Mining Publication: Tests of Fibre-Reinforced Shotcrete at the Chief Joseph Mine, Butte, Montana
Original creation date: February 2005
Researchers from the Spokane Research Laboratory, National Institute for Occupational Safety and Health, in cooperation with engineers from the Department of Mining and Geological Engineering, Montana Tech, Butte, MT, conducted tests to evaluate the tensile strength, fiber count, and adhesion of shotcrete applied to panels at the Chief Joseph Mine, a research and training facility operated by Montana Tech. The tests were conducted in the mine ramp 45 m (150 ft) inward from the access portal at a 15.25-m- (50-ft) long test area divided into five 3-m- (10-ft) long sections. The shotcrete was applied with an Aliva 240.5 machine fitted with a predampener. Different amounts of fiber were entrained for each panel. Background data for the tests were obtained from earlier tests in Nevada, where the typical amount of fiber in the shotcrete is 6.54 kg/m3 (11 lb/yd3). All shotcrete was applied to a minimum thickness of 76 mm (3 in). Cylindrical cores were drilled at the wall-rock interface, and adhesion was tested after 28 days of curing. The goal of this research is to reduce the need to install multiple supports at the advancing face by creating a safer mining system that limits the time miners are exposed to unprotected roof.
Authors: LA Martin, JP Dunford, MM MacLaughlin, RR Cronoble
Conference Paper - February 2005
NIOSHTIC2 Number: 20030425
2005 SME Annual Meeting, February 28 - March 2, Salt Lake City, Utah, preprint 05-20. Littleton, CO, Society for Mining, Metallurgy, and Exploration, Inc., 2005 Feb; :1-6
See Also
- Diagnosing and Controlling Moisture-Sensitive Roof in Coal Mines
- Optimizing Secondary Roof Support with the NIOSH Support Technology Optimization Program (STOP)
- Overview of Coal Mine Ground Control Issues in the Illinois Basin
- Pillar and Roof Span Design Guidelines for Underground Stone Mines
- A Practical Method of Measuring Shotcrete Adhesion Strength
- Preventing Falls of Ground in Coal Mines With Exceptionally Low-Strength Roof: Two Case Studies
- A Shotcrete Adhesion Test System for Mining Applications
- STOP - Support Technology Optimization Program - 3.4
- Technology News 482 - Ground Support Safety Training Video
- Updating the NIOSH Support Technology Optimization Program (STOP) With New Support Technologies and Additional Design Features
- Page last reviewed: 9/21/2012
- Page last updated: 9/21/2012
- Content source: National Institute for Occupational Safety and Health, Mining Program