Results 41 - 50 of 79

• Technology News 448 - Improving the Performance of Longwall Gob Gas Ventholes
  3/1/1995 - Technology News
  The absence of fundamental scientific and engineering principles in the design and placement of gob gas ventholes can cause difficulties for mine operators when gas emissions increase because of a change in mine design or because variable geologic condi...
• Modeling the Effects of Longwall Mining on the Ground Water System
  1/1/1995 - Reports of Investigations
  A hydrologic-subsidence investigation was performed to evaluate the effects of longwall mining on the local groundwater regime through field monitoring and numerical modeling.
• Timing and Duration of Subsidence Due to Longwall Mining
  1/1/1995 - Reports of Investigations
  Subsidence data gathered by the U.S. Bureau of Mines over a series of longwall panels in the Pittsburgh Coalbed were studied to obtain insight as to the role of time in the subsidence process. These results were then compared to data from three other si...
• The Effects of Roof and Floor Interface Slip on Coal Pillar Behavior
  1/1/1990 - Conference papers
  This U.S. Bureau of Mines paper discusses the importance of an interface slip mechanism between the coalbed and the surrounding strata in controlling the extent and pattern of stresses and deformations in a coal pillar.
• 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...
• Clay Veins: Their Occurrence, Characteristics, and Support
  1/1/1987 - Reports of Investigations
  The Bureau of Mines investigated the physical characteristics of and roof instability problems associated with clay veins. This was accomplished by observing and mapping clay veins in surface and underground mines. The occurrence and origins of clay vei...
• A Review of the Mechanisms of Gas Outbursts in Coal
  1/1/1987 - Information Circulars
  Outbursts are sudden and violent releases of gas and coal that result from a complex function of geology, stress regime, and gas pressure and content. The Bureau of Mines has reviewed methods for prediction and mitigation of such outbursts in use worldw...
• Methane Contents of Oil Shale From the Piceance Basin, CO
  1/1/1987 - Reports of Investigations
  The Bureau of Mines determined the gas contents of 135 oil shale samples obtained from approximately 630 ft of core drilling. Drilling was done within a projected mining zone of the Cathedral Bluffs Mine, located in the Piceance basin of western Colorad...
• Methane Content of Gulf Coast Domal Rock Salt
  1/1/1984 - Reports of Investigations
  This report considers the results achieved when 80 domal salt samples were tested for gas content by dissolution in a controlled atmosphere chamber.