A Preliminary Investigation Into the Geotechnical Interpretation of Geophysical Logs
Compares a full suite of downhole sondes against geotechnical core logging over the 5 m above three coal seams, for geologists and rock engineers assessing roof conditions.
by Lesley S Jeffrey | October 2004
Geophysical logging of boreholes above three Witbank seams identified clay rich matrices, stiffness changes, bedding planes and the principal stress direction, and picked up fractures in 30 to 75 per cent of cases. Core logging found most of the same features faster, so routine use was not recommended unless stiffness and stress direction matter.
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