A Study of Periodic Weighting of Longwall Supports

Richardson, Archie
Organization: International Conference on Ground Control in Mining
Pages: 7
Publication Date: Jan 1, 1998
Periodic weighting of longwall supports occurs during retreat ofthe face under certain geologic conditions. Strong stratain the immediate and main roof tend to cantilever over the gob, weighting the supports periodically. The distance between weighting peaks, as well as the intensity ofperiodic weighting, is determined by the suength and thickness of roof members, their location relative to the seam, the frequency of joinling, and characteristics of the gob. In this paper the effects of varying several of these variables ate investigated using block modeling. The models are calibrated against a published case history of periodic weighting in the Pittsburgh Seam. It is concluded that block modeling is a useful tool for correlating measured support pressure histories with expected modes of strata behavior in the roof, with potential for predicting shield behavior in new geologic enviromnents.
Full Article Download:
(1486 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