible to scour, which significantly undermines the bearing capacity of the foundation piles. To ensure the safe operation of the superstructure, effective scour protection measures are essential. Nevertheless, existing protection method often suffer from failures, incomplete coverage, or complex construction procedures, making it difficult to achieve long-term and reliable scour protection for offshore wind turbine foundations.This study combines both micro-scale soil mechanics experiments and macro-scale scour model tests to address this issue. The micro-scale experiments revealed that the hydration products generated from the interaction of curing agents with water and soil are the key mechanisms enabling the cementation and solidification of seabed sediments. When the cement-soil ratio is 1∶1, the water-solid ratio is 0.3, and the sodium silicate content is 0.3 of the mixture, underwater solidification can be achieved within 5 minutes—dramatically shortening the curing time compared to previous studies requiring 2 hours, 24 days, or even 72 days.Furthermore, scour tests demonstrated that the solidified soil under these conditions can effectively resist water flow, reducing scour depth by up to 80%, thus providing significant protective effects. In conclusion, this paper proposes a rapid in-situ seabed sediment solidification method for scour protection, offering an engineering reference for the mitigation of scour hazards in offshore wind turbine foundations.

Keywords

offshore wind turbine foundations / scour protection / rapid curing / sediment solidification