Detection of Old Workings
Review of earlier geophysical work plus literature, setting out method selection and test site requirements ahead of field trials, for engineers assessing undermined ground before development.
by M van Schoor | February 2008
Microgravity, resistivity based methods including self potential, and time domain electromagnetics are identified as able to detect and delineate shallow old workings, with controlled source audio magnetotellurics useful below about 30 metres. How well each performs depends on target depth, the material filling the void and the overburden, and has never been quantified. Field trials were planned to close that gap.
R1500,00
Description
Related Products
Update of Coal Pillar Data Base, Strength Formula and Probability of Failure for South African Coal Mining
2012
Reviews how the failed and intact pillar record, tributary area loading and the safety factor concept have developed since 1960, for rock engineers and regulators.
What this report foundFailures continued after the safety factor approach was adopted, in pillars created both before and after it, so the record of failed workings has kept growing...
R1500,00
Failures continued after the safety factor approach was adopted, in pillars created both before and after it, so the record of failed workings has kept growing since the original 27 cases. The database was updated and re-analysed to revise the strength formula and to set out the probability of failure associated with pillar designs.
Determine Possible Means to Conduct Large Scale Frictional Ignitions Tests, and the Value of These to Coaltech
2017
A scoping exercise based on technical enquiries to mine safety organisations and discussions at an international conference, aimed at rock engineers and safety practitioners weighing test facility investment.
What this report foundNo operating full scale frictional ignition test facility was found anywhere in the world, and building one was judged expensive, impractical and unlikely to...
R1500,00
No operating full scale frictional ignition test facility was found anywhere in the world, and building one was judged expensive, impractical and unlikely to justify its cost against laboratory scale testing. Effort should instead go to small scale laboratory equipment using South African rocks, and to expanding geological data such as silica distribution and petrographic analysis.
Cleaning Near Moving Conveyors
2011
First phase of a two part investigation into conveyor cleaning practice at South African coal mines, covering the legal position, current mine practice and available machinery.
What this report foundConveyance legislation promulgated in 2008 and enforced soon after left the coal industry without a lawful way to clean near and under running conveyors.
R1500,00
Conveyance legislation promulgated in 2008 and enforced soon after left the coal industry without a lawful way to clean near and under running conveyors. The first phase defined the problem, recorded the cleaning practices mines already use successfully, and built a structured database of mechanised platform options worth pursuing. High risk areas remain drives, take ups, snub and tail pulleys and transfer points.