Alternative methodologies for evaluating explosion-resistant mine ventilation seals.
Sapko-MJ; Weiss-ES; Harteis-SP
30th International Conference of Safety in Mines Research Institutes. Johannesburg, Republic of South Africa: South African Institute of Mining and Metallurgy, 2003 Oct; :615-640
The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) recently conducted full-scale explosion experiments that evaluated the strength characteristics of various seal designs used for safely isolating worked-out areas in underground coal mines. Large-scale explosion tests were done within the multiple-entry section of PRL's Lake Lynn Experimental Mine using the only currently accepted test method endorsed by the Mine Safety and Health Administration for seal design in U.S. mines. These tests are labor-intensive, expensive, and can interfere with other critical underground safety and health research conducted by NIOSH. Therefore, PRL developed an alternative seal evaluation method based on a hydrostatic pressure loading concept that can facilitate the in situ testing of seals in an operating mine. Two chambers within the Lake Lynn Experimental Mine and one within PRL's Safety Research Coal Mine were used for hydrostatic pressure loading various seal designs. The results from tests in these chambers compare favorably with those from the large-scale explosion tests in the multiple entries. Preliminary size-scaling relationships for predicting the strength of standard seal designs as a function of entry size are also presented. In addition to testing seal designs at the required 20-psi static pressure level, the new facilities also allow the determination of the seal's ultimate failure pressure. This new approach shows promise as an alternative evaluation method for improving mine sealing technologies. This, in turn, will enhance the safety of underground workers.
Explosion; Coal-mining; Underground-mining; Mine-seals; Mine-disasters
NIOSH Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
30th International Conference of Safety in Mines Research Institutes