If you have access to OneMine as part of a member benefit, log in through your member association website for a seamless user experience.
|After the United States and Australia, South Africa has the largest. modern underground coal mining industry in the world. Historically, South Africa has been the cradle of many innovations in ground control, particularly in the area of pillar design. Today, South African mines are grappling with many of the same issues faced by their U.S. counterparts, including safety during pillar retreat operations, selecting the proper roof support, and maintaining long-term pillar stability. The author recently visited seven underground mines in the Mpumalanga, Free State, and KwaZulu-Natal provinces. Mining methods included longwall, room-and-pillar with continuous miners, and drill-and-blast. The mines represented a cross-section of geology and ground support practices. At each mine evaluations were made of the Coal Mine Roof Rating (CMRR), roof support practices, pillar design methods, and general ground control experience. The coal seams observed were generally thick (2-5 m), the depths of cover moderate (less than 200 m), and the roof rocks relatively strong (CMRR greater than 45). Unfortunately, the South African roof fall fatality rate is approximately three times greater than in U.S., perhaps in part because roof bolts seem to be more widely spaced in most South African mines. Roof bolting equipment was generally outdated, and the quality of bolt installation was a major concern. Pillar design, on the other hand, is quite advanced, and pillar failures are rare. Several novel partial pillaring techniques are employed, including "checkerboard" mining in which every other pillar is removed, 3-cut systems, and high-extraction mining where engineered final stumps are left by design. The paper also offers observations on ground control management techniques (including recently introduced Codes of Practice), the role of the mine inspectorate, and the status of the research community.|
Additional chapters/articles from the SME-ICGCM book Proceedings - 18th International Conference on Ground Control in Mining
|Pillar Collapse at Welgedacht Colliery, South Africa: A Case||Causes of Massive Directional Roof Falls in Room and Pillar||Catastrophic Collapse Of Highwall Web Pillars And Preventati||Mine Panel Collapse - Two Case Studies||Roof Geology Mapping In Underground Coal Mines||Electromagnetic Seam Wave Mapping Of Roof Rock Conditions Ac||Geological Conditions At Continuous Miner Sections; Examples||The Role Of Engineering And Geology In Analyzing Ground Cont||The Development And Use Of Risk Assessment Techniques To Ass||Time-Dependent Analysis Of Underground Opening Stability||Tekflex As A Sprayon Screen Replacement In An Underground Ha||Tunnel Deformation Monitoring "Action Levels" In Coal Mines||Skin Failure Of Roof And Rib In Underground Coal Mines||Application Of Polyurethane Injection For Rehabilitation Of||Design Considerations For Bump-Prone Longwall Mines||Design Methodology For Standing Secondary Roof Support In Lo||Modern Shield Technology: Better Than Ever But Still Not Per||Shield Monitoring To Forecast Severe Face Weightings At The||Monitoring Of Longwall Seal Behaviour For Permeability And S||Ground Control In South African Coal Mines - A U.S. Perspect||Rock Mechanics Issues In The Trona Patch||Highwall Augering In Ultra-Thick Western Coal Reserves: Uniq||Seismic Events Due To Underground Mining Activities||Control Technology For Roof Drill Operators||Resin Annulus Size Effects On Rebar Bolt Pull Strength And R||Roof Bolt Response To Shear Stress: Laboratory Analysis||Laboratory Study Of Shear Loading And Bolt Load Transfer Mec||Analysis Of Cable Bolt Performance Using Numerical Modeling||Roof Bolting Application In Longwall Mining In Indonesia And||Ground Control Design For Multiple Seam Mining Using Finite||Pillar Design Issues For Underground Stone Mines||Calibration Of The Analysis Of Longwall Pillar Stability (AL||Mine Convergence When Using Mobile Roof Supports In Pillar R||The Advance And Relieve Mining Method: A Horizontal Stress C||Localized Horizontal Stress And Its Effect On Ground Control||Prediction And Control Of Surface Subsidence Over Abandoned||Effects Of Mining On Underground Infrastructures In The Germ||Ground Deformation In The Case Of Underground Mining Of Thic||Prevention Of Time-Dependent Subsidence By Elimination Of Gr|