Cutable and Variable Yield Cement Cribbing Successfully Support 84 Mine Longwall Cut Through Entries

Bookshar, William
Organization: International Conference on Ground Control in Mining
Pages: 13
Publication Date: Jan 1, 1998
The development of increasingly more sophisticated and powerful retreat longwall equipment has led to ever wider and longer panels. To maximize gateroad development efficiency, provide for effective face recovery, andlor reduce ventilation pressures, entries are cut across longwall panels in advance of longwall retreat mining. These entries must be supported to prevent falls of immediate roof in advance of the face. Recently, cut through entries and predriven recovery room entries have been supported with various combinations of roof bolts and passive support. The cost and relative success of these support systems has varied considerably. Eighty-Four Mining Company, Fosroc, and Sub-Technical have developed and implemented an efficient, yielding, multiple component, cement crib to support longwall panel cut through entries and pre-driven recovery rooms. The cutable crib consists of an inexpensive flyash cement pillar poured in a bag, within a temporary metal form. The form is moved to a subsequent cutable crib location after the initial hardening of the flyash pillar. The remaining entry height between the mine roof and the top of the flyash cement pillar is filled with a specially designed bag filled with Fosroc's Tekset cement formulation. The diameter of the pillar and thickness of the Tekset bag are designed to accommodate the anticipated front abutment loading and entry convergence.
Full Article Download:
(2755 kb)

Additional chapters/articles from the SME-ICGCM book 17th International Conference on Ground Control in Mining (ICGCM)

Gateroad Pillar Extraction Experience at Jim Walter Resource
Stability of Backfilled Cross-panel Entries During Longwall
Mining Through In-panel Entries and Full-face Recovery Room
Cutable and Variable Yield Cement Cribbing Successfully Supp
International Experience with Longwall Mining into Pre-drive
Analysis of Geologic and Geotechnical Conditions and Their E
Comparison of Ground Conditions and Ground Control Practices
Application of Microseismic Monitoring to Longwall Geomechan
Control of Hard-to-Collapse Massive Roofs in Longwall Faces
A Study of Periodic Weighting of Longwall Supports
Effects of Panel Mining Sequence and Retreat Direction on th
Controlling Roof Beam Failures From High Horizontal Stresses
Roof Control Under Conditions of Shallow Depth and High Hori
Assessment of Roadway and Yielding-pillar Performance During
Practical Stress Modeling for Mine Planning
The Design of Room and Pillar Mining Systems in the UK
Geotechnical Planning and Development of the BHP Minerals Sa
Coal Pillar Life Prediction in the Vaal Basin, South Africa
An Analytical Approach to Determine Stress Distribution in L
In Situ Strength Testing of Rocks with the Borehole Penetrom
Performance and Safety Considerations of Hydraulic Support S
A Decade of Mobile Roof Support Application in the United St
A Critical Study of Strata Behaviour During Extraction of Pi
Progression of Longwall Gateroad Support as Conditions Chang
Application of the Coal Mine Roof Rating, Derived from Drill
The Effects of Reduced Annulus in Roof Bolting Performance
Laboratory and In Situ Results of a Slip Nut Yielding Rock B
Field Monitoring of Rock Bolting Performance in Weak Roof St
A Case Study of Bolt Performance in a Two-entry Gateroad
Automated Temporary Roof Support Systems: An Update
Safety and Productivity Innovations in Mechanized Bolting
Factors Influencing Intersection Stability in U.S. Coal Mine
Analysis of the Effect of Rate of Extraction on Strain Devel
Analysis of Panel Stability for Post-Mining Slurry Injection
Development of Timedependent Surface Subsidence Over the Tot
Transversely Elasto-Plastic Analysis of Surface Subsidence A
Landslide Occurrence and Causation in Steep Slope Areas of A
Rock Bursting and Seismicity During Ramp Development, Lucky
Advances in Remote Sensing Techniques for Monitoring Rock Fa