Dynamic responses of the shallow foundation of an onshore wind turbine

Wind is a dynamic variable, which produces rocking movements on wind turbines, and thus resulting in dynamic responses of foundations and the subsoil. This study attempts to examine the dynamic responses of the shallow foundation of an onshore wind turbine subjected to wind loads. To this end, a series of model tests considering different wind load conditions was carried out on a 1/10-scale physical model. The static responses, the dynamic responses and the dynamic amplification effects of the shallow foundation were subsequently measured and analysed. The results demonstrate that the dynamic responses of the wind turbine shallow foundation were visibly affected by both the mean wind load and the fluctuating wind load. At the rated wind speed, the maximum strain-based dynamic amplification factor (DAF) of the foundation baseplate reached as high as 1·65, the maximum deformation-based DAF of the foundation top was 1·14 and the maximum contact-pressure-based DAF on the downwind side was 1·14. In addition, the reliability of the physical model was discussed and the results were verified by comparison with the numerical data in the literature.