New method quickly assesses underwater landslide risk for offshore turbines

Heriot-Watt researchers have developed an advanced simulation tool that accurately predicts underwater landslides caused by offshore wind turbines.

The new method enables developers to assess seabed stability not only at the design stage but throughout a wind farm’s lifespan, helping to optimize placement and ensure long-term resilience.

Underwater landslides—when sections of the seabed suddenly shift—can impact the stability of wind turbines, particularly in areas with soft seabeds and gentle slopes.

While engineering structures like monopiles (the foundations of some offshore wind turbines) can contribute to seabed stress, predicting the extent of this effect has been challenging.

The Heriot-Watt tool quickly and precisely identifies potential landslide zones, helping developers strengthen seabed stability and avoid costly downtime.

Qingping Zou, professor of coastal dynamics at the Lyell Center, Heriot-Watt’s Global Research Institute for Earth and marine sciences, said, “Offshore wind farms represent millions of pounds of investment and have the potential to transform our energy supply.

“To protect these assets, developers need accurate and efficient tools to assess seabed stability—not just when choosing turbine locations, but as an ongoing part of wind farm operations and monitoring.

“Our method gives a clear understanding and fast prediction of how the seabed will respond once turbines are in place, ensuring that sites are most suitable and projects remain safe, resilient and productive.”

Predicting seabed shifts at every stage

The Heriot-Watt tool combines soil mechanics theory with a shear strength reduction method to analyze how the seabed holds together under stress.

Benjian Song, a Ph.D. student at Heriot-Watt, said, “We tested our method on 3D models of the ocean floor, including real-world locations like Silver Pit, off the coast of Lincolnshire—a region with a history of submarine landslides.

“Our tool maps potential landslide zones and assesses how turbine foundations influence seabed conditions over time. Crucially, it also solves a major issue for existing models, which struggle to simulate multiple landslides occurring simultaneously.”

Foundations and storms influence seabed stability

The research, published in Ocean Engineering and Soil Dynamics and Earthquake Engineering highlights how turbines’ foundations and storm activity influence seabed stability.

Dr. Cathal Cummins from Heriot-Watt’s School of Mathematical and Computing Science explained, “Monopiles, which are large steel cylinders driven into the seabed, are widely used to anchor offshore wind turbines.

“Our simulations show that these structures create stress concentrations that can affect long-term seabed stability.

“We also found that increasing the diameter and depth of monopiles enhances overall slope stability, offering a potential design solution to mitigate risk.

“Storms further weaken the seabed, and the dynamic loads transferred through monopiles can reduce soil strength.

“Our tool allows developers to factor in these effects and make decisions about wind farm resilience.”

A new standard for offshore wind farm stability

Dr. Cummins says the team is keen to collaborate with offshore developers to integrate seabed stability assessments into wind farm design and maintenance.

“Our tool is a fast, accurate way to predict underwater landslides, with minimal computational requirements.

“By using it, developers can ensure their offshore wind farms remain stable and reach their full renewable energy potential.”