Geotechnical Investigation For A Single Entry Design For Longwall Mining

Singh, Madan M.
Organization: International Conference on Ground Control in Mining
Pages: 9
Publication Date: Jan 1, 1982
Currently longwall coal mining operations require at least 3 entries on both the headgate and tailgate ends because of ventilation and safety requirements. Driving of entries, however, is a slow and costly process. Often it is a bottleneck in longwall development. Single entry gateroads are permitted in Europe and commonly used there. This study entailed ascertaining the feasibility of using a single entry in the United States, without sacrificing safety. This design was conducted for an operating longwall mine in the Black Warrior coalfield in Alabama, An understanding of rock loads and consequent support requirements is prerequisite to the design and successful demonstration of the single entry system. Efforts in this regard were directed at determining center (packwall) support requirements for various single entry widths. Critical to the analysis is knowledge of the nature and extent of side abutment stresses. In collecting geological and geotechnical information relating to the stability of the single entry, Engineers International, Inc. engaged in the following: ? Examination and inspection of the single entry demonstration at the Sunnyside Mine in Utah. Severe ground conditions and unacceptable levels of entry closure were experienced there prior to the tailgate phase. Observations at the mine presented a clear perspective on possible ground control problems for future single entry designs. ? Reconnaissance inspection and classification of roof rock conditions. ? Detailed mapping of roof structure in the areas to be instrumented. ? Installation of convergence stations in the longwall headgate to monitor roof movement during mining. ? Measurement of side abutment stresses in a yield pillar in the area of the convergence measurements. ? Measurements of coal fracture distribution by the detail area method. ? Rock properties determinations of roof, coal, and floor rocks; samples obtained by core drilling. ? Determination of floor bearing capacity by in-situ testing.
Full Article Download:
(1852 kb)

Additional chapters/articles from the SME-ICGCM book Proceedings Second Conference On Ground Control In Mining

A New Approach To The Design Of Multi-Entry Developments For
Manifestation Of Mine Pressure And Its Relations To Overlyin
Geotechnical Investigation For A Single Entry Design For Lon
Roof Falls And Caving In Longwall Mining Operations
Support Resistance And Roof Behaviour Of A Longwall Face Wit
State Of The Art Testing Of Powered Roof Supports
Some Structural Aspects Of Designing The Shield Supports
Design Considerations For Angle Bolters
Machine Design Parameters For High Seam Truss Bolting Applic
Design Trade-Off For Angle Roof Drilling
Hydraulic Tensioning Of A Birmingham Roof Truss
Current Trends In Roof Truss Hardware
The Search For A Method To Provide Warning Of Coal And Gas O
Methods Used To Monitor Roof Geology And Entry Supports
A Method For Estimating Western Coal Strengths From Point Lo
Coping With High Lateral Stresses In An Underground Illinois
Alternatives For Controlling Cutter Roof In Coal Mines
Remote Sensing Techniques In Mine Planning - Applications An
The Use Of A Graphic Mini-Computer System As A Rock Mechanic
Greater Safety With Increased Productivity Coal Mining Opera
Critical Roof Span Approach To Selection Of Proper Coal Mine
Roof Bolt Bond Tester; A Device For Nondestructive Testing O
Remote Control Roof Bolting
Development Cooperation Between Operator And Manufacturer -
Research, Development, And Use Of Steel-Fiber-Reinforced Con
TV Borehole Inspection And Vacuum Testing Of Roof Strata
Use Of Automated Resistivity System To Locate Potential Subs
Control Of Mine Subsidence Utilizing Coal Ash As A Backfill
Surface Flooding-Considerations For Mining Facilities Site S
The Formation And Effects Of Transient Abutment Stress Durin
Some Technical Considerations When Mining Under Bodies Of Wa