Results 141 - 150 of 270

• Field Verification of Load Transfer Mechanics of Fully Grouted Roof Bolts
  1/1/1991 - Reports of Investigations
  The results of field tests on elastic bolt behavior showed that the anchorage length of grouted bolts installed in shale was slightly longer than the anchorage length determined in laboratory tests conducted in concrete blocks.
• Evaluation of Solid-Block and Cementitious Foam Seals
  1/1/1991 - Reports of Investigations
  The U.S. Bureau of Mines conducted explosion tests on various full- scale cementitious bulkheads used in abandoned mine areas to evaluate the ability of the bulkheads to withstand gas explosion overpressures of 20 psig. Tests were performed on 120-ft2 s...
• Self-Contained Self-Rescuer Donning Proficiency at Eight Eastern Underground Coal Mines
  1/1/1991 - Reports of Investigations
  This report presents the procedures used and findings from a U.S. Bureau of Mines evaluation of the self-contained self-rescuer (SCSR) donning proficiency of 243 miners at eight Eastern underground coal mines.
• Analysis of Acoustic Responses of Domal Salt Mine Samples
  1/1/1990 - Reports of Investigations
  The Bureau of Mines has developed an acoustic test for determining if a rock salt sample is from a "normal" nongassy salt face or from a gassy face where an outburst has the potential to occur.
• In-Mine Test of the Bureau of Mines Preproduction Wireless Survey System
  1/1/1990 - Reports of Investigations
  The Bureau of Mines preproduction wireless survey system (WSS) and its performance during an in-mine test are discussed in this report. The WSS was developed to reduce downhole surveying time in order to increase the efficiency of drilling long horizont...
• Probability of Making a Successful Mine Escape While Wearing a Self-Contained Self-Rescuer - A Computer Simulation
  1/1/1990 - Reports of Investigations
  In an effort to estimate the chances of a miner making a successful escape while wearing a self-contained self rescuer (SCSR), a computer simulation was developed.
• Rotary Drilling Techniques Used in the Beckley Coalbed
  1/1/1989 - Reports of Investigations
  The U.S. Bureau of Mines used a contact drilling strategy with short-collared assemblies in order to rotary drill long horizontal methane drainage holes in the Beckley coalbed near Glen Daniel, West Virginia. By decreasing the thrust and increasing the ...
• Pressure Monitoring and Observed Effects of Mining at the Oak Grove, AL, Coalbed Degasification Pattern
  1/1/1989 - Reports of Investigations
  The U.S. Bureau of Mines and the United States Steel Corporation evaluated the progress of methane drainage at the Oak Grove, Alabama, degasification pattern. Coalbed pressures were monitored between December 1981 and November 1985.
• Investigation of Methane Occurrence and Outbursts in the Cote Blanche Domal Salt Mine, Louisiana
  1/1/1988 - Reports of Investigations
  The Bureau of Mines conducted an investigation into the occurrence of outbursts of salt known to be responsible for explosions, fatalities, and damage in domal salt mines. The purpose of the investigation was to develop a basis for predicting these outb...
• Rapid (Grab) Sampling During Full-scale Explosions - Microscopic and Analytical Evaluation
  1/1/1988 - Reports of Investigations
  The Bureau of Mines has developed a system using a high-speed electropneumatic mechanism for the rapid (grab) sampling of dusts and gases during an explosion to monitor pyrolysis-charring in coal particles and combustion of pyrolysis vapors.