A case study of bolt loads in a trona mine retreat section.
Aachen International Mining Symposia, 4th International symposium on Roofbolting in Mining, Aachen, Germany, June 6-7, 2001. Aachen, Germany: Institut für Bergbaukunde I, 2001 Jun; :481-494
Researchers from the Spokane Research Laboratory of the National Institute for Occupational Safety and Health installed 39 instrumented, fully grouted bolts at six test sites in a trona mine retreat panel to study mine roof stability for the improvement of workplace safety. Variations in bolting at each test site included bolt spacing, bolt length, roof span, and location in the panel layout. At most test sites, two rows of instrumented bolts were installed, one in or near the intersection created during development and the other in or near the intersection created during second-pass mining. The most significant factor affecting bolt load was roof span. The highest loads were on the bolts installed in the intersections of the 6-m-wide entry. Mining-induced stress resulting from panel layout was the next most significant factor affecting bolt loading. Minor variations in bolt loading could be attributed to changes in bolt spacing and length.
Mining-industry; Rock-falls; Rock-bursts; Mining-equipment; Rock-mechanics; Geology
Aachen International Mining Symposia, 4th International symposium on Roofbolting in Mining, Aachen, Germany, June 6-7, 2001