Mapping of Old Bords and Pillars Revisited
Desktop review of recent unmanned aerial and underwater vehicle systems and how they compare with borehole scanning, for engineers assessing the stability of old underground workings.
by Michael van Schoor (CSIR) | December 2019
Mapping abandoned, inaccessible bord and pillar workings comes down to two options: borehole deployed laser or sonar scanning, or sensors carried in by unmanned vehicles. Drone mounted laser scanning for air filled voids and sonar carried by small submersibles for flooded workings were judged the most promising, but intrinsic safety, deployment and the risk of losing equipment still favour borehole methods for occasional use.
R1500,00
Description
Related Products
Mapping of Old Bords and Pillars Revisited
2019
Desktop review of recent unmanned aerial and underwater vehicle systems and how they compare with borehole scanning, for engineers assessing the stability of old underground workings.
What this report foundMapping abandoned, inaccessible bord and pillar workings comes down to two options: borehole deployed laser or sonar scanning, or sensors carried in by...
R1500,00
Verification of the New Coal Pillar Strength Formula and Investigations Into the Prediction of Pillar Life in Witbank and Highveld Coalfields
2004
Covers pillar load and strength estimation, the limits of tributary area theory, and the extraction gains available from revised strength formulae, for rock engineers designing bord and pillar workings.
What this report foundLaboratory testing showed coal specimen strength rising linearly with width to height ratio and falling exponentially with specimen size, the size effect...
R1500,00
Laboratory testing showed coal specimen strength rising linearly with width to height ratio and falling exponentially with specimen size, the size effect becoming insignificant beyond about 2 m diameter. The slope of that relationship was the same for coals from different mines, while the intercept varied with specimen size.