Responses of wind turbine foundations in sand subjected to submarine landslides

The submarine landslides are massive underwater sediment movements on the ocean floor and can pose significant threats to offshore structures. Understanding the mechanism of submarine landslide-offshore structure interaction is essential for risk assessment. In this study, the centrifuge tests are conducted to investigate the responses of offshore wind turbines founded on four piles in sand subjected to the submarine landslides. The tests indicate that: (1) The liquefaction of the sand may occur within 1~2 meter in depth because of the induced excess pore water pressures. (2) The foundation settlements are largely depended on the dynamic impact. The settlements are 0.5 m for the 10-m-pile foundation and about 0.1 m for the 20-m-pile foundation. It is also found that the increasing pile length reduces the excess pore water pressure, soil deformation and foundation settlement. The effects of landslide viscosity on the foundation responses are discussed.