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TerraDat is a UK based specialist geophysical ground exploration company that operates worldwide. Geophysical surveys provides a rapid, non-invasive ground investigation tool that has many applications ranging from locating buried manmade structures through to characterising geological and hydrogeological features. This TerraDat Technical Note deals with how geophysics can benefit ground engineering problems encountered in the wind energy industry.
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Geophysics for On-Shore Wind Energy DevelopmentsW
ind
En
ergy
Over recent years TerraDat has gained a wealth of experience providing geophysical services to the Wind Energy industry. By working alongside many major wind farm developers, TerraDat has developed a suite of geophysical techniques ideally suited to the needs of most onshore wind farm developments. Through maximal understanding of the subsurface, these techniques allow optimisation of turbine location and foundation design.
A combination of magnetic, ground conductivity and microgravity surveys are used to map archaeological features as well as other geo-hazards such as buried structures, mine workings, solution features, voids and fracture zones.
Resistivity tomography surveys are used to provide information on the shallow geology and soil electrical properties for earthing design. This approach is more accurate than the traditional 4-pin method since it is possible to derive more reliable resistivity values. Thermal properties of the soil can be analysed by using a thermal resistivity meter to acquire data either at surface, or within trial pits.
Seismic surveys provide information on the depth and strength (rippability) of underlying ground materials. Seismic data is acquired using surface-based P and S-wave refraction and /or MASW techniques. On sites with limited survey area or variable geology, seismic data can be obtained from boreholes. By combining the derived seismic P and S-wave velocities with density information, it is possible to calculate Poisson’s Ratio and a range of elastic moduli, i.e. Shear, Young’s and Bulk.
Archaeological Surveys
Rock Head and Ground strength Surveys
Geotechnical information
Earthing Measurements
TechnicalNote
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P-wave velocity Model
Resistivity vertical electrical sounding (left) and tomographic section (right)
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Resistive bedrock
P-wave refraction (Layered velocity model) and MASW (S-Wave)
Seismic refraction survey
TerraDat (UK) Ltd - Tel (08707 303050)www.terradat.co.uk
Contact Simon Hughes for more info; [email protected] Simon Hughes for more info; [email protected]
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