New boreholes for the test were drilled in the BK area of the GTS. Once drilled, the boreholes were photographed with a specialised borehole scanner. This provides a 360° camera view of the geology of the borehole. This continuos image of the borehole corresponds to the true depth. This allows spherical fracture parameters such as azimuth and dip of the selected fracture to be derived

drilled borehole scan
Section of the newly drilled boreholes. The red line corresponds to the location of a fracture.
 Location of EFP at Grimsel

 

Effective Field Parameters (EFP)- Geological & Geophysical Investigations