Wind Farm Site Characterisation using MASW Survey

This study presents a non-intrusive geophysical investigation using Seismic Refraction and the Multi-channel Analysis of surface waves (MASW) techniques at the consented 10- wind turbine generator (WTG) locations at Tullo Wind Farm, in Aberdeenshire, Scotland. The aim was to provide geotechnical parameters including the ground stiffness profile at each turbine location. The results are intended to inform ongoing Site Investigation (SI) activity and inform detail design of turbine foundation across the site. At some turbine locations, the attenuation of relatively high frequency components of the transmitted seismic energy was recorded. This is most likely as a result of boggy nature of the near surface conditions. It is highlighted that there is a reduced confidence of the estimated P-wave velocity values for these cases. The S-wave velocity estimates including Vs30 were derived from MASW analyses. Data from most locations exhibited good dispersive characteristics that provided clear, laterally consistent phase-velocity frequency plots enabling 2D visualisation. However, a lack of dispersive behaviour at STI1, ST3 & TET3 locations limited the lateral extent of S-wave velocity determination. The deformation properties such as Elastic moduli were calculated based upon assumed densities of 1.8Mg/m3 for each geological units across the site.