Ice-resistant performance evaluation of a downward-pressure-induced pile foundation for cold-region wind turbines

Sea-ice hazards in cold-region sea areas pose significant challenges to the structural safety of offshore wind turbines. Although traditional ice-resistant cone pile foundations can effectively reduce ice loads, their application to large-diameter piles involves a pronounced load trade-off: reductions in peak ice forces are often accompanied by substantial increases in wave loads. To address this issue, this study proposes a modular downward-pressure-induced (DPI) ice-resistant wind turbine foundation. A computational fluid dynamics-discrete element method coupled numerical framework, validated through scaled physical model experiments, is employed to investigate the dynamic evolution of broken ice interaction with the DPI foundation, including initial contact, accumulation-induced jamming, and subsequent dynamic release. The results show that while maintaining effective ice-resistant performance, the DPI foundation significantly reduces both horizontal and vertical wave loads, thereby alleviating the inherent design trade-off of conventional ice-resistant cone foundations, in which improved ice resistance is achieved at the expense of increased wave loading. Parametric sensitivity analysis further indicates that when the ice-guiding angle ranges from 25° to 35° and the circumferential arrangement angle ranges from 22.5° to 30°, the DPI foundation most effectively suppresses ice force-chain locking, resulting in optimal ice-resistant performance. This study provides useful insights for the coordinated control of ice and wave loads and for the lightweight design of pile foundations in cold-region environments.