Analysis And Field Testing Of Presupport Application In Coal Strata

Dizon, J. D.
Organization: International Conference on Ground Control in Mining
Pages: 10
Publication Date: Jan 1, 1990
Conventional strata control methods (i.e. roof bolts. cable trusses) are not always effective for ground control of very weak coal strata. An alternative method, termed presupport. is being investigated by the U.S. Bureau of Mines. In this paper structural modeling of presupport conceuts and field teatinn of a DresuDuort application is presented. Pinite-elem&; modeis indicate that forepoles significantly lower beam stresses in the roof strata overlying a coal seam. but they cannot he expected to prevent or reduce I roof strata failure at the coal face due to the presence of a high stress concentration at that location. However, their presence near the coal face is needed to sustain the fall of roof if it does occur. Because of an ever present severe stress concentration at the coal face, it would appear that stresses could exceed material strengths, causing local structural damage, especially if the rock is very weak. Therefore previous coal face positions along an entry may have a higher than normal probability of roof fall. In the field investigation. a loorcost air injection test has thus far shown promise as a tool for evaluating that effects of forepoling on the roof strata. Observations of coal mine en- tries in which forepoles have been installed indicate forepoling is effective in controlling very weak roof strata.
Full Article Download:
(3138 kb)

Additional chapters/articles from the SME-ICGCM book Ninth Conference on Ground Control Mining Proceedings (ICGCM) 9th

Multiple-Seam Mining - A State-Of-The-Art Review
Design Aspects In Multiple-Seam Mining: Case Studies
Jenmmar Compression Roof Control System
Specialty Truss System And Their Performance
A Case Study Of Grouted Roof Bolt Loading In A Two-Entry Gat
Analysis And Field Testing Of Presupport Application In Coal
Development Of Roof Stitching As A Method Of Support In Indi
Control Of Roadway Closure In Underground Coal Mines By Side
An Application Of Fem Back Analysis Method To Mine Roadway
Controlled Blasting During Drifting In Hard Rock Mine
Field Test Results On Dyna-Rok And Dyna-Rok Plus Anchors
Mine Pillar Stability Analysis Using Fem Methods - Two Case
An Analytical Approach For The Estimation Of Pillar Strength
International Conference On Ground Control In Mining Design
A New Rock Mass Failure Criteria Based On Rate Of Movement
Practical Consideration In Longwall Support Selection
Mine-Wide Monitoring Applications In Ground Control Research
Longwall Stability Analysis Of A Deep, Bump-Prone Western Co
Stability And Control Of Immediate Roof Of Fully Mechanized
An Analysis Of Longwall Shield Cycle Effectiveness By Polyco
The Impact Of Three Longwall Coal Mines On Streamflow In The
Progressive Failure Of The V-Day Mine And A Comparison With
Controlling Subsidence Effects Using Partial Backfilling
Potential Of A Void Diffusion Model To Predict Longwall Subs
The Use Of Rim- To Detect Geologic Anomalies In The Clarion
The Effect Of Hazardous Geologic Structures On Gateroad Stab
Improved Source Location And Evaluation Of Seismic Events Ov
Application Of Short-Term Time-Dependent Plate Loading Tests
Determination Of Classification Parameters For Clay - Bearin
Intrinsic Response Of Borehole Pressure Cells Laboratory Cal
Application Of Sliding Roof Bar Powered Support For Thick-Se
Drainage Of Water From Abandoned Mines By Horizontal Drillin
A Statistical Analysis Of Falls Of Ground In South African C
Three-Dimensional Analysis Of Mine Dump Point Stability
Birth Of A Longwall-Initial Planning To Post-Subsidence Miti
Progressive Hangingwall Caving And Subsidence Prediction At