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U.S. Department of Energy
Office of Scientific and Technical Information

Entry stabilization utilizing rib-bolting procedures. Rept. of Investigations/1991

Technical Report ·
OSTI ID:5304197
The danger to personnel, equipment, and pillar structure created by the spalling of a coal rib can be minimized by installing rib bolts. To assure that a configured support system will maintain a coal rib, the U.S. Bureau of Mines developed a rib bolt system based on a nonpreventable failure concept. A statistical equation quantitatively related the amount of rib retained to the bolt spacing and the width of the spalled material. Laboratory test results show that the equation accurately predicts the amount of material retained and confirm the validity of the support concept. The examination of rib bolting at a coal mine experiencing rib sloughage provides evidence that the effectiveness of the support can be related to the failure pattern of the spalled material. An analysis of roof and roof support reaction to rib sloughage at the mine indicated that the rib sloughage had little effect on roof stability. Although supporting ribs might not affect roof stability, laboratory test results indicate that the material retained by the support can sustain a load up to 20 pct of the intact compressive strength of the material.
Research Organization:
Bureau of Mines, Denver, CO (United States). Denver Research Center
OSTI ID:
5304197
Report Number(s):
PB-91-230276/XAB; BUMINES-RI--9366
Country of Publication:
United States
Language:
English