Field monitoring and analysis of an onshore wind turbine shallow foundation system

Investigations of the soil-foundation interaction behaviour and transfer of energy from the wind to the ground and the subsequent transmission of elastic waves to the surrounding areas have not been conducted in Ontario. Indeed, very few seismic monitoring studies have been conducted globally around wind farms. It has been found that turbines predominantly produce vibrations related to structural resonances and blade passing frequencies. Spectral peaks correlated with wind speed, and spectral composition and energy was found to be modified with distance and was dominated by surface waves. This paper discusses a study of the effect of the wind-structure interaction on the behaviour of a turbine foundation and the generation of ground-based vibrations around a working commercial wind turbine. The field monitoring system and meteorological instrumentation are described in this paper and the responses of the structure and the surrounding ground due to the fluctuating wind-field are discussed.