Details:

Personal Author:
Oyler, David ; Frith, Russell ; Dolinar, Dennis ; Mark, Christopher
Oyler, David ; Frith, Russell ; Dolinar, Dennis ; Mark, Christopher Less -
Corporate Authors:
Pittsburgh Research Laboratory (National Institute for Occupational Safety and Health)
Conference Authors:
International Conference on Ground Control in Mining (17th : 1998 August 4-6 : Morgantown, West Virginia)
Description:
Unusual circumstances may require that a longwall retreat into or through a previously driven room. The operation can be completed successfully, but there have been a number of spectacular failures which exposed miners to serious roof fall hazards. To help determine what factors contribute to such failures. the National Institute for Occupational Safety and Health (NIOSH) compiled a comprehensive international database of 130 case histories. The cases include five failures where major rock falls occurred in front of the shields, and six even more serious failures involving major overburden weighting. This suggests two room failure mechanisms The first is a roof fall type failure caused by loading of the immediate roof at the face as the fender narrows. The second is a weighting type failure caused by the inability of the roof to bridge the recovery room and face area, and affecting rock well above the immediate roof The data indicate that the roof fall type of failure is less likely when intensive roof reinforcement (bolts, cables, and trusses) is employed together with higher-capacity shields The overburden weighting failures, in contrast, occurred when the roof was weak and little standing support was used
Subject:
[+]
Mining

Source:
Proceedings of the 17th International Conference on Ground Control in Mining, August 4-6, 1998, Morgantown, West Virginia. Peng SS, Holland CT, eds., Morgantown, WV: West Virginia University, 1998 Aug; :44-53
Document Type:
Book Chapter
Genre:
Conference Publications
Collection(s):
National Institute for Occupational Safety and Health
Main Document Checksum:
[+]
urn:sha256:3b883c43be1dda904e0ee3aed38b63478751536e079c6205cf9fdd4702943c1c
File Type:

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