Driving of headings with a pilot borehole
The purpose of the research project was to demonstrate the benefit of a large diameter (60 cm) pilot borehole, drilled into the coal seam before driving the heading. The technique adopted to bore the hole and ensure its support after reaming is described. Before reaming, a small diameter pilot longhole has to be made, the position of which is controlled by a probe measuring the natural gamma radiation of the rock strata. The report presents the results of a programme involving the measurement of the natural gamma radioactivity of the Campine coal seams and their roof and wall. The findings indicate that it is possible to detect an important shale mass at a critical threshold of 20 pulses per second. This demonstrates that the gamma probe could have been used to guide the hole.
Bibliographic Reference: EUR 13101 FR (1991) 39 pp., MF, ECU 4, blow-up copy ECU 5
Record Number: 199110412 / Last updated on: 1994-12-02
Original language: fr
Available languages: fr